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Polar M400 GPS & Activity Tracker Watch In-Depth Review


Today, Polar has announced their latest watch, the M400.  This running focused GPS watch also contains day to day activity tracking (i.e. steps and sleep) along with smartphone connectivity.  The unit priced at $179US/€159EUR, is very competitively placed in the market, significantly undercutting a number of models in the same segment as it.  It’ll start arriving in stores in a couple weeks.

I’ve been using the unit for the past month as both as a day to day activity monitor as well as a GPS running watch, and thus have a pretty solid feel for things.  Because I’m on both a final production unit and final production firmware, I’m comfortable enough with where things stand to call this an in-depth review versus a first look.

To be clear, Polar sent me over an M400 to start testing with until retail availability.  Like always, I’ll be shipping that back to them in Finland in the next little bit and going out and getting my own via regular retail channels.  That’s just the way I roll.

Lastly, at the end of the day keep in mind I’m just like any other regular athlete out there. I write these reviews because I’m inherently a curious person with a technology background, and thus I try and be as complete as I can. But, if I’ve missed something or if you spot something that doesn’t quite jive – just let me know and I’ll be happy to get it all sorted out. Also, because the technology world constantly changes, I try and go back and update these reviews as new features and functionality are added – or if bugs are fixed. So – with that intro, let’s get into things.

The Executive Summary:


Looking for the quick and simple version of this review?  Here’s the low-down of the M400.  As noted above it’s Polar’s second GPS watch that integrates activity tracking, following the much more expensive V800 multisport watch.  The M400 is designed as a runner’s watch, but blends in support for other activities such as cycling and…horse back riding.  Given that it’s a runner’s watch however, it doesn’t support cycling sensors, nor horse gait pods.

With the internal accelerometer the unit will track steps, distance, and sleep (along with calories), throughout your day.  It doesn’t however use the internal accelerometer to give you cadence while running nor pace/distance on a treadmill – you’ll need a footpod for both of those.

The battery life gets about 8-hours in GPS-on mode, like most watches in the category, and gets about three weeks in regular day to day watch time/activity tracker mode.

Like most Polar watches it includes a number of ‘Smart Coaching’ features.  However, one unique feature being introduced with the M400 is the Running Estimator option, which estimates how long it’ll take you to complete your run of a set distance at the current pace you’re running – thus taking the complex mid-marathon mental math out of the equation.  They’ve also added in PR support (Personal Records/Bests), which will tell you each time you break a new PR for a given distance/time/benchmark.

Lastly, the unit is well waterproofed at 30-meters, despite using just a standard micro-USB connector.  Though, while it is waterproofed, it won’t give you heart rate underwater, as it only supports Bluetooth Smart heart rate transmission and not the analog frequency used on some of Polar’s other water-friendly watches.

To get a feel for things I put together this quick walk-through video following my first run with the watch.  I go through all the major menu’s as well as some of the mid-run functions.  Enjoy!

Overall, I think this is a very solid contender at a price point that’s incredibly competitive compared to units like the Garmin FR220 (at $80 more) and the TomTom Runner.  After using it for about a month, I’ve really got no major complaints about the unit.  It exceeded all my expectations and does so at a sweet price.  Polar got it right here.

Unboxing & Versions:

The M400 comes in two color variants (white and black), and two package variants (with the HR strap, and without).  For the purposes of this unboxing, I have the black variant without the heart rate strap (I already had a HR strap).  However, I’ve also included photos of the white banded version as well.

To start, we’ve got a new fangled box design for Polar where you can actually see the product you’re buying.  Very nice!



Inside, you’ll have exactly two pieces of hardware, seen below.  They are the watch itself and the USB cable.  In the event you bought the heart rate strap bundle, you’ll have that too.


Here’s a closer look:


The watch as noted above comes in black or white, in my case I’ve obviously got the black version.  The strap is a bit different from past Polar watches, and almost feels ‘soft’.  Sorta like one of those super-soft t-shirts.  It’s kinda hard to explain, but the rubber is really nice (yes, it’s strange saying that).



On the back you’ve got a standard micro-USB port.  While it has a small cover on it, the port is internally waterproofed to 30-meters.  Yes, thirty meters.  This specific internally deep-waterproofed USB port has been making the vendor rounds for a while now but nobody bit and actually put it in a product.  Definitely excited to see it show up here.  Typically internally waterproofed USB ports haven’t been terribly awesome long term (past ones have only been rated to 1-meter at 30 minutes), so here’s to hoping this new version is as awesome as they claim.

(Update Nov 2015: One thing we have seen a spike in during 2015 is failures of the USB port, primarily due to corrosion. Interestingly, in the October timeframe we started seeing Polar ship a slightly different USB port arrangement on the M400’s. Whether or not it fixes things is still to be determined.  On the bright side, Polar has swapped out pretty much everyone’s units without question.)



Oh and in case you’re curious, this USB cable goes in that plug.  The other end simply goes to your computer, or any other USB port you’ll find on this little blue marble of a planet.


Looking at the screen on the unit, it’s a 128x128px high contrast black and white screen.  It’s incredibly sharp and identical to that of the V800, though with a plastic covering instead of glass:


Lastly, for those who prefer a less dark watch, here’s a quick look at the white variant of the watch:




Next, let’s compare some sizes and weights.

Size & Weight Comparisons:


The unit weighs in officially at 56.6g and is officially 11.5mm thick – I measured it at 55.5g, which is close enough for the purposes here.  The watch saved weight compared to the V800 by going with a plastic screen instead of glass, as well as nixing metal for plastic.  That said, it doesn’t feel cheap.

Next, let’s look at the size of the unit compared to the V800, then we’ll look at rolling pins.  As you can see in the next three pictures, it’s very similar, but the M400 is just a smidge smaller than the V800, mostly due to the slight rounding.


And here, the lack of additional metallic layer slightly reduced the profile as well.



Next, the rolling pin.  You’ll see the M400 as the 3rd from the right.  These are roughly ordered by size.  Here’s the full lineup:

(Left to Right: Garmin FR910XT, Garmin Fenix2, Suunto Ambit3, Suunto Ambit2, Suunto Ambit2S, Polar V800, Polar M400, Polar RC3 GPS, Garmin FR620)


Note that on the Garmin front, the FR220 and FR620 share the same exterior shell specs, so you can mentally just swap the colors there to get an estimate on size.

Here’s a look at the depth of the watches.  In this case the rolling pin is held exactly level upside down, allowing you to see how thick the watches are by looking at the gap to the most excellent Ikea table.


And finally, a closer look at the three Polar offerings.  As you can see both the M400 and V800 are slimmer than the RC3, and they also forgo the plastic shell area at the top/bottom of the RC3 that hides some electronics.


From a thickness perspective the watch is actually just slightly thinner than the Garmin FR220/FR620, so it might make it the thinnest GPS-integrated watch on the market.  It is also skinner (width) as well as shorter (height) than the FR220/FR620.  Good stuff!

You can see this thinness when the unit is located on my wrist.  Here’s a look at things from a few different angles:



And finally, here’s a picture of the black edition on The Girl’s wrist (she’s petite, at 5’2” tall).  My wrist size is 17cm (or about 6.5 inches).  The Girl’s is 14cm (or 5.5 inches).


She was carving cakes when I requested her wrist, hence why her hands are so dark looking (from the chocolate).  That said, she did find the black version a bit big on her wrist.  I’m checking to see if the white version is smaller as a strap.  I’ll update accordingly.


As I said above, I don’t think there’s a thinner all-inclusive GPS watch on the market today.


First up is running with the M400.  To begin you’ll first want to configure your user profile settings to ensure accurate calorie numbers, so this includes your gender and such.  Next you’ll also likely want to plug it in to your computer to ensure the firmware is up to date.

With those two minor tasks out of the way, it’s time to head outside.  The M400 includes predictive GPS capabilities which allow it to minimize how long it takes to find GPS satellites outdoors.  I’ve generally found it quite fast and on par with most other new GPS watches in the market with similar technologies.  Even while travelling, it has sometimes only taken a few seconds in a new country to find GPS.


While you’re finding GPS signal you can select which sport you’re going to do. In our case, we’ll choose running, but you can easily just scroll up or down in the menus to change the sport.  It’s at this point that it’ll go off and find your already paired heart rate strap (via Bluetooth Smart).  Once found it’ll show the heart rate value (BPM) on the screen.


Once ready (with GPS showing 100%), you can press the red button to begin recording the session.  This means it’ll start the timer and begin recording your distance, pace, location and other metrics.  These will then be shown on the screen for you in various data pages.


Each data page contains a configurable number of metrics.  This is an improvement over the previous Polar RC3 whereby you couldn’t really customize the data fields.  With the M400, you can customize all of the fields to the same extent as the much more expensive V800.  All of this customization is done online via Polar Flow:


While running you’ll get instant pace via GPS, along with your distance.


I found the instant pace responsiveness quite easy to pace by, and you can see a small snippet of that in the summary video at the beginning of this post.

You’ll also get your heart rate information displayed in a variety of manners including as straight beats per minute (BPM), as well as heart rate zones.


These zones are configurable online via Polar Flow.  You can have Polar figure them out for you, or you can override them for a given activity type.


New to the Polar lineup is Estimated Completion Time.  This function can be enabled via the ‘Timers’ option, and allows you to enable and then configure a data page that will give you the estimated time of completion of your run.  Prior to the start of the run you’ll specify how long the run will be (such as 5K):



Then while running the unit will show you how much time is remaining.  This is sorta like the Virtual Partner found on other units, but rather instead of showing you how far ahead/behind a pace you are, it’s showing you how long until you’re done.


Of course, not everyone is out to race or finish in a specific time.  If you’re more of the wandering type the M400 includes a ‘Back to Start’ function, that will show you the direct line back to the start.  Note that this does NOT follow your exact route to your current point, but rather is just a compass that points you directly back to the starting point.


This function relies upon you moving to function however, since it’s not a magnetic compass but rather one that takes into account your current speed.  If you stop moving, you’ll get notified:


This is quite a competitive feature to be found on a watch at this price point.  For example, the Garmin FR220 at $80 more doesn’t have this functionality contained in it (nor does the FR620 at $220 more).

In the event you’re still lost and ‘Back to start’ can’t help you, you can pause the watch at any time to go phone a friend for help.  To do so simply tap the lower left button and it’ll bring you to a paused screen:


Unfortunately, Polar still doesn’t allow you to see your current run data fields while paused, so you’re stuck with the main screen seen above with just the elapsed time that displays a moment later.  When you’re ready to resume you just tap the red button.

Finally, when you’re ready to end your run you’ll go ahead and hold down the bottom left button again to end the run.  At the conclusion of which you’ll be given stats about the run including how far you went, the time, calories as well as training benefit type, lap summary and individual lap detail information.



New to the Polar lineup though is personal records (PR’s), which the unit will track for various distances/times.  For example, this PR here for longest distance run (it happened to be my first run with the watch):


PR’s are a handy way to see training advancement for a given sport profile, especially if you routinely use the watch and are focusing on various specific distances to try and better times at.

Once you’re back at your phone or computer you can upload the activity to Polar Flow, which is Polar’s online training log site.


(Note: The ‘Training Load’ dots below each activity do NOT appear with the M400, but only with the V800 that’s also in my account. To be clear, you won’t see those Training Load Recovery items with just a M400 in your account.)

It’s here you can go ahead and dive into the training log for a given activity:


This includes viewing the details of both manual as well as automatic laps, which are recorded independently of one another.  Manual laps are ones where you press the button, whereas automatic laps can be configured for a set distance (such as every 1 mile or 1 kilometer):


Additionally, you can change the map view between a street map and satellite or terrain maps, which include the ability to also overlay lap information.


Finally, at the top of each session you have summary information regarding the activity, which in this case tested the limits of my hot weather running adaptation.  You can see a bit of the imperfections of the GPS based altimeter though (or, Polar’s site), whereby this pancake flat run did show some ascent/descent oddities.  Conversely, I saw some rather accurate elevation numbers on other runs while watching the display on the watch itself as I ascended/descended some hills.


Note that this training log information is available regardless of whether you are indoors or outdoors, or which sport mode you use.


The unit includes the ability to switch into a cycling mode, which allows you to customize cycling specific screens such as speed (usually shown as MPH/KPH).  These screens can be configured ahead of time on Polar Flow.

You can change screens (training views) just like in running mode, as well as configure any of the training targets seen on Polar Flow for cycling:


While the M400 can’t connect to any speed/cadence sensors, it can still connect to your heart rate strap in the cycling mode.  Once you’re ready to head for a ride you’ll go ahead and switch into the cycling mode by simply pressing up/down until you’re on that screen.  This also supports an indoor cycling mode where you can just capture heart rate data too.


Afterwards, if outdoors your routes will show up on Polar Flow as cycling-specific workouts, complete with speed-related metrics (versus pace-related ones):


Of course, the M400 is primarily a running watch, but even then, it still makes for a handy cycling stand-in if you don’t cycle very often and don’t care about cycling cadence data (or speed/distance while indoors on a trainer).  I’d suggest picking up a $10 cheap bike watch mount so you can mount it on your handlebars, allowing you to more easily see the data screens.

Other Sport Modes/Profiles:


Beyond the standard running and cycling modes, the unit can also be used with any of the custom sport modes found on Polar Flow (many more than displayed below):


These modes have specific calorie burn algorithms, which is part of the reason you can’t go rogue and create your own mode.  Note however that while there is a swimming mode, there’s no lap/distance tracking in either indoor or outdoor swimming (like the V800 will have later this fall).  Further, unlike the V800 the M400 will NOT capture heart rate data underwater.

Smart Coaching & Training Functions:

The Smart Coaching functionality has always been a core aspect of many Polar products. These features were aimed at providing a more cohesive feedback loop to users on how to train in a structured manner.  Much of this functionality was focused on heart rate aspects.

For example, there’s Running Index, which acts as a way to determine how efficient you are.  This information is displayed at the completion of a run:


Further, it’s shown online in the training log:

image(Note: The ‘Training Load’ dots below each activity do NOT appear with the M400, but only with the V800 that’s also in my account. To be clear, you won’t see those Training Load Recovery items with just a M400 in your account.)

You can then swing over to Polar’s site to see how that ranks compared to others.


Next, the unit will give you a training type after each workout that tells you what type of training it was – such as a tempo workout or a steady state workout.  In addition, it’ll give you an understanding of the training load from that workout, which can help you plan recovery.



The Polar M400 also includes two different structured workout modes (in addition to a free-for-all mode), starting first with a super basic interval timer.  This timer allows you to setup two-step workouts using time or distance (or both combined).  Such as a 5-minutes on, then 30-seconds off type workout.  For each segment it’ll give you a countdown of how much time is left.


The interval timer does support the ability to add both warm-up and cool-down portions, as well as to mix rest and work portions (such as a distance-based work followed by a time-based recovery).

The second option for workouts is far more powerful though, which is Polar’s full blown workout creator via Polar Flow.  In this, you can create workouts with all sorts of structures.  These structures can include goals like heart rate targets based on distance or time.  In November, Polar will also add to Flow the ability to create pace/speed targets.

This area is divided into three sections: Quick, Race Pace, and Phased.  Below is an example of a complex phased workout.  Whereas ‘Quick workouts’ have simple targets (such as a set distance or time).  And again, you can always just go out and run and record/manage it yourself.


You can see I’ve created a simple interval structure above with a 10-minute warm-up followed by 4x(1-mile work, 90-second rest).  Each of the targets then has associated heart rate zones with them.  These are then previewed below:


Next, these workouts can be assigned to given days on your calendar so they’ll automatically appear on your watch on the right day.  Alternatively, you can simply tag them as ‘Favorites’ and then access them via the favorites menu on the watch.

Once you select a workout to start, it’ll walk you through each phase of the workout:


There’s then a dedicated data screen during each phase showing you the target.  In my case, for this first phase I selected a warm-up target of any valid heart rate zone, which is why you see the range from 95 to 170bpm.  It then shows 9 minutes and 44 seconds remaining in the workout section, before it’ll iterate to the next section.


In its current state the workout functionality is basic compared to other competitors, but functional for many workouts.  Once Polar adds in the ability to specify pace/speed targets (November), as well as the ability to do post-workout analysis comparing planned versus actual, it’ll start to become much more powerful.

Daily Activity Tracker:


The M400 follows in the footsteps of the V800 and includes a daily activity tracker.  This activity tracker allows you to monitor your daily step count throughout the day, which in turn also feeds into the total calorie expenditure.

While it will give you distance, it won’t do so until it sync’s with Polar Flow at the end of the day (a bit of an annoyance given most other devices can do it internally).


You can view your daily activity throughout the day via a progress bar that’s accessible either through the watch menu, or via the home page if you add it to the watch face.

You can further dive into this information for any day in your history log as well, should you want to look back at some past day and see the breakdown of daily activity versus training log:


Next, all of this is sync’d to Polar Flow online, which allows you to see it both via a web browser as well as the Polar Flow mobile app.  Below is an example of yesterday using the desktop web view:


You’ll see it tracks my total steps on the left side (6,676), as well as the distance below it (3.21 miles).  Further down you’ve got how much sleep I got (6hrs and 43 minutes), along with an overview of my day as a time slice.  The M400 doesn’t require you do anything to track sleep, it just does it automatically (which is great!).

Inactivity alerts trigger after I’ve been seated too long.  It’ll give you one warning alert before it goes ahead and marks an inactivity mark on your ‘record’ a few minutes later.

I can change both that view as well as my daily activity goal status by toggling the left/right arrows.


Meanwhile, the daily activity goal is shown on the left side as broken out into different categories in terms of how you can achieve it.


For days that are still in progress it’ll give some rather interesting suggestions on how you could fulfill that activity goal:


Overall the activity tracker on the M400 is good, but not great.  I’d really like to see the ability to add steps to my home screen (not just a progress bar), as well as see my exact walked distance each day.  That’s sorta the baseline for even $59 activity trackers like the FitBit Zip (and every other activity tracker out there) – so I expect it on a product three times as much.

Smartphone Integration:

Like the V800 and Polar Loop, the M400 includes smartphone integration that enables it to upload completed workouts via Bluetooth Smart to your smartphone.  Further, it also allows you to transmit daily activity information like steps, sleep and distance walked to Polar Flow via the mobile app.

Now unfortunately at the time of this writing the only thing that I didn’t have full access to was the mobile app updated to sync with the M400.  While it’s the same app as the V800 and the Loop, the production version seen online doesn’t support the M400 yet, so I couldn’t fully test this function from a sync perspective.

However, the app will pull from Polar Flow, so activities do show up there from the M400, even when they weren’t sync’d that way.

I’ll be looping back and updating this section in the coming week or two once Polar releases the production version of the app that supports the M400.  I don’t expect too many issues here though since the V800 phone sync works fairly well for me and the M400 is really just a mini version of the V800.  Of course, it’ll still be something I test to ensure nonetheless.

In the meantime, I simply use the Polar FlowSync on my desktop computer, which synchronizes the content quite easily via USB cable:


Regardless of which way you sync the data though, it all ends up on Polar Flow. There is no local analysis of the data on your computer without the data first going to Polar Flow online (web service/site).

Sensor Support (Bluetooth Smart):


The M400 today supports Bluetooth Smart heart rate straps, and in a future firmware update will also support Bluetooth Smart footpods.  It does not support Bluetooth Smart Speed/Cadence sensors for cycling (nor is it planned to).

On the heart rate side, you can use any Bluetooth Smart HR strap with the unit.  On the Polar front that’d be the Polar H6 or H7.  It doesn’t much matter to this specific unit which one, since the unit itself can’t use the analog frequency of the H7 for underwater connectivity.  However, if you use gym equipment and want to display your heart rate there the H7 strap is the way to go.  I have tested it with a number of other heart rate straps (such as the Wahoo TICKR, Mio Link, and the Scosche Rhythm+) without issue.


When using a heart rate strap you’ll get heart rate displayed on the device as you’d expect.  This includes both current BPM, as well as zone information.  All of this is configurable via Polar Flow online:


Again, down the road in a firmware update they’ll add footpod support for indoor running on a treadmill which will gather cadence and pace as well as distance.  Note that without the footpod the unit will not gather running cadence information.

Day to Day Watch Functions:

The M400 works as a solid day to day watch.  Outside of a few days in Vegas at Interbike I’ve been wearing it globally on my wrist in day to day life including meetings and workouts.

While the unit won’t automatically set the time from GPS, it’s easy enough to change in the menu’s in a few quick clicks (this coming from someone who changes it about 3-6 times a week).

You can set a single alarm, which can be configured as once, daily, or weekday only (Monday-Friday):


In addition, you can change the default main screen of the watch to a number of different options, such as including (or not including) the current activity level:


Or, an analog watch face mode:


Or, a funky huge lettering mode (the mode is officially called “Big”):


In day to day watch mode the unit will get about 20 days of battery life (or 8 hours in GPS-on training mode).

Note that while you can invert the screen in the training mode (so it’s black lettering on white background), you cannot invert it for the daily watch mode, thus it’ll always be white lettering on black background in the non-training pages.

The unit contains a backlight that can be enabled by pressing the upper left button:


By default the backlight will shutoff after about 10 seconds, however while in an activity you can force it to stay on by holding the upper left button and selecting ‘Set Backlight On’.

Within the settings you can also change the default distance/pace/speed metrics used for the US/Imperial system (miles/pounds/ft) to Metric (kilometers/kilograms/centimeters):


Finally, you can enable a button lock from within the menu as well.

Data Fields:

As noted earlier you can customize data fields for the M400 through the website (not on the device itself).  In doing so you can create up to 8 pages of fields, with each page containing up to four pieces of information (metrics) on them:


Those fields are picked from a little object picker:


For the above data fields, on the M400 you can select the following:

Polar M400 Data Fields

Time FieldsEnvironment FieldsBody MeasurementDistanceSpeed/Pace Fields
Time of dayAltitudeHeart RateDistanceSpeed/Pace
DurationTotal AscentCaloriesLap DistanceAverage Speed/Pace
Lap timeCurrent Lap AscentAverage Heart RateLast Lap DistanceMaximum Speed/Pace
Last lap timeTotal DescentZonePointerLap Speed/Pace
Current Lap DescentMaximum Heart Rate
Time in Zone
HR Avg in Lap

Note however that for lap time, that’s only for manual laps, and not for auto laps.  Auto laps will show up online afterwards however.

In addition, you can add two further pages for ‘Back to start’, as well as ‘HR Zones’:


Once you’re done changing your data fields you can go ahead and save the settings and then sync your M400 either via USB or via Bluetooth Smart.  Both options will update the data fields on the unit itself.

Firmware Updates:


I want to very briefly point out that the M400 can and will get future firmware updates to both add features and get updates for bugs/changes.

The easiest method for updating is simply by plugging into your USB port and then loading the Flow Sync software which will then update the watch as seen above.

Polar plans to include free updates (like the running footpod), but may experiment down the road with being able to buy additional features for a small fee, such as purchasing the Training Load function normally found on the much more pricey Polar V800 (almost three times the cost).  They haven’t quite worked through the full logistics of this, but I actually think it’s a smart move long term.  It would allow folks to potentially pickup just the higher end features they want while in a budget GPS watch.

Again, Polar hasn’t quite nailed down any timelines or full pricing thoughts there – but that’s the rough direction they’re looking to go longer term with it.  Note that there are no plans to discontinue free firmware updates for things like bug fixes or minor feature tweaks/changes (and there are other unannounced major free features coming later this year).

3rd Party Support:


As of September 25th, 2014, Polar now supports exporting of workouts from Polar Flow.  This allows you to export out activities to either GPX or TCX files.  For most 3rd party sites that are sport-specific (i.e. Strava, Training Peaks, Sport Tracks), I’d go with .TCX, as it offers the broadest compatibility with sensor data.

To access the export function, you’ll go to an individual activity and then at the bottom of the activity you’ll see an export button:


Whack that button, which will then give you a menu option for the type of file to export to.  In this case for this example I happened to choose an indoor workout, hence why the GPX file option is grayed out (since it’s GPS based, which this file lacks).  So, it’s best here to choose TCX.


Finally, you’ll be given a TCX (or GPX) file downloaded to your computer:


You can then take this file and load it into a 3rd party application.  For the heck of it, I just selected SportTracks (online variant).


And then, seconds later…magic:


Now there does appear to be one limitation in that laps aren’t exported yet (that’s coming though, Polar has confirmed, hopefully later this year).

Finally, one other 3rd-party related limitation that doesn’t quite fit anywhere else in this post is that the ‘Fitness Test’ functionality within the Polar M400 will ONLY work with the Polar HR straps, specifically the H6/H7 straps. It will not work with 3rd party straps.  This is something that Polar has done to hard-code it to their straps only.  Obviously, this is fairly stupid and is just vendor lock-in for no real purpose (since all remaining M400 functions work just fine with any 3rd party straps).  On the bright side, I don’t find the Fitness Test functionality terribly useful in the grand scheme of things – so I don’t see it as a substantial loss.

Product Comparisons:

I’ve added the M400 to the Product Comparison Tool, which means you can mix and match it against any other watch/unit that I’ve ever reviewed for feature comparisons.

For the sake of simplicity, I’ve just selected the Polar M400, Polar V800, Suunto Ambit2 S, and Garmin FR220.  However, you can easily make your own chart with any device you want here at this link.

Function/FeaturePolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Copyright DC Rainmaker - Updated September 13th, 2018 @ 1:33 am New Window
Product Announcement DateSept 25th, 2014Jan 6th, 2014APR 29, 2013SEPT 16, 2013
Actual Availability/Shipping DateOctober 2014May 2014May 2013OCT 31, 2013
GPS Recording FunctionalityYesYesYesYes
WaterproofingYes - 30mYes - 30mYes - 50m50 Meters
Battery Life (GPS)8 hoursUp to 50 hours25 hours10 hours
Recording Interval1-second1sVariableSMART RECORDING (VARIABLE)
Quick Satellite ReceptionGreatGoodGreatGreat
Backlight GreatnessGreatGreatGreatGreat
Ability to download custom apps to unit/deviceNoNoYesNo
Acts as daily activity monitor (steps, etc...)YesYesNoNo
MusicPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Can control phone musicNoNo
Has music storage and playbackNoNo
Streaming ServicesNo
PaymentsPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Contactless-NFC PaymentsNo
ConnectivityPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Bluetooth Smart to Phone UploadingYesYesNoYes
Phone Notifications to unit (i.e. texts/calls/etc...)YesYesNoNo
Live Tracking (streaming location to website)NoNoNoYes
Group trackingNoNo
Emergency/SOS Message Notification (from watch to contacts)NoNoNoNo
Built-in cellular chip (no phone required)NoNoNoNo
CyclingPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Designed for cyclingYesYesYesBarely (Speed mode only)
Power Meter CapableNoYesYesNo
Power Meter Configuration/Calibration OptionsN/AYesYesN/A
Speed/Cadence Sensor CapableNoYesYesNo
Strava segments live on deviceNoYes
Crash detectionNoNo
RunningPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Designed for runningYesYesYesYes
Footpod Capable (For treadmills)YesYesYes (internal accelerometer)Yes (also has internal accelerometer)
Running Dynamics (vertical oscillation, ground contact time, etc...)NoNoNoNo
Running PowerWith extra sensor
VO2Max EstimationSortaYesYesNo
Race PredictorCan estimate finish time during raceYes, via Race PaceNoNo
Recovery AdvisorNo (only if you have V800 too)YesYesNo
Run/Walk ModeNoYes, via timersNoYes
SwimmingPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Designed for swimmingNoYesYesNo (protected though just fine)
Openwater swimming modeNoYesYesN/A
Lap/Indoor Distance TrackingN/AYesYesN/A
Record HR underwaterNoWith Certain Polar StrapsNoNo
Openwater Metrics (Stroke/etc.)N/AYesYesN/A
Indoor Metrics (Stroke/etc.)N/AYesYesN/A
Indoor Drill ModeN/ANoYesN/A
Indoor auto-pause featureN/AYesNoN/A
Change pool sizeN/AYesYesN/A
Indoor Min/Max Pool LengthsN/A20M/Y to 250 m/y15m/y to 1,200m/yN/A
Ability to customize data fieldsYesYesYesN/A
Can change yards to metersN/AYesYesN/A
Captures per length data - indoorsN/AYesYesN/A
Indoor AlertsN/AN/ANoN/A
TriathlonPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Designed for triathlonNoYesYesNo
Multisport modeNoYesYesNo
WorkoutsPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Create/Follow custom workoutsYesYesNoYes
On-unit interval FeatureYesYesBarelyYes
Training Calendar FunctionalityYesYesNoYes
FunctionsPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Auto Start/StopYesYesYesYes
Virtual Partner FeatureVia Race EstimatorYesNoNo
Virtual Racer FeatureNoNoNoNo
Records PR's - Personal Records (diff than history)YesNoNoYes
Day to day watch abilityYesYesYesYes
Hunting/Fishing/Ocean DataNoNoNoNo
Tidal Tables (Tide Information)NoNoNoNo
Jumpmaster mode (Parachuting)NoNoNoNo
Weather Display (live data)NoNoNoNo
NavigatePolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Follow GPS Track (Courses/Waypoints)NoYesYesNo
Markers/Waypoint DirectionNoYesYesNo
Routable/Visual Maps (like car GPS)NoNoNoNo
Back to startYesYesYes (added Aug 30, 2013)No
Impromptu Round Trip Route CreationNoNoNoNo
Download courses/routes from phone to unitNoYesNoNo
SensorsPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Altimeter TypeGPSBarometricGPSGPS
Compass TypeGPSMagneticMagneticN/A
Optical Heart Rate Sensor internallyNoNoNo
Heart Rate Strap CompatibleYesYesYesYes
ANT+ Heart Rate Strap CapableNoNoYesYes
ANT+ Speed/Cadence CapableNoNoYesNo
ANT+ Footpod CapableNoNoYesYes
ANT+ Power Meter CapableNoNoYesNo
ANT+ Weight Scale CapableNoNoNoNo
ANT+ Fitness Equipment (Gym)NoNoNoNo
ANT+ Lighting ControlNoNo
ANT+ Bike Radar IntegrationNoNo
ANT+ Trainer Control (FE-C)nONo
ANT+ Remote ControlNono (but can control GoPro)NoNo
ANT+ eBike CompatibilityNoNoNoNo
ANT+ Muscle Oxygen (i.e. Moxy/BSX)NoNo
ANT+ Gear Shifting (i.e. SRAM ETAP)NoNo
Shimano Di2 ShiftingNoNoNoNo
Bluetooth Smart HR Strap CapableYesYesNoNo
Bluetooth Smart Speed/Cadence CapableNoYesNoNo
Bluetooth Smart Footpod CapableYesYesNoNo
Bluetooth Smart Power Meter CapableNoYesNoNo
Temp Recording (internal sensor)NoYesNoNo
Temp Recording (external sensor)NoNoNoNo
SoftwarePolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
PC ApplicationPolar FlowsyncPolar Flowsync - Windows/MacMoveslink AgentGarmin Express
Web ApplicationPolar FlowPolar FlowMovescountGarmin Connect
Phone AppiOS/AndroidiOS/AndroidMovescountiOS/Android
Ability to Export SettingsNoNoYes (online)No
PurchasePolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Clever Training - Save with the VIP programLinkLinkLinkLink
DCRainmakerPolar M400Polar V800Suunto Ambit2 SGarmin Forerunner 220
Review LinkLinkLinkLinkLink

The tables are updated dynamically and thus if/when things change that’s represented automatically in this section.  And again, remember you can create your own charts easily here with any product you’d like.



Overall I’m really impressed with the M400.  Polar seems to have finally found an appropriate price for its products (some might even say they priced it a bit low actually).  The unit is a near perfect blend of activity tracker with GPS running watch, as well as daily wrist watch.

There are some minor nits I have, such as the lack of steps on the watch home screen itself.  And of course, it doesn’t do smartphone notifications (i.e. missed call alerts) like some of the other units on the market – though there’s no specific reason why Polar couldn’t add that down the road in a firmware update (I think they’ll be forced to competitively).

When it comes time to compare the watch, the major competitors here would be the Garmin FR220 and the TomTom Runner, and in both categories I’d probably give the edge to the M400. At least, assuming you don’t care about Live Tracking (Garmin FR220) or an indoor treadmill mode without a footpod (Garmin FR220/TomTom Runner) – I expand more on my FR220 vs M400 thoughts in this comment here.  Of course, I often note that neither indoor treadmill mode (sans-footpod) is terribly accurate, so that’s probably not a huge loss.  The Suunto Ambit2 S is also a very worthy competitor, but about $40 more expensive (the Ambit2 R is actually more expensive than the 2S, so silly to get that over the 2S).

At this point I’d have no problems recommending this watch, and the way things are trending I suspect this unit will easily make/top my updated 2014 budget/midrange GPS watch recommendations list for the updated winter season (November-ish).

[Update note April 15, 2015: Polar added the footpod support with firmware update 1.4. You’ll need to pickup a Polar Stride Sensor Bluetooth Smart for around $80, but this will give cadence and stride length metrics, as well as pace and distance when indoors on a treadmill.]

[Update note June 8, 2015: Polar announced Bluetooth Smart notifications for the M400 for iOS.]

[Update note October 22, 2015: Polar announced Bluetooth Smart notifications for the M400 for Android]

Found this review useful? Or just wanna save a bundle of cash? Here’s how:

Hopefully you found this review useful. At the end of the day, I’m an athlete just like you looking for the most detail possible on a new purchase – so my review is written from the standpoint of how I used the device. The reviews generally take a lot of hours to put together, so it’s a fair bit of work (and labor of love). As you probably noticed by looking below, I also take time to answer all the questions posted in the comments – and there’s quite a bit of detail in there as well.

I’ve partnered with Clever Training to offer all DC Rainmaker readers an exclusive 10% discount across the board on all products (except clearance items). You can pickup the Polar M400 below. Then receive 10% off of everything in your cart by adding code DCR10BTF at checkout. By doing so, you not only support the site (and all the work I do here) – but you also get a sweet discount. And, since this item is more than $75, you get free US shipping as well.

Polar M400 Black or White (with or without HR strap, select dropdown)

Thanks for reading! And as always, feel free to post comments or questions in the comments section below, I’ll be happy to try and answer them as quickly as possible.

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  1. Patrick

    Anyone else not having any luck getting this thing to pair and sync with phone/app?

    Android user with Note II and updated android software.

    I’ve found I need to delete pairings, restart phone, and even a few times uninstalling the app and re-installing got the watch and phone to pair/sync first try. Many sync attempts fail after the daily tracker data goes though (can see that update on screen).

    Very frustrating. Starting to wish I waited for the Vivoactive.

    • Alex

      Happens to me all the time, I actually gave up on the Android app… it just can’t seem to work reliably… (Nexus 5)
      Pretty frustrating, especially after waiting for months to have that feature… Ends up being half-assed and basically useless… I don’t even try to sync it via BT anymore and just plug in the damn cable…
      The guys at Polar don’t seem to like Android very much: last in date is the MyFitnessPal integration, only for iOS…
      I suppose if and when they roll out an Android version, it will be buggy as hell too…
      That being said, despite all these bugs, the watch usually does the job for the most basic (and essential) functions at a pretty decent price. I just stopped expecting any new functions beyond that…

    • Jerry Gonzalez

      I’ve had my M400 about a week now. Syncs with my Motorola Droid Turbo, no problems yet.

    • Tom

      I have had mine a week as well with Samsung S5 Synch all the time no issues what so ever. Not saying it may not go bad in the future but so far it works fine. The watch is comfortable on my wrist as an every day watch but I am sure after the newness wears off I’ll go back to not wearing any watch at all. The activity tracker is ok but I don’t really care one way or the other. In fact I wish you could disable it in polar flow and just keep the training sessions. Battery life I am a little concerned over. after first night full charge it dropped to 50% but it stayed that way for several days I am about 25% now. I have had an hours worth of GPS and HRM and 1.5 hours worth of HRM only. Figure every hour takes off 3 days of battery time if 24 days is the max battery life with no gps use. I am ok charging once a week. All in all a great first time GPS watch. I hope polar tweaks and peaks software…. I like the review run function in flow. Kind of fun to watch after a run.

  2. Horacio

    Hi DC Rain Maker, I’m thinking of buying a Polar M400 GPS as my first sport watch, the question is wheter to buy it with the HR strap u$ 195 or without it u$ 150. What do you suggest?. Is training with HR sensor more benefitial if it is only for running? Thanks a look foward to here for you.

    • runnershigh

      If you like I try to give you an answer. In general the polar watches (and software like flow) are extraordinary suitable for using HR-measuring for analysing your workouts (hf zones, training benefit and so on). If I would looking for a gps sports watch (especially for running) then I would choose the polar m400 if I prefer to do my workout using HR-measuring.
      If I don’t want to use HR-measuring then I would prefer another manufacturer like garmin 15 or garmin 220.

    • Horacio


    • Correct, the FR15 doesn’t have structured workouts. The FR220 does, as does the M400 (albeit to a slightly lesser degree). In general, I recommend the M400 over the FR220 these days.

    • runnershigh

      Indeed, with the FR15 you can’t send specific trainings from GC to the device. Otherwise the FR15 has some powerful features (virtual pacer) and it has a good price for that “package”. The FR220 is really comfortable to wear (like the FR15) and yes, you can upload your trainings to the watch. The m400 is not that comfortable to wear and not for everybodys (if small) wrist.
      If you are not suffering if you spend 55$ extraordinary, then I would take the FR220 without HR-Strap. If you need to save money then buy the m400 + HR-Strap.

    • Horacio

      My wrist size is 16.5 cm, you think I’m going to wear comfortable Polar m400?

    • Horacio

      thanks for replying, excellent review of the watch. In your regular training sessions running you wear Heart rate band? you usually echo on your heart rate zones?

    • Horacio

      Also wanted to add that I do not care monitoring daily activity and sleep and live monitoring or smartphone connectivity. The main use would give would be to train running either not going to use as an everyday watch. With this you can help me decide between the Polar m400 u$ 155 or Garmin FR220 u$ 250? if I can save money better. thanks for your advice

    • runnershigh

      my wrist size is app. 16cm and the polar m400 fits not really perfectly because of the large display part. I am allways using optical hr-monitor (mio).
      Because of your wrist size I suggest you to buy the FR220 without HR-Strap. HR-Monitoring is senseful if you run in hilly areas. Otherwise workout by pace is fully fine!

    • Horacio

      Finally I was given the garmin forerunner 10 there was the polar m400 and price with the Garmin FR220 had an important difference. Web or application that you recommend to create or continue training plan for 10 km, 21 km, 42 km based on pace and distance? to follow the garmin fr10. thx

    • Do note that the FR10 doesn’t permit downloading training plans though, only the FR220.

    • Horacio

      yes i know. but to follow a plan for each output before today I have to do 5 miles at a pace of 4:00 to 4:30 and there with information that gives me the fr10 I can go driving.

    • Paul Bunyar

      But would you recommend the FR15 over the M400? And why?

    • I’d recommend checking out today’s post…where the FR25 came out. Obviously it has less features than the M400, but different stokes for different folks: link to dcrainmaker.com

  3. Ravi

    Is it possible to set the watch window to real time calorie expenditure.It was possible in Ft7 , instead M400 shows the total calorie expenditure after training concluded.

    • Mike @ PolarUSA

      Ravi – It is indeed possible to see calorie expenditure during an exercise session. Simply log into your Flow profile, click on your name on the top right and then ‘sport profiles’. Here you can edit what you would like to appear on the watch face. – Mike @ Polar USA

  4. ray _ j _ n

    does Polar FlowSync software work with Windows Vista?

    • You can see on this page here if it’ll install: link to flow.polar.com

    • ray _ j _ n

      thanks Ray … that page stated that FlowSync does not support my operating system, which is Windows Vista … guess that means it won’t work with Windows Vista

    • ray _ j _ n

      … so can’t use the m400 with Windows Vista

    • runnershigh

      In general windows programs that run on Windows 7 also work under Windows Vista.
      Especially if it also works under Windows XP.

      Did you have tried to install FlowSync?
      If you feel unsure about that, then just take a recovery-point before installation, so are safe whatever will happens then.

    • Frans

      I can confirm that it works fine with both Windows Vista and Windows XP.

    • ray _ j _ n

      Thank you runnershigh and Frans.
      I have yet to bite the bullet and buy the m400, so haven’t tried to install FlowSync. It might install OK, but will there be any problems using it with Windows Vista?
      The m400 user manual, page 67, lists the compatible computer operating systems and shows Windows XP and Windows 7 but NOT Windows Vista.
      http://www.polar.com>Support>FlowSync>FAQs>What are the technical requirements for using Polar FlowSync software? … again the list of compatible operating systems shows Windows XP and Windows 7 but NOT Windows Vista.
      And on polar’s facebook page a post reads “my polar loop doesn’t sync anymore. my polar flow software doesn’t work anymore either. I tried to reinstall but I get the error that vista is not supported anymore. help!” … polar’s reply was “FlowSync is compatible with the following operating systems: Windows XP, Windows 7, Windows 8.”
      Can it definitely be confirmed that the m400 works fine with Windows Vista?
      Is anyone actually currently using the m400 with Windows Vista with no problems?
      Thanks, very much appreciated.

    • Frans

      I can reconfirm that M400 works fine with Windows Vista (dutch version).
      I’m using it to sync since I bought the M400 without problems.

  5. Claus

    Do you have information available if white strap is smaller – I also face issues that wrist size is only app 16,5 -17cm.

  6. Gokilu

    Do you know the range of wrist size?
    I need to know because my wrist size is 15.5cm


  7. Tom

    Is there a possibilty to set an interval: for example 1 km in 3.30-3.40.
    It seems you can only set the interval target as distance OR time, not the combination. I’m I correct?

    • Frans

      It is possible (I found information in forum http://www.chatnrun.nl).
      You need be sure that you have a PACE of 3-30-3.40 (polar flow: settings->sport profile->running-> speed/pace settings.
      Create a interval with distance 1KM, specifying PACE ZONES. Now change the up-down arrows to specify the required zone.

  8. Thomas

    Hi everyone,

    I have a problem with my new M400 and I wonder if anyone can give me a tip about what to do.

    The problem is GPS accuracy, and in particular measuring distance. I ran my standard 10km route (I am fairly certain it is almost exactly 10km) three times, exactly the same route. The watch measured the distance to be 10.04km, 8,86km, and 4.40km (!), respectively. When I run, both this and other routes, the watch sometimes beeps and says that it lost the GPS signal.

    Looking at the map in Polar Flow I can see that while the first recorded route is correct, the second maps the return leg (I double back) wrong to a close-by road. The third recorded route is just weird: it gives the wrong starting point and says that I used 34min for the first 1km.

    I am thinking that the latter problem might be explained by not having a good GPS fix when I started. Am I supposed to wait with running until the display says 100% (sorry I am a newbie with this)?

    But I am also worried about the more than 10% inaccuracy of the second recording. How can I trust the distance measurement on new routes?

    Any tips?

    • Magnus Helander

      The GPS almanac is live information about which satellites are broken and which ones are operational/reliable. This data is broadcasted from the GPS satellites at regular intervals and stored in your watch

      It takes 12.5 minutes for the almanac to download to your watch, and it is transmitted every 30 minutes.

      For your m400 to provide reliable tracking it must have this information. Still, Polar (and other manufacturers) does not want you to hang around for up to 30 minutes so they say “GPS OK” when in reality it is sometimes … sort of OK.

      I have not found a way to verify if the m400 has a valid almanac, but since you are concerned about GPS precision what you want to do is to set the m400 in Run mode with GPS on and keep it with GPS=OK for 30 minutes to be sure that the almanac is downloaded before starting workout.

      Especially after FW update or a reset this is critical.
      Read all about the Almanac here:
      link to en.wikipedia.org
      link to gpsworld.com

    • Thomas

      Magnus – that is very helpful. Thanks very much!

      What does the percentage in, e.g., “GPS 20%” exactly mean by the way?

    • It means it’s only 20% ready. Think of it like baking a turkey in the oven, if you took it at at 20% of the end-state temperature, people would get sick.

    • Grzeg1

      @Magnus I don’t know how you came up with 30 minutes (this could be ephemeris data validity period), but even wikipedia quoted by yourself literally says: almanac is transmitted repeatedly every 12.5 minutes link to en.wikipedia.org

  9. John

    I see that the M400 keeps track of how long you’re in a heart rate zone during a “session”. Does anyone know if the M400 keeps a cumulative weekly total (or longer) of how long you’ve spent in each heart rate zone? Either on the watch / web site / phone app? I would like to track how long I’ve been in a heart rate zone during a week (like I can with my FT60)… Thanks!

    • tom

      Yes it does in polar flow

    • Kale

      To be more specific, yes it does in the bottom of the ‘diary’ section of flow for daily, weekly, or monthly you can see your ‘zone’ numbers. It’s specifies a % and the actual time spent in each zone. It is very nice to have, I agree.

  10. Robert Black

    One little thing I’ve found yesterday is don’t leave the alarm clock enabled if you wake up early. I woke up an hour early and headed out for a run at 3am locking the backlight on. The alarm goes off at 4am. pressing the back button to turn it off also turned the light off. Go back into the menus to turn it back on and nothing happens. It’s off for the remainder of that session.

    Rather than stop I had to change my route to stay under the few streets that have dusk till dawn lighting. Most do not anymore.

    • Corina

      You, Sir, are a life savior! I’ve been having problems with my Polar m400 backlight, it kept turning off during training sessions, in spite of my setting it on ON at the beginning of the session. After reading you comment, I realized my alarm had gone off during each of these sessions and i turned it off. The backlight would also go off and i couldn’t turn it back on again. Thank you so much for sharing!

  11. Caspar Harmer

    I just wanted to say that my M400 has been working very well for me since Late December.
    I have noticed that the battery life may not be the 8 hours as advertised.
    My longest tracked activity (a canyon adventure run) was 5 hours and at the end of that, it said it had 10% battery life left. However that might be a measurement issue, as I’ve had it show 10% after 3 hours also.
    It does occasionally lose GPS connectivity in deep canyons and valleys, but generally this only occurs when you can see only 10-15% of the sky.
    However, all this is pretty much what you’d get from any GPS watch, as far as I can ascertain.

  12. John

    I’m wondering out loud… What would be better with a Polar H7 monitor, either (a) a Polar M400 or (b) iPhone 6 with Polar Beat (and training load when downloaded to PPT)? Each one has it’s advantages…

    • runnershigh

      If you like to take your smartphone to any training session with you, then you can keep your phone with you all the time. If not…

      By the way…”training load” means only to analyse your recovering time because of your “HR-Load”, but there are a lot of more body-functions that needs to be recovered as well.
      So, this feature truly shouldn’t make the difference.

      Keep going to the FLOW…

    • Tom

      Before I was using Endomondo on my smartphone. Since 5 days I’m using an M400 with HR.
      I love the M400 much more. U can u use it to train intervals, a lot more options, a lot easier to view the screen (my smartphone was in my pocket) and very important: the Polar M400 is a lot more accurate then my smartphone for GPS.

    • tom

      I was the same as you love having the watch over the phone. Now I am just trying to find a bluetooth small mp3 player shuffle sized.

    • Jason

      Tom, I bought one of these: link to gearbest.com and it’s worked great for me, especially for $21! I use it with Blueant Pump headphones. It’s a little quirky, but the audio quality good, and I almost never have any hiccups in the connection. The downshide is it ships from China, so it takes awhile. It also responds to the fwd/rwd/play/pause buttons on my headphones, so I just zip it into a pouch on my water bottle and forget about it.

  13. Mike

    Just as a confirmation:
    I am storing all my training data in garmin connect. I think since 2008. I am planning to buy the m400 or V800. I saw the export option on polars flow website. Is it working flawlessly to import it into garmin connect? thx

    • Patrick

      Yes, it works well. I also use an app on my Android phone called “SyncMyTracks” which makes it a little more automated.

    • Simon Anthes

      Or an app called RunGap if you’re on IOS – this can export from flow and import to Garmin Connect

  14. Jason L

    For anyone still thinking of this watch, here’s my thoughts after ~ 700 miles of running with it (and only running).


    1. The watch itself is very reliable. I have not had any problems with tracking (I live in Florida, though, so my GPS signal is probably a lot stronger than most).

    2. It works great with the Scosche Rhythm+ monitor. I’ve had problems with chafing using the chest straps, and the Scosche eliminates that problem.

    3. The on-watch features are pretty good, and pretty easy to use once you are used to them.


    1. The android app is pretty terrible. It “works” to get the data to Polar Flow, but it’s annoying and slow. A few examples of the annoyances:
    a. Even if Bluetooth is already on, it asks you EVERY TIME you open the app if it can turn bluetooth on.
    b. It insults me with a “It’s time to move” message, even after just getting back from a long run. It’s actually warning me about something that happened 8 hours ago.
    c. If you do anything with your phone — switch apps, make a call, etc., syncing will fail. The main app must be front-and-center, and I’ve even found that it’s less reliable if the screen turns off.

    2. Polar continues to be plagued by delays. This watch has been out for 7 months or so now, and there’s no footpod integration, no myfitnesspal integration, and a still-unreliable android app. If you go to Polar’s blog, half the messages are about how “we’re really sorry to say we have to delay…” or words to the effect.

    3. I’ve emailed support on a couple of occasions when a run didn’t sync (it shows up on my phone just fine with all the data) and I have never received a response. In other words, tech support is non-existent.

    4. I have had a few problems with the USB port and charging. Sometimes I have to really tweak the connection between the cable and the watch. It ultimately always works, but if you’re not paying attention you might go out for a run with a nearly-dead watch because it stopped charging a few seconds after you plugged it in.

    All that said, I’m still very happy with the watch. Despite the cons, it’s very good, it and it completely meets my needs, and I think an excellent value for the price. But it’s very nearly a *great* watch, and it’s frustrating to see Polar let the potential just sit there unrealized. I wish they’d pay more attention to the Android app. Given that the watch has been out for seven months, my concern is that Polar simply doesn’t have the required talent and/or staff to write a *good* app.

  15. nelos

    What about hrv r-r recording by m400???

  16. Jason L

    nelos, not sure if that was directed to me, but here’s my thoughts: the Fitness Test on the M400 seems to be a gimmick invented by the marketing department, not by any scientific data. The fact that there’s no explanation whatsoever about how it works I think is further evidence of this. As I’ve mentioned earlier, my fitness values have varied very little as my pace quickened and I lost weight over the last seven months. As far as I know that’s the only thing on the M400 that uses heart rate variability.

    If wouldn’t waste my money on it. The Scosche arm band is *much* more comfortable, and I actually find that it is more accurate than when I was using the chest strap.

    • Grzeg1

      Fitness Test is a marketing gimmick. It’s more or less like I can guess your height +/- 30 cm: it’s 170, isn’t it? Some of you will say it’s spot-on 😉
      Dont believe me? Ok, I was not completely true. Fitness Test is smarter. It will require you to enter your age, weight and weekly activity hours. So in our guessing game: you tell me what size you wear and how much you weigh, I will tell your height +/- 10 cm 😉
      Based on personal experience – FT only goes up when you move up weekly activity option and on reading of Polar’s test validity explanation.

  17. Simon

    Any one else had issues with the h7? I started with a 920xt but thought it was more than I needed, so returned it and got a M400. Very happy with what it does, except over 20% of my tracks experience spikes. Lots of them. I have tried new batteries, cotton shirts, no shirts, conductive jelly, saliva, water. It doesn’t matter I still get the spikes. It is really annoying to be training, and then suddenly get these spikes. It messes up the whole point of having this. Sometimes the spikes last for 5 to 10 minutes. Sometimes they settle, sometimes not. I never had a single issue with the 920xt and hrm-run.

    • Luka

      Nope, works flawlessly for me, haven’t seen a spike in >500km tracked in the past 3 months (running and MTB).

    • tom

      Could be a bad unit. I use the rhythm plus arm band with no issues. You should have those kinds of problems though.

    • Simon

      Yeah I wondered if it was bad, because I have read how great the h7 is, and that is not my experience. Here are some samples of what I am seeing, from bad to worse:

      link to flow.polar.com
      link to flow.polar.com
      link to flow.polar.com

      Its not always in the beginning like the traces above either. Sounds like maybe I need to get a replacement then.

    • Mike @ PolarUSA

      Simon – Have you tried cleaning the strap and contact points to which the sensor snaps to the strap? I ask as these straps needs basic maintenance and have found that if it is not followed, then erratic readings can appear. If the issue persists, give Polar a call at 800-227-1314 and a representative will help you further – Mike @ Polar USA

    • Marios

      @Mike @Polar. Any news on direct Strava integration?

    • Neil

      Looking forward to this feature too but only if it will ensure my activities appear as having taken place at the same time as those I ran/rode with. Currently the manual uploads do not match activities posted by those using other devices (mainly Garmin) and make it look like I ran at a different time to the reality.

    • Simon

      @Mike, I wash it under running water after every use as instructed in the manual. If there is some more specific way to clean it than just rinsing it I would like to know. I have been using the conductive gel as recommended on this site.

  18. Hank

    Mike or Ray,

    I am past my Amazon return phase and Polar Support says only the electronics are covered under the warranty so they cannot fix my problem.

    I am following all the advice to avoid rashes, but I am still having them with the M400 I purchased in Jan. It happens on both wrist and does not matter if I wear it so loose it will fall off.

    I actually love the device. I just want to see if something can be done to fix it. (I haven’t posted pictures on facebook or anything slamming the company fyi).

    Any thoughts?

    • Simon

      These might be a dumb ideas, but here they are anyway,

      a) I know you can buy liquid plastic in model shops. Perhaps if you coated the metal part on the back of the watch with this it would prevent the problem, though I am sure that would negatively affect warranty.
      b) perhaps a small band of thin material, say silk, kinda like a thin sweatband that would act as a barrier and not get in the way too much or be bulky under the watch would help?

  19. Hank

    For those with nickle allergies, support says the buckle does have nickle in it.

    Katherine: The buckle is made of stainless steel, unless you have a nickle allergy there would be a reason for a rash to develop. The comments in the page you’ve provided…many people make a note that they have a nickle allergy
    Hank Drew: Its actually not on the metal part near as I can tell…
    Hank Drew: mostly on the part that holds the strap down
    Hank Drew: I don’t have a nickle allergy as far as I can tell.
    Hank Drew: from what I hear the buckle does not have nickle anyway
    Hank Drew: in the same comments from “mike” at polar
    Katherine: Stainless steel does have traces of nickle

    • konradsa

      Interesting, I do have nickel allergy, but I don’t have any problems wearing the watch 24/7. I thought in this day and age nickel has been pretty much abandoned by all manufacturers in stuff that touches the skin. Sad to hear that this is not the case.

  20. Hank

    Yeah, I have never been known to have a nickel allergy, but who knows. So, after talking to them a second time, they are sending a replacement band. I have a feeling that if the same thing happens, I am going to be stuck with a paperweight.

    Because she was pretty strong in saying they would not support anything related to rash issues.

  21. Juan

    Hey Hank, I had the same issue when I first started wearing it. I developed something I thought was nickel allergy but after washing the back of the watch that touches the skin after working out and removing any sweat issues the problem seemed to fade away after about a week. Hope this helps.

  22. Steve Starr

    Question: One feature I love on my (still fully functional) Forerunner 305 is the feature that shows what your estimated next mile split will be based on your speed over the course of the current mile that you are running. VERY convenient when trying to run even splits on a run. Does the M400 have that feature?

    • frankis

      Yes, it does in a way. It’s called lap pace, but the problem is that it doesn’t have lap pace for automatically trigger laps (mile splits), you actaully have to push the lap button to start a new lap pace cycle, so you basically have to push the lap button everytime it autosplits.

      Even if you’re okay with this (which I am), the accuracy on the m400 is so bad that the number it reports is meaningless. I’m surprised that people aren’t having issues with the gps. I’ve run with the Garmin 405 and the Polar RC3 and now the m400 and the gps on the M400 is far worse than either of those watches. I’ve been running the same routes for the past 10 years and have measured them out on Google Earth and both the 405 and RC3 would trigger mile splits within about 10 -15 metres of where I would expect them. On the m400, I sometimes have to run an extra 40m before the thing triggers and this is over only 1 mile and yes I do give it plenty of time to acquire satellites at the start.

      I noticed that DC did not do his GPS comparison test where he runs the same route with two different GPS watches and then compares the distance reported, because if you did it with the M400, you would see that it terribly undermeasures distance.

    • runnershigh

      it’s complicated…about a 15KM competition my m400 shows me a bit more than 15KM but only 50-100m – so less than 1% difference. One training session I startet with m400 and FR110 as well the difference between them is that the FR110 counts a bit more distance as the m400. About 12-15KM distance may be 3% difference. I couldn’t say which device is right. Also in comparison with an iPhone the m400 auto-laps (1KM) are about 30m longer (3%).
      Usually after 200 metres on a new automatic lap the lap pace of a garmin forerunner is usefull. I would think this feature should’nt be worse if the m400 could do the same…

  23. runnershigh

    I am sruggling a bit with the 5 HR-Zones.
    Normally every Zone is set by Polar like Zone 5 = 100-90%, Zone 4 = 90-80%, Zone 3 = 80-70%, Zone 2 = 70-60% and Zone 1 = 60-50%.

    I like to change this setting (for running!) like this way: Zone 5 = 100-95% , Zone 4 = 95-90%, Zone 3 = 90-85%, Zone 2 = 85-75% and Zone 1 = 75-65%

    But if I do so, then my Zone for the “fast endurance run” is Zone 3. If that’s the case then the polar training benefit will give me wrong hints about my training.
    It would be nice if I can redefine which HF-Zone is for a specific training benefit.

    At the usual standard setting the hf zone 1 is useless (for running). My benefit would be optimized if I would set more zones within 5% ranges, but in my training diary I also like to have correct analyses….

    • asaf

      I had some similar thoughts about this issue…
      Training Benefits are most likely influenced by the way you define your HR zones… So basically, it’s up to the user to decide what’s the ‘benefit’… I think it’s also true for Strava and Suffer Score… You will never “suffer” if you define your lower Z4 as your Max HR…

      I also wonder how defining your HR Zones influences recovery prediction and calories consumption.

      Last thing- I really love the ‘stay in zone’ feature, but for it to be usable, I have to define my Z2 as higher and lower than it is to be able to stay in zone… (120-155) thus, adding noise to the Training Benefits calculations.
      I wish HR range alerts were independent of the HR Zones definitions.

    • runnershigh

      your solution could be if it was possible to change from 5 to only 3 HF-zones. Then the range of HR each zone would be bigger.

      Not my favorite scale because for me(!) there are between 80 to 100 percent of HFmax already 3 training zones.

      It seems to be a fact that there are for different aims specific zone-splittings beneficial/useful.

  24. Stefano

    Hy guy.
    is it possible to use m400 in the swim cap in the same way you suggest here

    link to dcrainmaker.com

    Thanks in advance

  25. Tom G

    Ray, had also left this comment on VivoaActive/Vivofit2 2 Review (no need to answer twice)

    After spending many days reading the reviews on this site (great reviews) had nearly decided to purchase 1st GPS running watch Polar M400. I know the VivoActive is more expensive – looks like it easier to wear daily (size). Does it offer a lot more for the dollars? I am mostly a runner. Should I stick with my original inclination for the Polar M400?

    • Browsing the Garmin forums can be a good idea before purchase link to forums.garmin.com

    • Tom G

      Thanks Magnus. Have just looked at the Garmin link and sounds like a number of people are having issues. Maybe I am just better off sticking with Polar M400 – from reading this detailed form here (1700 plus comments) most people are happy with the Polar M400 except for some GPS complaints (however even these seem to be addressed).

    • Apple did not have a fitness-device – they have one now with the Apple Watch.
      link to apple.com

      It seems to me Garmin is afraid of Apple eating their lunch so they are frantically innovating, releasing a number of new models and devices – but don’t allow time for testing and revisions instead releasing feature-rich but buggy beta-release devices. And that’s not a successful long-term strategy

  26. Lesley

    I have had my M400 since jan 2015 and been loving it, Tuesday 31 Mar my watch was unable to find that H7 sensor, nor the one I have had for sometime. Have done everything, deleted it and tried to repair, changed batteries, taken battery out and discharged the sensor. At my wits end – a hammer looks good!!
    Anyone else have a similar problem??

    Perhaps I need to get a Garmin – over brand loyalty

    • Magnus Helander

      One of three things are broken either (1) m400 Bluetooth interface, or (2) H7 sensor, or (3) HR-strap.
      First: Soft Reset m400 – press all four buttons (up/down/lap/light) until reboot. Now test…

      (1) Can the m400 connect to a smartphone/iphone over Bluetooth? “Pair New Device” in Bluetooth settings on smartphone and then pair the watch using the menu on watch. Does it work? Good – Bluetooth on m400 is OK. m400 talks to H7-sensor over Bluetooth, so watch is fine.

      (2) Put two wet fingers on contacts on H7 sensor (not belt), that will “start” the H7 – can the m400 find it now? Great – m400 is OK, H7 sensor is OK, the strap is broken.

      (3) You can also test the H7 monitor by connecting the H7 directly (pair it) with a smartphone to see if it works.

      “You can use your Polar heart rate monitor on Android, Blackberry (not BB10) and Windows Phone 8.1. Polar BTLE heart rate monitors can be used on iPhone 4S and newer as well. ”
      link to support.endomondo.com

      Also, test with a friends HR-strap (Garmin HR-straps actually work..) and then it should work.

      Good luck!

    • Lesley

      Thanks heaps for your reply
      I have done a soft reset – didn’t work!
      1) M400 syncs with my iphone

      2) m400 still didn’t find the H7

      3) H7 doesn’t pair with apps on my phone

      So it looks like the problem is with the H7! I have two H7s (long story) but neither are working – defies logic
      I have 3 straps – old wearlink sensor that is still working with my FT60 so straps are ok I think.

      I am running London on 26 April – doing training with HRM. Frustrating but I thank you heaps for your help
      Lesley NZ

    • Julian Middlewick

      Sounds a bit coincidental but I had exactly the same problem at the same time. The HR strap didn’t appear on the watch and there was no heart symbol on the watch itself. I don’t know whether this means it wasn’t trying to find the strap or whether it was just unable to connect to it.

      For me a new battery worked but it did take forever when I tried to re pair the HR strap with the watch. It took quite a few times and about half an hour of being told that it was unable to find any devices to pair before it eventually registered.

      I was just surprised that the initial battery didn’t last too long, 2 months roughly, although obviously I don’t know how old that battery was and how long it had been sitting on the shelf before I got it.

      I was also surprised that if it was just a battery issue with the HR strap that the watch didn’t show the heart symbol trying to connect to the strap, it just didn’t show it at all but maybe that’s a design issue and that’s just what happens when the battery runs down?

  27. MikeJ

    Might be old news to some, but I just saw this notice on the Polar Flow site:
    ===begin quote===
    “Team Polar Hello! Just wanted to let you know that we’re going to make some improvements to Polar Flow from April 15th 02:00 AM (GMT) onwards. You can’t use Flow during this time, but don’t worry, you can sync your data after the break is over at 09:00 AM (GMT). –Team Polar

    04/13/2015, 09:02 AM”
    === end quote===

  28. Steve Baldwin

    Afternoon all,
    I’ve had the watch for a couple of months now and overall I’m very happy with it. But I am finding that GPS lock is taking quite a lot longer to fix than I was expecting/hoping. I do live in Chicago so I recognize that getting a solid lock downtown in between the skyscrapers is nigh on impossible but I’m having to wait 7-8 minutes standing in a open area at the end of my street (where the average building is 2-3 levels high).
    Also through the run, the pace shown tends to fluctuate quite a bit (sometimes around 30 secs/mile) but the overall distance measured is generally within expectations which would tend to indicate lack of a solid gps lock. I reached out to Polar Support and they’ve suggested a factory reset which I will try but I’ve also read earlier posts regarding the almanac that needs to be downloaded as well. Polar support didn’t know anything regarding this though.
    Is this an essential component that I’m missing i.e. when I turned it on for the first time, I didn’t give it sufficient time to ‘calibrate’ and download the almanac? Is this a common complaint?
    Thanks for any tips/hints you have, very much appreciated.

    P.S. Anyone else desperate for footpod support? I do some indoor track speed work and can’t wait to analyse data from it.

    • konradsa

      Steve, Polar just released an update for the M400 that enabled A-GPS support. That should greatly help with your first fix time. Also, they added footpod support.

    • Steve Baldwin

      Thanks! Updated the watch and initially seems significantly quicker to lock on and the gps track (once outside of downtown Chicago) seems to much more accurate ie I’m now not cycling over Lake Michigan! Stride Sensor on order all ready!

  29. Stride sensor Bluetooth® Smart support. M400 is now compatible with Stride sensor Bluetooth® Smart and you can get a stride length and running cadence data for your runs.

    (link to polar.com)

    • Neil

      and they’ve hopefully fixed the activity export timing bug too so that exports to Strava should match up with reality now :o)

    • Neil

      I’m sure it’s already been answered in the negative already but will any other (smaller) pods now work (i.e. Adidas) for stride length purposes?

    • Rob

      I’m not expecting it to, but i will be able to answer this tomorrow morning if nobody else pipes up in the meantime. Today’s 5am run was this weeks hard effort, despite the enthusiasm to test it out today, I’m wasted.

    • konradsa

      It’s been a long time coming. A shame it took them until Spring to get this out to their customers, indoor running season is pretty much over here.

    • Robert Black

      posted my findings further on down the page, looks like i’ll be buying the humongous sensor next payday.

  30. JV

    Hi all,

    anyone know a good app or site where you can keep track the mileage on your running gear ? This is not possible within Polar Flow (and since I use different shoes, it is quite a chore to manually add up)



    • Dr. D

      @JV – I use the micoach app from Adidas. You can set up as many shoes as you like online at http://www.micoach.com then synchronize your app. Whenever you finish/add a workout, you select the shoe used. I carry my phone at all times, so I use the micoach app to track my workouts too.

      Good luck

  31. frankis

    I just checked out the new update 1.4.0 and THEY ADDED AUTOMATIC LAP PACE!! They added A-GPS as well so hopefully the GPS will be a bit better.

    • runnershigh

      I am really excited about this good news. I allredy have updated my device and reconfigured some profiles with auto-lap data fields. I will report in the next few days if it works like it should (as we know from some garmin devices in that case).

    • tom

      So what does auto lap data do nowrong that wasn’t done before?

  32. Patrick

    Two activities in a row. Mountain Biking and Hiking not showing a GPS track in Polar Flow when synced. Am I doing something wrong? Known issues? Thanks!

  33. Andreas

    I mostly run the trails but My trainer wants me to add sprints to My workouts.
    As i cannot sprint through bushes etc is There a way i can press a Buttenschøn to start a sprint and have.it show pace and distance and manuely stop the sprint to return to normal training view?

  34. Robert Black

    Okay been for my morning jog with the adidas speedcell and it’s not working properly. It loses pace and rpm every 70 seconds. Unless it’s designed to do that which I doubt? another thing is stride length average and maximum showed the same which would not be true, especially up the hills. anyway here’s the workout.
    link to flow.polar.com

    • JV

      Tested today with my new Polar Smart Stride footpod….pairing with the M400 went without a hitch, set for automatic calibration and the distance as measured by the pod was EXACTLY true (as measured once on the road with a tape roller). Nice to have cadence data as well now. Compared to the Garmin FR220 (which I had on the other wrist to compare) the cadence as measured by the Polar footpod is 10 rpm higher on average …..

    • konradsa

      When outdoors, I think it still uses the GPS to track distance, only the pace/cadence is coming from footpod then. Indoors, it should use the footpod for distance.

    • MikeJ

      I’m looking forward to the functional updates on the use of the footpod, first to see if it does use gps outdoors for distance when a footpod is active, second to see if it converts to the footpod if the gps signal is lost (like in a tunnel or heavy cover) and then goes back to gps tracking once reception is restored, third to see if the footpod calibration is accurate indoors if it was calibrated outdoors (treadmill or indoor running track).

    • JV

      You can actually choose:

      From the manual:

      When training with a stride sensor you can choose to use speeddata from GPS or from the stride sensor.To set this goto Settings> Sportprofiles> Running> Stridesensor > Choose sensor for speed,and choose Stridesensor or GPS.

    • konradsa

      True, but this doesn’t tell you whether the stride sensor or GPS is used to calculate the distance when running outdoors, it only talks about pace (“speed data”).

    • MikeJ

      I’ll probably have to wait until I get a speed sensor then, or wait until other experiment with it. I know I read in for of the other brand devices reviewed on the site here that that device would switch to using the footpod when the gps signal was lost, then switch back to gps once a signal was restored. From what you said, it appears that this M400 might be an either/or device and not a both device. But to avoid confusing others I’ll wait for more info.

      Also, I did not see an option for speed sensor on my flow.polar.com access, but it also might need me to add a speed sensor as an available device before those features show up. Probably be the same with setting the option on the watch itself directly and not using the Polar Flow site to update the sport profiles.

      Back to lurk mode until I get a huge speed sensor to strap onto my foot. Almost feel like I’d need two to stay in balance.

    • konradsa

      Haha, I got it and it’s actually not as bad as it looks. After a few minutes you will forget it’s there and never think about it again. It’s not an issue for running.

      The only time it has bothered me thus far is when you run in the gym and then you want to use some weight machines afterwards. If there is a cushion that rests on top of your foot, that could be a problem. In that case it’s probably best to bring another pair of shoes.

    • konradsa

      Ok, looks like both speed and distance are actually coming from footpod. I can make the distance go up just by standing in place and shaking my foot.

      I took it on a run this morning, and initially it seemed spot on, but my GPS measured 3 mile run ended up being short, around 2.95 miles. On the first mile, the footpod distance actually seemed ahead a little bit, but then on the last two miles it lost. Not much, but noticeable.

      So I think I have to redo the automatic calibration on a long straight stretch of my run, or maybe on a track, for it to get more precise.

  35. Pieter Oosthuizen

    My observations so far:

    – The export file time stamp has been fixed;
    – Custom laps totals now correct; (was accumulated prev)
    – Size bug on some export fixed.

    Did approx 10km with V1.4 last night, all fine 🙂

  36. LB2004

    Does anybody know if the stride sensor can be use at the same time as the HRM? If I’m not mistaken Bluetooth smart support only one connection at a time. On the other hand it would seem a ridiculous limitation having to choose between stride sensor and HRM.

    • konradsa

      No, they work simultaneously. There is a limitation that a device like the footpod can only be paired with a single watch at a time, but multiple different devices work with the watch simultaneously.

  37. Julian Middlewick

    I just thought I’d post on the thread to say thank you to Polar for the update as they do seem read and post here.

    It’s addressed 2 of the (relatively few) issues I’d had with the M400 with the automatic lap pace and the foot pod. Only automatic integration with 3rd party sites to go 😉

    All devices have some irritations hence me trying the M400 after using Garmins for a good number of years but overall it’s a very good watch which has just got better so thank you Polar.

  38. @ Mike@Polar,

    The information with autolap is great and also the footpod-support (have to fetch one tough).
    Still 2 major issues for me remain:

    – autoscroll, so that when running/cycling I don’t have to press buttons to see other information
    – when having created a workout, that the different steps are regarded as laps (especially when you choose ‘go to the next step automatically’), so if I create a workout like

    1. warm-up 2km
    2. 200m fast
    3. 300m pause
    repeat steps 2 and 3 10 times
    4. cooling-down (until I press the button)

    that this will result in 22 laps in my workout-data.

    One minor: warning beeps a few seconds before the next step starts.

    With these 3 things it will be, in my case, a full replacement of the FR 310XT (if the recording takes long enough 😉 ).

    Greetings, Dick

    • janosch


      Regarding Polar Germany the AutoLap Function for workouts – as you describe – will be integrated soon. They are working on it 🙂

      Best regards.

    • when having created a workout, that the different steps are regarded as laps (especially when you choose ‘go to the next step automatically

      Yes, that is what I most miss in Polar Flow. When doing a “phased” workout, I want to see all my phases in my analysis and the average pace per “lap”. In Garmin Connect I get to see those as laps, complete with average pace, maximum pace, distance, average cadence, maximum cadence, stride length and so forth. In Garmin Flow I get nothing of this at all. While I like the watch and the regular updates I feel that the software needs some work too.

    • //Correction:

      In Garmin Flow I get nothing of this at all.

      Of course I meant Polar Flow.

    • JL

      This is great news! That’s the main reason I’ve been hanging on to my RC3, as the old PPT website does show this information.

  39. “The A-GPS data updates once a day. The latest A-GPS data file is automatically updated to your M400 when you sync your M400 with the Flow web service via FlowSync software.”

    …that means no A-GPS data sync during a wireless sync. 🙁

    Source: link to polar.com

  40. Peter Scott

    Hi Ray, I am interested in purchasing the M400. Is it suitable for stand-up paddle boarding i.e. measuring distance paddled. If not could you recommend a GPS watch with activity tracking that is.

    • I think you can use it for any outdoor sports. Don’t know if it’s working well if you’re peddling (so your arms are moving forward and backward, but basically that’s almost the same when you’re running).. If you’re moving your arms ‘too much’ you could put the watch somewhere in the boat/canoe/whatever so it will track at least the distance.

    • It’ll work no problems paddling. Enjoy!

    • Luis Escovar

      Hi Ray, Did you meant only for voyage/travel distance and Speed (GPS), or did you also meant cadence (like when connecting to a VAAKA BLUETOOTH sensor for example).


  41. S

    Ok, here my observations regarding the footpod after running with it a few times:

    – The pace/distance both come from the footpod. There is an option available in the sport profiles that allows you to switch back to GPS for both. I assume then you only have cadence and stride length left from footpod.

    – Automatic calibrations doesn’t seem to work very well for me. When enabled, the watch tells you it will calibrate in 100m, but then it does’t tell you how long or how often it actually performs a calibration, and with what results. Then similar to what Ray has noted in his v800 review, I don’t seem to be able to get a correct calibration, and distances seem to be off. It seems to pretty much consistently clock me 0:20/mile too slow, and my distances are slightly too short too. Haven’t tried to manually correct the calibration yet.

    – Different calibration values seem to be available for each sport profile. So you can have a different calibrated value for indoor and outdoor running.

    – You can see the result of the calibration by selecting to manually calibrate, it will show you the previously acquired calibration factor.

    Overall, my excitement over the footpod has cooled a little bit. I think it will be most useful for people running indoors, or if you run in a really challenging GPS environment. But for regular outdoor running, as Ray already pointed out you are probably better off sticking with GPS for speed/distance. The footpad still gives you cadence and stride length then.

    • Thanks for sharing that. You said your excitement has cooled a bit but I find it quite encouraging. I live in a city and have not been too impressed with the GPS of the M400. I’d like a quick glance on my watch to check the pace. With a GPS you’ll never gonna know how much your watch is off. So I think a footpod for pace can be usefull for that.

      About the automatic calibration: I have never really understood why you’d want to use a GPS to calibrate a footpod. A footpod can be very accurate and after calibration very precise. My Garmin footpod was within 2% straight out of the box. Which can easily be improved upon by manually calibrating it against a known distance.
      An already sketchy GPS is not going to be much help in improving accuracy.

      I’d like to get a Bluetooth Smart footpod but the huge Polar stride sensor feels like a step back in time after using the tiny Garmin footpod for years. Robert Black tried the adidas speedcell and reported that it did not work well (comment #1732). I think I’ll wait and see if any alternatives show up.

    • konradsa

      Hi Andre,

      Regarding the calibration, I agree it’s best done on a track with known distance, I will probably try that too, but that requires a lot more effort. And your calibration will only be valid at that one speed. But I think it’s good that each profile seems to have it’s own calibration value, since I am pretty sure my stride on the treadmill will be different from my stride outdoors.

      I did try to auto calibrate it on a long piece of straight road with no GPS obstructions, looking at the map the accuracy of the GPS was great. I think it’s similar to the experience Ray had with the v800, where the automatic calibration is still off a little bit in the end. I wish they had the option of taking distance from GPS, but pace from footpod.

      But for challenging GPS environments, the footpod will definitely be the better choice. I still like having it for that, and also indoor running when the weather is bad. The size of the footpod is not really that much of a problem as people think. I was concerned about that initially too, but once you have it on your shoe it doesn’t bother and I didn’t notice it anymore. I would just give it a try, since it will probably give you best compatibility with the m400.

  42. Ben


    Is the M400 strap replaceable if broken ?


  43. karol

    Hi Guys!

    Maybe you can help me…
    Recently I have bought the polar M400 and Wahoo Run HR monitor.

    I am not able to pair M400 with the monitor. I tried yesterday (dry chest :)) and I have tried again today after my morning run (the whole running belt was sweaty). The same. The M400 doesn’t detect the Wahoo monitor. I got the following message (translating from my mother tongue): “put your device closer to your M400…connection was not successful”

    What is weird, the wahoo device works fine. I was able to pair it with my phone.
    What is even more weird, the bluetooth on M400 also seems to work. I was able to pair the watch with my phone.

    I have already contacted the wahoo service and I am waiting for their reply.
    Nevertheless, if you can give me any tips….


  44. Andreas Skjæmt Andersen

    After the upgrade my messages on the Flow website have not worked.
    It just keeps loading without result.

    This means i cannot accept the request from my trainer to access my sessions and plan for me.
    Polar Danmark is notified of this and have said it is a bug that is being worked on, but it is now 5 days since it happened.

    Is anyone else suffering from this??

  45. Gary Bower

    Hi – I have just had my first run with the Polar Stride Sensor and I agree with other posts in that it looks big in the box, but is not noticeable on the shoe.
    Hopefully it will resolve some of the GPS problems I have has with data drop-outs in long underpasses and heavily wooded areas; plus it will give me a basic idea of speed and distance whilst playing squash.
    My question is regarding calibration. I didn’t know how to calibrate it out of the box, so basically paired it with the watch (which was seamless), then ran. I did a 5k run which is exactly 5k (via accurate independent measurement), but my M400 always measures it slightly under at 3.04 miles rather than the full 3.1 miles. I presume that the stride sensor would calibrate according to the 3.04 miles on the watch because it automatically is set to ‘Automatically Calibrate’.
    However, after I synced my M400 after the run, I manually amended the distance from 3.04 to 3.1 on the profile for the run. When this change was saved, Polar Flow automatically recalculates the calculations for average min/mile, but can anyone confirm whether this would also amend the automatic calibration on the footpod based on the revised distance; or not. If it is the latter, thanks to the advice from earlier posts, I now know how to set it manually, so I guess I could run this course again with the setting for the stride sensor on manual and see if there’s a difference in the factor (which was automatically 1.042)?
    Thanks in advance for any advice; and thanks in general for the best and most honest feedback that is provided by the community using the DCR site!

    Thanks, Gary

    • Robert black

      As I understand it. Auto calibration takes two runs to settle in. The more you use it the better it should get. It will never beat a measured distance imho

  46. gasper

    Hi to everyone!

    Can you charge battery on M400 during workout?

  47. Robert

    How does phased pace settings work? I’ve set zone 2 to 12:08 > 11:48 mile and that’s sync fine on the watch so i can zone lock it for simple workouts. but on trying to create a complex workout in flow, zone 2 (light) shows 17:33 – 15:28 where is it getting that figure from? I walk as fast as that 🙁

    • Robert Black

      All is okay, despite what it shows on the flow website, it does transmit the correct settings to the watch. Had me worried for a minute, thinking I got to get another garmin. It’s a shame you can’t overlap zones as some of mine are only 20 seconds a mile faster in later training weeks and means rejigging the lot. They are my zones why cant I do what I like with them? It’s not just polar who do it in fairness to them.



  48. RIck

    A couple of nit picky items with the M400.

    1. You evidently have to use a Polar Chest Strap to perform the Fitness Test. But, you can use a different HRM for everything else.

    2. No distance shown inside without a footpod? Is this correct. Even the cheapest activity trackers give you their best effort to include a distance.

  49. RIck

    Thanks for the reply. Nice. Getting tired of looking at my MIO Fuse for an estimate, because my treadmill doesn’t show distance anymore due to a recent spill – haha.

    Everything else about the unit is great.

    Once my ship comes in the Fenix 3 will find a comfortable spot on my wrist.

  50. Judson

    Hey Ray,

    I recently purchased an M400 and I have been on numerous runs with the watch but the instant pace seems to jump wildly around from second to second. More than 2 min/mile from one second to the next. I updated the watch software as describe in the setup video and successfully sync’d the watch with polar flow sync. What do you think? Do I have a bum unit or am I just doing something wrong (none of my garmins have ever had this problem) Thanks for the help.

    • Definitely not normal. Plunk the unit outside for 20 minutes with the GPS on. Then see if that improves. If not, do a reset of the unit. Failing that, I’d ring up Polar support.

    • Judson

      Thanks for the quick reply Ray. I was just sitting with it scrolling through the menus and noticed under settings, sports profiles, running, stride sensor, choose sensor for speed – was set to stride sensor and not GPS. I’ve changed it to GPS and will give it another shot tomorrow. Do you think that may have been the issue (i don’t have the Polar BT Stride sensor)?

      On a separate but related note, do you think any BT stride sensor would work with the M400 or just the Polar sensor?

      Thanks again.

    • Robert

      The adidas one did’nt work properly for me, kept dropping the connection or resetting itself every 70 seconds. Polar one works a treat,

    • The adidas one did’nt work properly for me, kept dropping the connection or resetting itself every 70 seconds

      Strange, I saw the graph that you posted earlier. I wonder how that can happen, whether they crippled this on purpose or that it should work but just doesn’t?

    • Stephen Thomas

      The speed_cell has worked perfectly for me. Maybe your speed_cell battery is running low?

    • Judson

      Well, after four runs and pace (instant) jumping 2:30 min/mi every second I’m taking it back. Contacted Polar support and just got the standard “factory reset and resync” – didn’t work. Could just be a single bad unit but I’ve never had that problem with any Garmin I’ve owned. (610,305,301,fenix2). Also, I really don’t think there “break in” period for a GPS device. I mean – it either knows where you are or not and then for pace should look at distance over time for the last couple seconds. Not too complicated. I enjoyed ever feature of the watch but the wacky pace is a deal breaker. Back to Garmin I guess.

    • tom

      Probably a bad unit. It happens with every manufacturer. You should return it for another.yes even Garmin has bad units. I have 7sed it for 2 months now with no major issues.

    • @judson I used to be a “garmin guy” but have been running with m400 for about a year now. The m400 does provide a very smooth and useful “current pace” even without a footpod. Something is wrong with your unit and you should have it replaced.

    • Judson

      Finally got it figured out. The M400 was seeing my Wahoo HRM Run as both a HRM and a stride sensor. And since there is really no way to turn off the sensors with the M400 it was kind of no bueno.

  51. gasper

    Thanks for the reply mr. Boris!

  52. Steve


    Thanks for the awesome reviews! I can’t believe how thorough you are! I’m an avid runner and I’m really struggling to decide between buying the TomTom Runner Cardio ($245) or buying the Polar m400 and the Scosche Rythym + separately (together about $200 on sale).

    I like the idea of having the HRM right on the watch, but it might not be all that necessary. I also tend to think that Polar’s training log is a little better, and the customizability of the training screens on the m400 is a huge plus.

    Do you have a recommendation between the two? Runner Cardio vs. m400 w/ Scosche Rythym?


  53. Grace

    Can someone tell me if the ‘ Estimator mode’ is a unique thing for the M400? So that a watch tells you the time you are about to finish with the distance set based on the pace you walk?

    I was wondering if a Garmin or Tomtom watch has got something like this as well (Note: Watch must be in the same price range)

    • I can’t tell for the Tomtom, but at least my Garmin 310xt hasn’t this function. It has the virtual partner and you can use that. If you want to say f.e. finish a 10k in 50 minutes, you choose as pace 5’/km and then Garmin will tell you how many seconds/metres you are ahead or behind of that schema, so if you see after 2km that you’re 10 seconds ahead of it, you can calculate that if you will run at the same speed (of you will go again to 5’/km) that you will finish within 50 minutes. 😉

    • David

      The Garmin 920XT does have this feature.
      Training->Set a Target
      Then you have options:
      Distance Only – Shows you estimated finish time based on elapsed time and current pace
      Distance and Time – As above but also shows time/distance ahead/behind target time
      Distance and Pace – As above, but entering a target pace instead of target time

    • David

      Sorry, I missed the part where you said in the same price range. It’s possible the Vivoactive has the same feature. But I can only speak to the 920XT for certain.

  54. gasper

    Does anyone experience problems… when synchronizing M400 to my computer my time settings on watch goes back for 1h and daily activity goes 5% downwards..!? What is wrong?

  55. gasper

    i am sorry, i solved the problem!

  56. dd

    Anyone using custom cut screen protector for this device?

    I saw two different on amazon – Savvies and Vikuiti brand. Any recommendation? Thanks

  57. guavajuice

    Is the GPS and bluetooth always on unless i put it on flight mode?

    • Bluetooth only active in “pairing mode” or during workout.
      GPS receiver is active only during an workout which has a sport profile with GPS tracking.
      I think the “fligh tmode” is a safety lock to make sure that you do not accidentally activate the BT Radio by starting a workout, which makes the m400 start looking for HR belt and foot pod.

  58. Tom G

    I have opportunity to buy M400 + HRM $210 or V800 + HRM $396 in Australia. If I am mainly running is it worth the extra spend for the V800?

    • konradsa

      For a runner, I don’t think so. The strength of the v800 is multi sports, swimming and biking. The only reason to get the v800 is the better GPS chip, but paying twice for that is not worth it. The v800 also has other issues that the m400 doesn’t have, like charging connection clip going bad quickly and moisture getting inside the watch easily.

    • Andreas

      Absolutely not.

      I come from the v800 and unless you need HR while in water I see no bomus to buying it.
      M400 works like a charm and is a killer for the price.

    • Stephen Thomas

      If you do a lot of trail running, the V800 has a barometric altimeter, which is significantly more accurate than the GPS-based altitude that the M400 reports. Otherwise, for a runner, I don’t see any advantage to the V800.

  59. Joao Simoes

    it is not possible to turn off the watch like garmin 15 ?

  60. Andreas Andersen

    Is anyone else experiencing serious problems with Flow since their upgrade?

    I cannot see my messages and therefore accepting my coach to view and plan sessions for me.
    It keeps loading forever without result but shows a green sign over the map saying HTMLobject something.

  61. Michael

    Hi Love your reviews! very detailed and logical. I am interested if this watch can be set up to do interval sprints? i would like to set the distance to 150m with 30sec rests but can find nowhere what the minimum distance setting for the interval timer is?

    • Simon

      The on watch interval timer allows you to do in .1 km intervals. However setting up a training target on the website seems to allow a bit more control.
      Negative to doing it that way (which I really don’t understand), is that interval timer on watch actually records a lap when the interval changes, but using a pre-programmed workout does not record laps for the changes. I find it mystifying..

    • Laramie

      I totally agree. It’s a nice watch with a lot of features. But the inability to see your lap data after completing a custom workout is kind of ridiculous. It would almost be better without custom workouts. At least then I wouldn’t have gone to the trouble of setting up a workout for virtually no reason. Oh well, maybe lap data for custom workouts will be added in an update.

  62. Tom G

    Ray thankyou for your great reviews – I have spent so many hours (I have driven my wife mad) reading about all the alternative gps watches.

    Unfortunately as I live in Austyralia I could not purchase from Clever Training – with shipping and conversion of US$ to Aust$ it was going to cost too much. I wish there was another way I could pay for your site – a subscription/donation of some sort would be great.

    Thankyou to all the people who have helped me on making my final decision on the Polar M400, my first GPS watch – there were so many alternatives and it was hard to make a decision (Konradsa, Andreas, stephen Thomas, and Magnus).

    Can’t wait for the watch to be delivered.

  63. Steve Baldwin

    Good morning,
    Hoping to enlist some advice. Went for a reasonable length run yesterday morning (around 10 miles) but couldn’t locate the H7 signal at all before setting . Footpod was recognized but not the heart rate. Other than that, the watch operated normally though the was run in fairly heavy rain. When I got back I tried to sync it with my iphone but after taking an abnormally long time to sync, it showed no activity since last syncing ie losing all data from the run (arrrrgggghhhh!!!!). It also has lost the watch settings that I normally have stored, for instance it shows my name rather than the daily activity bar. I’ve tried the 4 button watch reset to no avail.
    A little concerned, I connected it to the computer via USB but had an error message from FlowSync saying that connection was lost (like when you get when the plug isn’t in properly) so I can now not update A-GPS files and more importantly conduct a factory reset. This has continued.
    It being the weekend, I’m waiting to speak to Polar Support on Monday, though this is sounding a little terminal if I can’t access the factory reset feature. But in the meantime I’m running the battery down to see if that works, but I wanted to ask if anyone else has had similar problems?
    I’m not hopeful. It’s a great watch especially with the H7 and stride sensor but these kind of problems take the shine off a little.
    Sadly this reveals how much I’ve come to rely on data to define whether it was a good run or not…..
    Thanks for any comments,

  64. John Bowman

    Been using the M400 for about two weeks now and for the most part I am fairly pleased except for a few quirks. The most recent is battery life with the backlight on. Just wondering if anyone else has experienced similar. I was excited to find the “keep backlight on” setting because the default timing wasn’t as long as I would prefer, but after a 1hr 40min run with my wife this morning, my watch was at 10% life when I got home. I started my run at 100%. I should have turned it off during the run, but honestly just forgot and it is a little cumbersome to do as it is a multi-step process.

    I normally take my long runs with my wife in the early mornings and it is not uncommon for us to be on the road for an hour- hour 30min before the sun comes up. We also live in a town with very few street lights. Is this the battery life I should expect with the backlight on? Wouldn’t be as big of a deal if I could trigger a 30sec or minute backlight with a button press.

  65. runnershigh

    I have a little problem by syncing my activity profiles (running, cycling e.g.). Since the latest firmware update I started using two new datafields (autolap pace, autolap average hf). Both datafields sometimes get lost in flow after syncing with the m400 device. So I have to configure my activty profiles in flow again and trigger the sync again…this happend three or four times until now and it gets on my nervs.
    My impression is that after syncing of new trainings the activity profiles in flow will be corrupted but I see no senseful reason for that.
    Any ideas? Thanks.

  66. chaplanger

    When using the automatic lap function what are the minimum distances that can be set? Can you select 1/4 miles (as you can in Garmin FR205)?

    • frankis

      On the watch itself, you can only set it to 0.1 mile increments. If you do it through the website, you can set it to 0.25 miles. I’m not sure if you can set the autolap in the polar flow app.

  67. john

    I just wonder whether this device can remote control the SPOTIFY music player? Please advice.

  68. hrishi

    Is it possible to get underwater HR by pairing M400 with Mio Link, with M400 being in a non-swimming profile? (Stefan in V800 comments mentioned you can change sports profile later in the Flow website)

  69. Simon

    Will the M400 work with other brand footpods, or the tickr-run? All I really want is cadence information.

  70. The M400 works with the Adidas speed_cell. It shows cadence on the watch and in Polar Flow.
    Stride length shows as 0 in your analysis though.

    You can choose if you want to use the stride sensor or the GPS for speed from the Quick Menu. (whereas if you have the Polar Stirde Sensor you’ll also find the settings under settings>sport profiles>running). From here you can also start an automatic calibration or set the calibration factor manually if you wish.

  71. Rick

    Tip: don’t leave back to start as an activity field. Use it manually through the light button. Otherwise it drains the battery pretty quickly.

  72. AndiT

    Does anyone do rowing on a machine here? I just started doing it as part of my cross training regiments, but it’s not listed in the Sport Profiles. It has rowing, but that’s for rowing outside, it wants to hook up to the GPS.

    Shall I just use that? Or any other suggestions?

    • michal

      I think you could use ‘other indoor’. Im going to test it for indoor rowing this week.

    • AndiT


      I found a way to disable the GPS for rowing, so now it should be ok. I will try it out today or tomorrow.

  73. runnershigh

    The Sport Profiles are only suggestions/templates. You can choose any sport profile and turn off/on the GPS measuring as you want. The specific name of the sport profile is not the point.

  74. Grace

    Is there a way to turn the watch completely off when turned on? How?

  75. Sebastian

    I bought the M400 a couple of weeks ago, used it once then returned it.

    I think the watch itself is solid enough and its GPS tracked slightly better than my iPhone 5s. The UI of the watch wasn’t great (layout and flow of the screens, the presence of the activity tracking bar for example) but it was at least better than the absolute shambles of the website (or should I say multiple Polar websites). I know there is talk of integration with strava etc which would be welcome but for me the overall UX currently offered is a total let down.

    I will revisit dedicated GPS watches in future but for now I’m going to go with the Magellan Echo, my iPhone 5s and iSmoothrun as my tracking combo with uploads to Strava. iSmoothrun really is the usability standard to which Polar needs to aspire (as well as offering data uploads to other websites).

    • michal

      I cant tell anything about the website and your needs. It suits me very well. And there is possible to change the layout of screen as well as the look of time display.

  76. JV

    Well, after two months the m400 died (usb port rusted). Watch couldn’t charge or sync anymore. Despite my initial misgivings that this did happen after such a short time, I have to say, Polar Netherlands was very quick in repairs. (Turnaround 1 day !). Fingers crossed it does not happen again.

  77. So I was just about hitting the trigger on the Vivoactive, but the so-called “Smart recording” put’s me off. Im using my current Garmin 305 for both my runs and kitesurfing, and since kitesurfing is was faster than my running 4 second recordings are absolutely junk (I get that it measures every second, but I need to export to endomondo which renderes the every second measurement useless anyway).

    Now I’m trying to find out if the M400 does in fact support 1-second record rate or not? I can see that in the comparison chart 🙁


  78. Tom G

    Have just purchased the M400 + HRM, and have now gone on 2 runs. GPS is working well, and over a 10km run, distance was nearly exactly the same as a Tom Tom Cardio Run that I had borrowed (maybe 10m out).

    Also as a daily watch – it is not too big, so I will wear for activity tracker and sleep analyses, which is a bonus.

    A couple of questions I have – if someone can assist it would be appreciated:

    (1) I am not sure if I set the watch up properly for automatic stopping when I stop running at traffic lights. Is there something I can do to check. How do you set watch for this?

    (2) I did not purchase a foot pod. For an average runner do you think this will assist for out door running – do not use treadmills. I am considering purchasing if information it provides is valuable/can help me improve my running..

  79. art

    I recently sold my FR 220 and bought the M400. Initial reactions: Thanks Ray for the recommendation!

    After two days of running on mountain trails mostly tree lined:

    1) Accuracy:, I found that for every 10 miles that I ran, the GPS was off between one and two tenths of a mile.

    2) Satellites: I took me under 5 seconds the first run and about 15 seconds the second run to get 100%

    .3) Watch: Having 4 lines of display is awesome, as is being able to see see the pace zones and hr zones at any give point. Also, the instant pace worked well and showed increments of 1 BPM The only disadvantage I found was that there is no way to see recovery heart rate. (has anyone found a workaround?)

    4) Bluetooth: no problems syncing to my android phone.

    • Hi Art

      Can I kindly ask you to try to export a file from a run (As long as you might have it) and upload it to some other service (Endomondo/strava/Myfitnesspal).

      And see if the data matches up?

      I’m just about to pull the trigger, but I really need to be sure it’s 1-s recording and not something “smart” like Garmin does 🙂

      Thanks a lot!


    • Magnus Helander

      Hi Morten, it’s 1s tracking and 1s GPX data export, here is a GPX rendered in gpsvisualizer link to files.helander.fastmail.fm

  80. Oh just read in the manual of the M400 it says sample rate 1S – will it then be safe to assume the actual recorded data exported also is 1S? 🙂


    • Magnus Helander

      I use GPSvisualizer.com a lot and by activating “Show Waypoints” it will draw the individual samples.

      Here is a GPS-file exported from Polar Flow and rendered in gpsvisualizer
      link to files.helander.fastmail.fm

      The export is “every second” as well, which is good news.

  81. Kara

    So I need to get a new bike computer (thinking Edge 810) and run watch (thinking Polar M400). I am loyal Garmin user! But I had the FR10 (when 1st came out) and GPS never picked up on a few occasions so thinking M400 would be good?

    Really want to know how well it would pick up heart rate coming out of a triathlon after the swim.

    Anyone know? Thanks in advance!!

    • The M400 is a good running watch but honestly a poor triathlon watch. If that’s your focus, I’d look at the Ambit2S as really the best bang for the buck there.

  82. Julien

    I’m using a Kettler indoor bike, which shows average heart rate via sensor. Is there a way that I can manually input that heart rate data into flow-polar, under my “Indoor Bike” training sessions?? Without adding that data, my “indoor bike” training sessions data (eg Calories) doesn’t relate to anything realistic.. Thank you. Julien

  83. Katie

    I have a question. I have had my polar m400 watch for 2 days. It’s been working fine, then all of a sudden before my workout tonight a message popped up on the screen that says: something went wrong. Press OK to reset m400. I pressed the ok button and that won’t do anything. I’ve pressed all the other buttons and nothing will work nor will this screen go away. I tried to plug it into the computer to see if I could sync or or reset it that way and nothing works. Any ideas? I tried contacting polar, but of course they are closed. I wasn’t sure if you had heard of this coming up before. Please let me know. Thanks

    • tom

      I hate it when things don’t work right. the only other thing you could try is a soft reset push the up arrow down arrow and light but all the same time and hold it for a bit. if that doesn’t work it looks like you’re going to have to wait until the battery dies. I would be prepared though to return the watch and get another.

    • Katie

      Tom thank you so much for the comment! I tried the soft reset by pressing the 3 buttons and unfortunately that didn’t work. Also the battery is at 100% so I’m going to contact polar tomorrow and hopefully they will send me a new one

    • tom

      you are very welcome I went back to the polar website again and it looks like you’re really disposed to push all the buttons at once. although in your situation I’m guessing it’s probably not going to work. just so you know I’ve had my watch for about 2 months now with no major problems whatsoever. did you get it from Clever Training? they have an easy 60 day return policy. once it gets working I am guessing you will enjoy the watch.
      You can do a soft reset by pressing and holding the UP, DOWN, BACK and LIGHT buttons simultaneously for five seconds until the Polar animation is shown on the display. After the reset, the M400 automatically goes to time view.

    • Katie

      Thanks again! I did the 4 button reset and that worked! It erased all my data for the day but I’m fine with that as long as it works. Hoping it doesn’t happen again. I actually got it off eBay but I think polar will replace any of their products no matter where you got it. I had an issue with my strap on and old model and they sent me a new one

    • I had the same “something went wrong” problem/error message after I did the latest firmware update. Polar advised a factory reset, that solved it and the problem did not come back.
      So I think you should be OK now.

    • tom

      Happy to help have fun!

  84. Marcos Buosi

    Hey everbody, I have a question, but first of all, let me tell that I’m not an English native speaker, so I’m sorry in advance for any mistakes 🙂
    I have a M400, and everything is working pretty fine, the watch is really great!! The only issue I’m facing is with an specific activity I made last week. When I check the activity on the iPhone app, I can see all the details, like map, laps, HR, pace, etc. The problem is that when I check the same activity on the web app (Polar Flow), I can only see the total distance, time and avg HR. No details at all!! I’ve tried to sync the watch with the computer several times, and also with the phone, but the details are not transferred to the web. What is even stranger is that other activities completed after that one, synced with no problem.
    Have you ever experienced this issue?
    Thanks for the support!

    • Mark Hughes

      I’ve had this problem once – what you need to do is make a “change” to the activity in the app (for example, enter something in the “how did it feel” box) – this should cause the activity to be resynced with the online service and the rest of your data should then show up online.

      Hope that helps!

    • Marcos Buosi

      It worked!! Thanks!!

    • Chris

      I had this problem today too, the solution worked for as well. Thanks @Mark

    • Mark Hughes

      Glad to be a help, it took me quite a lot of trial and error when it happened to me a while back!

  85. Riaan

    Do you note the FW versions when you do the tests?

    I have the M400, FW 1.4.0 , and also got the Wahoo TICKR Run FW 1.6.25, and I cannot get them to BT pair with one another.

    • I do sometimes cover firmware if there’s reason to believe something might be impacted by that (either because it is an issue already, or something of that nature).

      Unfortunately Bluetooth sensor compatibility across the board is a continual issue, however for the most part the simple HR part appears to work for most companies.

      Any chance you have an app still open on the phone that’s holding the connection?

    • Martin

      I was able to pair my M400 with a Wahoo Tickr X – no idea about f/w versions though. One thing I will say is that the wahoo app likes to hang onto the connection, esp. the iOS version. I had to disable bluetooth on my ipad a couple of times to get the Tickr X visible to other devices.

    • Riaan

      Sorry for the late reply, but I had to wait till I could get some testing done at the local Polar support centre.

      No, No mobile phone apps are holding any BT LE port open.

      It seems as if it is a problem in the M400 latest FW1.4.0
      Tested the Wahoo TICKR Run/X, and Scoshe Rhythm+ units on 3 different M400’s at the Polar support centre, as well as a V800 and V650 cycling computer.
      They all worked fine on the V800 / V650, and on one M400, that has an older Firmware(1.3.x) on it. None worked on the 2 x M400’s with FW 1.4.0
      It may work on 1.4.0 if the HRM was paired whilst the unit had a FW of 1.3.x, but the chances are slim to pair something new with FW 1.4.0.

      So now we wait(maybe in vain) for the next FW version to come out, where they will hopefully fix this.
      Maybe I should go and buy the Garmin FR225, and scrap the Polar.

    • Riaan

      Hi. Just an update after the FW on the M400 was updated to 1.5.15.
      I can now pair the M400 to both the Wahoo Tickr X and Scosche Rhythm+

    • Christoph

      I updated to 1.5.16 before I tried to pair it with my Wahoo TICKR and I could never get it to find the TICKR (full battery, works perfectly with other devices, BT turned off on all other devices when trying to pair)
      Anybody else having these issues?

    • Christoph

      *M400 Firmware 1.6.4,

    • Christoph

      UPDATE: As there was no way to downgrade, I returned the watched for a new M400 with 1.3.2 firmware. Paired it to the TICKR without a hitch and then upgraded it to 1.6.4. It’s still paired. Thanks Riaan!

  86. Art

    The last update for the M400 was in late March (Stride Support.) In terms of the next update, I have read a number of different things: Recovery (for a fee), Swimming functionality, Smart Notifications, etc.
    Does anyone know when the next update is planned to be released and what it will provide?

    • Alex

      Don’t know, but also looking forward to these upgrades:
      – internal accelerometer cadence detection (would love to use this to improve running form without shelling out 70€ for the stride sensor…)
      – third party integration FOR ANDROID
      – cycling cadence sensor (but sadly I know it’s definitely not on the list…not sure why though…)
      – some sort of triathlon mode? (for example a preset swim/T1/bike/T2/run sequence that require a single press between each leg, or at least easy switching throughout the different sport profiles as you race instead of manually launching independant sessions or using a single “outdoor” chunk)

      In the meantime, I’m looking for an Android app that can measure cadence from a phone accelerometer for my next run: Does anyone use this sort of app? Does it work well? Which app would you recommend?

  87. Niek

    Training Load/Recovery would be nice!

    I have a question about the stride sensor for my M400. I read that you can select this stride sensor for speed/distance info (and thus this data will not be come from GPS-data). Does this mean that in this case when I synchronize with Polar Flow, I don’t see my (GPS-based)route on Polar Flow?

  88. @Niek: You can still see your route in Polar Flow.

    • Niek


      Thank you for the quick repsonse!

      So, to be sure; The distance and pace information (as well on the watch during the run, as on Polar Flow after syncing) is based on the stride sensor and just the route is based on the GPS-file? Or is the distance and (average) pace shown in Flow based on the GPS-route?

      (I hope you can follow my question :-))

  89. Yes, speed information is based on the stride sensor if you choose that from the settings on the watch: “Use stride sensor for speed”. You can also use GPS if you prefer that (ans still see your cadence).

    Not sure how Polar Flow calculates the pace and distance though.

    • konradsa

      Looks like pace and distance is coming from footpod, while the actual path is coming from GPS. So if your footpod calibration is off, the actual distance and distance indicated on the path will not match.

  90. MikeJ

    H7 battery level: the instructions for the Polar H7 state that the battery level should display on a receiving device, so does the M400 display the H7 battery level somehow? If so then maybe I just don’t see it, or maybe it is a setting via the Polar Flow site. I might be doing a 4+ hour activity tomorrow or Sunday and don’t want the HRM to die mid-activity (cycling or golfing, haven’t decided yet).
    Thanks for any info.

    • konradsa

      You can check it via the Polar Beat iPhone app, that’s the only way I know. M400 definitely doesn’t display the battery level.

    • MikeJ

      Okay, thanks, kind of what I figured but wanted to verify that I wasn’t missing something. Thanks again for the quick reply.

  91. Manolis

    Hello, i just bought 2 M400 with HR belts included. One for me and one for a friend. We Followed the instructions by the book in order to pair the HR with the watch, with NO LUCK!!! I Updated the software, the firmware with the same result. Both watches fails to even “see” the HR Belts!!!

    Any idea about what is wrong?


    • Alex

      Have you by any chance paired the HR sensors to an app on your phone, just to check they worked?
      You can only be paired with one device at a time so you’ll have to kill any active connection before you can pair the HR sensor with the M400.

    • Neil

      Don’t know about Polar but often such products have a little piece of plastic (with a tiny visible tab) to stop the button battery connecting and discharging while in storage. Maybe check and see if that’s the case and remove the tab as necessary to power the belts up?

    • kevin

      Are you attaching sensor to strap and putting on before pairing? You can also wet two fingers and hold them on the sensor connectors to turn it on before pairing.

    • Riaan

      I don’t have the same problem, in as much as my H7 HRM strap works, and pairs immediately. However, I cannot get any of the Wahoo straps to work. Tried both the Run, and the X versions. They both work and pairs to various apps on various phone’s but no way will the M400 sees any of them.

      Yes, I made sure that no phone app kept the BT connection open. Put all my other units into the MW oven, as a shield. Those that I couldn’t, I switched off, and left in another room. Switched off my Wi-Fi, so no 2,4GHz frequencies closeby, and still nothing. The M400 refuses to see any of the two Wahoo units.

      Removing the H7 HRM pairing, removing the battery, and resetting the M400 to factory setting also does nothing. After a restore, and then repairing the H7 HRM, is immediate, so I don’t know what can be the issue. It is as if the M400 doesn’t like 3rd Party HRM’s.

      But as mentioned by the other answers, remember that the HRM only “switches on”, as soon as the connection is made with the strap itself (the two clips is connected), and the unit is “wetted” and put against your body for a heartbeat to appear. It will switch off, after it doesn’t see any heartbeat again, after a set time.

  92. cheerio

    Anyone tried the watch with swimming? My first time yesterday, and I was surprised that I burned a mere 143 kcal in 1 hour! Is this normal or could there be something on the watch I didn’t set for better accuracy?

  93. ps

    I love my M400 which is about 4 weeks old but I had to return to Polar due to some very strange behavior with the USB port. The watch rapidly connects/disconnects, sometimes showing charge complete, as shown in this video (not my own) link to youtube.com
    Eventually the watch would sat change complete but not actually charge at all.

    I also experienced strange syncing behavior and possible USB condition similar to this
    link to forum.slowtwitch.com

    Does anyone know the root cause of these issues? Was there a large group with problematic USBs? Or is the USB design inherently flawed? I really like flow and the data I receive. I want to stay in Polar ecosystem but I am worried. My watch has been well cared for. I just hope I get a working unit back soon for my training.

    • John

      Yes, I experienced this same thing. I tried a different cable, and each time the new cable worked for a few times, then stopped working. I sent the watch and original cable back to Polar. It worked twice when I got it back, then stopped working again. I believe they only sent back a new cable — I don’t think they did anything with the USB port, even though I explained the behavior. I again sent the watch and cable back to Polar this week.

    • ps

      Thank you so much John. Let me know how things work out with Polar. I will also share my outcomes. It sounds like this may include many users.

    • Chris P

      I am afraid I am on the same train with this problem. I started yesterday I was about to synchronize my watch before a morning’s training. It seems that either port is of poor quality or cable. I used to have similar issue with phone. At some point I could not charge it without holding the cable inside the USB port, that was HTC ONE SV – htc support confirmed it’s common issue with USB port quality. That would be a shame if the same would have happened to my M400, I bought it just one month ago. It is a fabulous watch, but that would be serious flaw if USB got broken.

    • LB2004

      I believe it is very dependent on the micro usb cable you use. I had more than a few cables available but only the polar cable and some old nokia cable (from Symbian era) seem to work. Other cable don’t work for connection (but at least one of those work for charging if connected to a usb charger).

    • Yes, I agree with LB2004
      We have plenty of micro USB cables lying around the house. So I did not unpack the cable that came with the M400 in the box. I had problems syncing, I could feel that the cable did not fit properly. I changed the cable with the original cable and the problem went away.

    • ps

      From what I am finding out there are some with cable issues only, and others with cable and port issues. I tried multiple USB cables and had the same problems with the USB port.

    • John K

      I have experienced similar problems. I had the USB cable replaced, but after 5 months of use it appears the USB port failed (used multiple USB cords, none would charge the unit). It has been sent back to Polar under warranty.

    • John

      I just got my watch (and cable) back from Polar. The diagnosis was: “C10 – Oxidation in Connector”. It worked perfectly the one time that I’ve tried it. The test will be if it works over several days.

      – I don’t know if Polar sent me a new cable, or the returned the one I sent in with the watch. The cable is listed as a $7 line item on the return, so I’m guessing it was a new one.
      – I wonder if there is a way to prevent oxidation, or clean it myself if it happens again.
      – There was no charge. I paid to ship it in (USPS Priority Small Box Flat Rate). Polar paid for the repair and return 2-day shipping (which I selected when I submitted the repair order — $15).

    • ps

      Did your USB port look like this? link to forum.slowtwitch.com

      Just curious to see if we can make a link. My watch is still being serviced, but I do remember it not looking completely shiny. I am a happy V800 owner. I really wish I would have bought a V800 to begin with.

  94. Chris P

    Something to cheer up. Latest update of Android Polar Flow brought new features:

    – A-GPS is now synced through BT too
    – battery level
    – For V800 ‘users can now get power graphics and swimming metrics via Flow app’
    – Polar Flow is now compatible with Google Fit

  95. ps

    Unfortunately this was my solution to the M400 USB problem:

    1. Training for a marathon that is very important to me. Family needs will take me away from this oportunity coming up in June.
    2. I did not want to be without a device
    3. Therefore I purchased a V800 shipping overnight so I don’t lose weekend training data.

    I will give my repaired unit to a family member as an activity monitor only. Not sure how the Polar warranty experience will go, but I just do not want to wait for this to play out.

    • ps

      I should have said family needs after June will make subsequent events more difficult to train for. I know that my race in June is a window of opportunity I have to take while healthy and with time for some training.

  96. Tom G

    Have watch for 3 weeks, It has exceeded my expectations.
    GPS works well, and quick. Have improved distance and speed.
    I am in an office job, and Activity Monitor has been great – motivates me to get up and walk throughout the day, and after work on non running nights.
    I wear when sleeping as well, and this is helping me understand how much sleep I need every night to feel rested next day. I loosen wrist band for comfort.
    Only downside is I have over trained – and have taken the week off to let sore ankle to recover.

  97. Dave Kirkpatrick

    Hi Ray – Do you know when Polar is planning the firmware update for the M400 that will include notifications?

  98. -running-

    Does anybody know the difference between
    HR Avg in Lap
    Lap HR avg
    both can be selected , the “Lap HR avg” is new in menu … but I can not get what it is – or should it be like “last lap hr avg” ?

  99. AndiT

    For the last two training sessions I had problems with syncing. It would take ages for the watch to sync and after about 3-4 minutes I would get a message on FlowSync saying that there was a problem and I should try again. I tried again, same thing. However, when I logged in to the Flow website my workouts were synced, no problem.

    The watch also charges ok, so no problems there. Has anyone experienced something like this?

    • Chris P

      Yes I did. When I was synchronizing my watch through BT, watch was displaying ‘Sync Failed’. I tried couple times, I restarted the app on my phone. It did not help, but it seemed he uploaded all data (at least training record). After this incident I have issue with GPS, watch was losing GPS sygnal (which never was the case – an open terrain). Eventually I had to stop training and start again, it helped. I don’t know if those glitches are associated together. I guess it may have been, I did not have anything like then before Android Polar Flow update.

  100. elb

    Well apparently the M400 thinks that my Wahoo Tickr Run is not only a HRM but a footpod as well. Unfortunately, it no longer displays pace correctly. It will show the pace bouncing all over the place if the source for speed is the stride sensor. If the source is set as gps, you just get zeros. Firmware 1.4.0

  101. Arnold

    How do you turn off the Polar M400? I couldn’t be more puzzled

  102. You can’t. Like a watch, it is always on.

  103. Alex


    Looking for help on a workaround, any help appreciated:
    I would like to use the Polar H7 HR with my phone and M400 at the same time.
    Just like at the gym, where I can see the HR on both the watch and the polar compatible workout machines.
    This doesn’t seem to work with phone and watch: whichever device grabs the connection first gets to use it exclusively…
    I tried ticking the “allow HR to be viewable by other devices” (or whatever the proper translation is) in the HR menu of the sport profile, to no avail… Am I missing something?

    Now my question is:
    If I use the phone as H7 receiver, is there any way to rebroadcast the H7 signal from the phone to other devices using some sort of app on the phone? And then manage to connect from the M400 to that emulated “BTLE HR”? (I don’t care if I loose running index or other proprietary stuff, just plain HR is fine)


    • Riaan

      Not currently, as far as I know.
      Also, the Gym equipment you use, uses the Polar H7 analogue 5KHz signal, and not the BTLE signal, hence why they are working both at the same time.

      If you read a lot of the comments (also for some of the other devices), you will see that there are some apps/devices, that rebroadcast ANT+ to BTLE etc, or the other way around.

      I am sitting in the same situation, and decided to move to a dual ANT+ / BTLE HRM. BTLE for the M400, and ANT+ for the phone. However, it seems as if the only app currently (on android), that accepts the ANT+ signal, is the Wahoo app.
      Runkeeper and others all want the BTLE signal, and as you say, whichever between the apps, and the M400 grabs the signal first, will keep it.
      My problem is again that the M400 has a newer FW, and doesn’t want to pair to any other HRM, except the Polar H7. So I still end up running with 2 x HRM’s.
      At least both can be BTLE, or BTLE and ANT+
      Hope this helps a bit

    • Alex

      Thanks for the info Riaan.
      I actually use the wahoo app too, connected to the wahoo Blue SC speed/cadence sensor (which is dual BTLE/ANT+), but i’d like to grab the HR at the same time. And still have the M400+HR work alone for the running portions of my triathlon brick training (my phone being attached to the bike). I was contemplating switching from H7 to a dual ANT+/BTLE HR (either wahoo or some other third party) as a backup plan, but from what you say I’ll hold back for awhile…
      On a side note, I find the wahoo app to be very nice: simple, reliable and can be configured to easily export to many platforms. (still waiting for Polar’s MFP/android integration…)
      I can also just stop one device and launch the other between each brick but it’s kind of a pita…

  104. Scott

    Bought the M400 on a trial period and really liked it. Unfortunately there were a few deal breakers for me and I ended up returning it. Here are my brief thoughts.

    1. Different activity modes. I bike to work and it was nice to have a record of how far I bike on top of my running.
    2. Activity tracker. Although I found that on the days I run (am before kids are up) I hit my goal before heading off to work, and the days I didn’t run I maybe broke 50% of my goal.
    3. One watch. Running, everyday, activity tracker.

    Liked (but probably the same with other brands)
    1. Online training log with maps, heart rate, pace, etc. I had an old forerunner 405 with no ANT+ stick and didn’t know what I was missing until I started researching for a new watch.
    2. Heart Rate Monitor: much more comfortable than the old Garmin that I haven’t used in years because it just wasn’t comfortable.

    Didn’t like
    1. Had to hold completely still for the GPS to pick up. If I was hooking up the stroller to my bike or getting the kids situated it still wouldn’t connect (but probably not uncommon to other GPS watches)
    2. Having trouble connecting it to computer. Something with the USB chord was having trouble registering the watch the last couple of days I had it.

    Deal breakers
    1. Too big for my little wrist. (I am 6′ but my wrists are the same as my wife who is 5’1″). It “fit” my wrist, but aesthetically the watch was just too big to be worn as an every day watch and looked big and clunky.
    2. No stop watch/timer outside of activity tracker. Since this is expected to be used every day as an activity tracker, it would be nice to have an option for a basic stop watch or timer for those non-activity type needs. However, I feel that this is lacking on any GPS watch out there. For a watch just to be used on runs, no big deal, but it seems like this would be easy and helpful for GPS watches that second as an everyday watch.
    3. Pressure on straps make it feel like they won’t last long term. Taking off the watch always caused a lot of torque on the main strap and the rubber flap over USB port doesn’t feel like it will last. Call my cynical, but I would expect that little flap to be broken within 6 months to a year.

    Unfortunately this leaves me back to square one. Maybe I am expecting too much in a single watch. I thought the M400 would best meet my needs. Currently I am looking at the FR15 (activity tracker, women’s size aka smaller, and basic running) but I would upgrade to a nicer HR monitor. Or the FR220 but that doesn’t have the activity tracker which was nice to have. Unfortunately neither really lets me track other activities like biking as the M400 did.

    • runnershigh

      FR225 is inclusive activity tracker. Forget the activity tracking and took the FR220.
      I allready have the m400 since november last year and I agree with your dealbreaker point one.
      After 4 months I stopped using the watch as a activity tracker and just for running/cycling I think I can handle the size/fitness. That’s it.

  105. Tom Torvik

    So yesterday 12 miles in to my long run I had the “Something went wrong reset M400” message. My question is has anyone else had this issue? Was it a common occurrence? I reset on the run lost all data started another session and it worked. Today I did a factory reset….. I am hoping this does not happen during my marathon…… I wonder what caused it…..


    • Alex

      Happened to me twice, once on a basic training run, another time about 15 miles in a 40-mile bike ride during my vacations in netherlands… First one I didn’t care too much, second time I was a bit disappointed… Restarted a new session and it worked OK for the rest of the bike run. It was a bit cool/humid that morning but not sure if this has anything to do with the problem. I would be very pissed if it happened again during a special event though…

    • Happened to me all the time after the firmware update to 1.4
      A factory reset solved the problem, never happened again.

    • Brian Peterson

      I have had several issues with my first watch. I had Sent it in to polar and the end result was being sent a replacement watch. I hadn’t had any issues with the new watch until 20 miles into my marathon when the watch displayed “Something went wrong reset M400” or something very similar. So far since then I haven’t had any issues.

      I am very happy with the watch and the functions that are supposed to work. When there is an issue with performance and things do not work as they should it is very disappointing.

      I will continue to use the watch though for now and if I start to have problems again I will go back to my rock solid Ironman stop watch. I know my pace enough to be able to estimate mileage. Not ideal but until they solve the performance issues it my be the best option for me now.

    • Tom Torvik

      Yeah you know I get electronics need to get reset every once in awhile but you are right during a long run or special event if that happens it will be a real bummer. If it fails it should remember where it was at last and at least save the session….. This is my first GPS watch so this was why I was asking. Most of the time it’s been working great.

    • Nigel deutrom

      Happened to me ona number of occassions. ..2nd time i sent it back as it wouldn’t reset at all…polar did something with it not sure what and it came back working. ..3 weeks later and its happened again…unable to reset at all…plug in to pc nothing so its gone back again. I have asked for a new watch as this is getting tiresome

    • Nigel deutrom

      Common occurrence for me..happend a few times…last time it wouldnt reset so i sent back for a 2nd time and polar gave me a new watch…fingers crossed it doesnt happen again

    • John

      Happened to me twice on one bike ride, and today a third time.
      The first time I could re-set—but every synchronization thereafter notes that “there is a problem” and lists the two times it railed an was re-set.
      After today’s third time. it will not re-set using any sequence of buttons; will not sychronize; and messages to Polar support return an acknowledgment that “we are very busy at this time…. etc.”
      So, I think this will become a hood ornament unless I get lucky.

  106. John K

    The micro USB port on my M400 went bad after about 5 months of use. While I like using a standard cable, I’m concerned about the durability of the USB port. I commend Polar customer service – they replaced both the USB cable and repaired the watch under warranty, but wonder how long I can expect the watch to remain fully functional. Polar recommended that I insure the port is dry before inserting the cable, but I’m not sure how they expect a user to do this.

    Also, I have little confidence in the altitude – I run out and back, and find that the elevation difference between the start and end can vary by as much as 60 feet.

    Any thoughts/comments?

    • ps

      I received my m400 back from Polar service. They replaced the USB port on the watch and included a new cable however I have already moved on to the V800 and could not be happier. Personally I do not have a great deal of confidence in the m400 interface, but others have not had issues and maybe it could have been different for me. It definitely appears as if enough of these cases have popped up to make someone concerned.

    • Hans

      Same here: usb port went bad after four months, it’s at the retailer now, should be repaired within two weeks.

  107. Tim

    So I went on an interval training with my M400.

    I did 500m fast – 500m slow, 5 times:

    link to flow.polar.com

    I’m disappointed. The first 3 intervals, it shows pretty clear that my speed 13-14km/u is not picked up from the beginning of each 500m, but only about halfway (even though i was running the shit out of myself from the beginning).
    My old garmin watch had no troubles picking up the changed pace. Do any of you has similar findings? Is there somewhere a setting in my watch where this can be modified?

    • Greg

      I noticed the same thing during my interval trainings, it takes long time to update pace, and it is pretty annoying… I made a test with my “old” Polar RC3 and it is clearly quicker…

  108. Niels

    Does anyone know if there is a software like the V800 downloader for the V800?
    It is tiresome to export every single training from flow and load it to Strava.
    Thank you

    • KilkennY

      You could Use syncmytracks for Android or the Rungab app for IOS.
      I use Rungab and it takes just a few clicks on the phone, and my activity has been shared to Runkeeper, Strava, Endomondo, health, Facebook Etc.

      Kind regards

  109. alex

    I just randomly checked for the updates on M400 and found out that the smart notifications are available under IOS!

    link to updates.polar.com

  110. WPI

    Does anyone know if you have the ability to charge the watch during an activity without interrupting the recording? For example, If I were participating in an 18 hour bike race would I be able to connect an external USB battery charger and toss it into my jersey and let it charge while it is still recording progress?

    • alex

      It is working for me, I started activity, waited a bit, then plugged in into power bank via USB and charged for a while and pugged out again. After that I stopped the activity and just to be 100 % sure exported into polar flow, everything seemed to be ok

  111. Kevin

    Has there been any date for the cadence and distance from the watch update? Trying to decide if I should buy the Pilar stride sensor or wait for watch update, thanks.

    • konradsa

      If you need distance, just buy the foot pod, since I doubt distance will be very accurate just from the watch. If you just need cadence, I would probably wait.

  112. Randy Cantu

    So glad that M400 notifications are available now!

  113. gokilu

    So happy with this update for M400.
    It works great 🙂

  114. Juan

    Hello everyone! Very happy with the watch..purchased it earlier this year. I just have one issue. I saw that there was a new iOS update for the watch with smartphone notifications and I plugged in the watch and it saying that the connection can’t be established when I connect it to my Mac but it’s charging so I don’t think it’s an issue with the cable (using the one that came with it) or the port. Anyone have any ideas what could be causing it to not sync with Polar Flow?

  115. Unhappy polar user

    Unhappy Polar User
    Jun 09 – 5:05 pm
    Has anyone had any issues with the M400 ?
    I’ve had to return mine three times to polar
    1St return .in April my watch stopped recording after 39 km during my first marathon even though it was fully charged time was 3:40 polar said it was a firmware issue and sent me back the watch
    2nd return:Mid May watch failed to charge polar refuse to change the watch and add a new component
    3rd return :Watch won’t sync to polar sync tried several cables and in installed the program still no joy..drop the watch off at dealer and ask him to plead my case guess what?? Polar still refuse to change the unit and promise for the third time to fix the unit…Its on the way to polar and there’s still a discussion to be had but really is this common practice??
    Surely a unit like this should go to scrap and the customer should be compensated??

    Watch is 6 months old and has spent 4 weeks in repair this is not including the third time BTW

  116. Juan

    Hi! I cannot get my m400 to sync to FlowSync to save my life. I’ve checked all ports, connections, firewalls, tried the usb that was sent with the unit along with two others. It will show that the m400 is charging but continues to say, “Connection to Polar product lost….” What am I missing? Thanks!

    • LB2004

      I had a similar problem yesterday with my wife’s Polar Loop. It was not recognized while connected to a external non powered usb hub (windows reported a non recognized peripheral, so apparently a usb driver issue). It was correctly recognized when attached to a mainboard port. If changing port didn’t help, I would try a usb hub and then trying uninstall and reinstalling polar flow software.

    • Magnus Helander

      Mac/PC? Flowsync properly Installed? Other USB devices working? Tried all available USB ports? Disconnected all other USB devices?

    • Juan

      Magnus, thanks for the reply. I have a Mac running OS X Yosemite. FlowSync seems to be properly installed and other USB devices were working and I only have 2 USB ports and both were working and didn’t have anything else plugged in while trying to sync. I was just confused because the cables were charging the watch but it wasn’t syncing but as you can see below I found some luck on the 4th cable. Thanks again!

  117. It still could be the cable. I know you tried that but I found myself on several occasions that this connection is problematic. We have a bunch of those micro USB cables here in the house and most give the same error: “not connected”or similar wording. I have one cable though (from my Wacom Bamboo tablet) that works fine, since I knaow that I only use this cable.

  118. Bryan J Trinque

    Same issue with my Mac yesterday. Charging but not syncing. Different cable solved it. If it happens again try a third cable.

  119. Juan

    Thanks for the replies everyone!! It’s been greatly appreciated. I went had and tried a 3rd and 4th cable and it worked on the fourth cable so maybe the cable does matter. I will have to keep this one safe since it’s the only one that syncs with my M400. Polar just replied this morning and wanted me to send my watch to the NY repair center so good think I checked on here before sending it off.

  120. Juan

    I also think FlowSync is having issues because after I updated my watch it went back to saying connection lost and it just closed itself several times. Not sure if Polar is having issues and not saying anything.

  121. Kara

    I do lots of work out videos at home (insanity, yoga, a variety), occasional hikes, and short runs utilizing intervals. I am wanting to make sure I am making the most of these times with monitoring heart rate would this be a good watch for me? I am a small female, worried it will be enormous on me and that it just may be overkill. But the price isn’t much higher than some of the less feature rich options so was considering it. Any advice?

    • Tim

      Hi kara, if you want heart rate monitoring this is a good watch. If you do intervals with running and need accurate speed, this watch fails, then go to Garmin.

    • Why can’t you do intervals on it? Many people do just fine.

    • Tim

      I posted it a few posts before with links to my workout. If you do like 500m high speed intervals, it only picks up the correct speed at about 250m. I’d like to see my effective pace from when I start the interval, now it builds up slowly to be correct only halfway. I never had this with my garmin.

      Maybe something you should include in your tests, a short interval run to measure pace accuracy.

    • Yeah, I do lots of interval workouts all the time and didn’t see that last fall – perhaps something has changed.

      I poked the Polar Forums, and only see a single other person seeing the same. Have you considered contacting Polar support? Something doesn’t sound right.

    • LB2004

      I have the same problem. I do short intervals and speed takes a while to update. It’s as if it is an average of the speed of the last 30 seconds. It’s not a terrible problem but it’s there.

    • Tim

      For me personally that’s a serious issue. That’s one of the reasons I wear a GPS watch, to record exactly what I’m doing, especially when doing intervals.

      @DC Rainmaiker: I haven’t, but I’ll give it a go and let you know what they said.

    • The other item to try is a reset of the unit. I don’t remember off-hand what the method/key buttons is for the M400, but in general that usually solves GPS lag/etc type issues (for example, especially on Garmin units).

    • I noticed that too. For getting the pace of a short (20-30 second) stride, the watch is too slow/inaccurate, just what you want to call it. As LB2004 points out, you are basicly looking at a moving average. If you want to have accurate pace at any moment during your intervals you’ll need to get a footpod. It is a shame that the Polar footpod is such an enormous thing, and that the much smaller Adidas speed_cell cannot be calibrated with the M400.

    • Heath

      I believe it is a common problem just that not many users notice it since they do not look at the pace immediately when starting off a 400m interval lap. But this problem is definitely there at least for me. But at least mine start average out correctly at the 100m mark but there will be times it average out near 200m mark.

      M400 is using per second pace like the v800 so could it be due to chipset accuracy issue?
      Garmin, as far as I know are at 5 seconds interval unless they have changed it so it won’t be good for short interval immediate pacing.

      As Andre pointed out, footpod is the way to go but based on Ray comment on Polar footpod with the v800, not sure if it is the best idea.

    • Really no watch is good for doing 100m sprints. For 200m sprints you can do it more or less just fine as long as it’s in a straight line.

      But honestly you really shouldn’t use GPS for those types of workouts. Simply mark off 100m (or whatever set distance you want), and just focus on time past given points (i.e. a rock/tree branch, etc…).

      As for 5s increments, there’s no perfect solution. You’re going to get smoothed data one way or another (whether or not you realize it). So either the data is smoothed heavily to get 1s increments, or it’s smoothed into 5s buckets.

      That said, you can very easily get 1s data with the lap average, which is perfectly suitable for interval pacing. I often do 400m and 800m ones on that easily down to odd-numbered seconds – like 6:22 per set.

  122. Tim Reddy

    I have been having all the same cable issues. Syncing over USB works for a couple weeks, then it becomes intermittent, and then stops working at all. I’ve swapped between 4 different cables, all of which work for other devices. I sent back to polar, the said that they repaired it. Came back working fine for 3 weeks, then all of the same problems started again. I’m about to send back again.

    I don’t know if they are shipping terrible cables, or if the port is failing on the watch. Like I said, the cables work fine for kindles and other devices, so I don’t think it is the cables. Unless there is a problem with the watch design that is breaking the cables? Hard to imagine.

    Seems other are having the exact same issue. I wish I could get my money back.

    • Sim YS

      I guessed the problem is due to oxidation of the female USB port. The USB port can easily trap the water or sweat within the gaps and that will cause the connectors to oxidised.

  123. dd

    For all you out there with USB connection problems make sure to follow the official manual recommendations about caring for your product. Especially part 4 and 5.

    1. You can wash the device with a mild soap and water solution under running water. Do not use alcohol or any abrasive material such as steel wool or cleaning chemicals.

    2. If you don’t wear the device 24/7, wipe off any moisture before storing it. Don’t store in non-breathable material or in a damp environment, e.g. plastic bag or damp gym bag.

    3. Keep the device’s USB port clean to ensure fluent charging and syncing

    4. Open the USB port cover and rinse the USB port with lukewarm water after each training session. After rinsing, leave the cover open for a while to let the USB port dry. Do not charge the device when the USB port is wet.

    5. Keep the USB port cover closed when you are not charging or syncing the device. Close it also after you have rinsed the USB port and it has dried. When using the USB port, check that there is no moisture, hair, dust or dirt on the sealing surface area. Gently wipe off any dirt. A toothpick can be used to remove hair, dust or other dirt from the connector cavity. Don’t use any sharp tools for cleaning to avoid scratching.

    6. Do not leave the device in extreme cold (below –10 °C/14 °F) and heat (above 50 °C/120 °F) or under direct sunlight.

    • Ian

      Anyone know how big a deal the temperature thing is? I’m thinking of buying this, and I’d use it for a lot of XC skiing, down to temps of -5F or so.

  124. dd

    I really recommend this screen protector for the device . It is a perfect fit, easy to apply and ridiculously cheap

    You can get a pack of six for 4,50$ including shipping

    link to protectionfilms24.com

    or you can find them even cheaper on ebay.

  125. SwissMr

    Love the watch and have been using it for quiet a few months now. The only thing I miss is an altimeter.
    I wish they add it in the next updated version. V800 I find ugly and too expensive.

    What is a decent runnign watch on budget with built in altimeter currently?

  126. Rajeev Arora


    thanks to your extensive reviews, i was able to close my decision and have bought Polar M400.. i am very happy with my decision and the watch is exactly as you have described.

    i needed a few clarifications
    1- i notice that GPS keeps dropping.. is that normal.. i am doing a run around buildings where one side is clearly open

    2- if i sync data with mobile app, and not with PC, the same is still available in polar flow site.. so, then there is no need to separately sync with PC, right?


    • 1) I wouldn’t say it’s normal, but it’s also not uncommon with GPS watches in certain scenarios. Hard to know how big the buildings are (i.e. NYC, or just a few floors).

      2) Yup, correct.

  127. Ciaran

    My Fr305 has given up the ghost and whilst I would like to go to a FR920XT or a fenix 3, my funds wont stretch to that. I have the garmin swim watch and an edge 500 computer. So really I am looking for a running watch.
    I was thinking of getting either FR15 or Garmin vivoactive watches, which can use my existing ant+ heart rate strap. Is FR15 a bit basic? Is the vivo active a bit buggy? I then looked at the polar M400 and whilst I am a garmin person in the main like the look of it but would have to spend another £ 40-50 on the H7 to get heart rate.
    What do you think?

  128. Spiderham

    I have had the watch for 1week love it for tracking my exercises however I seem to have a problem with the activity tracker. It has me lying and resting when at times I have been pretty active or sitting at my desk. .. Is it faulty or am I lazy or have I not set it properly… Thanks for any help…

  129. Duane

    Hello, love the reviews. I apologize if this has been asked and answered but I can’t read 1900 + comments and replies (kudos to you Ray for keeping up on such things). My question – my Garmin FR305 appears to have died – won’t hold a charge, at least it won’t turn on even though battery says fully charged. Can I use my HR Strap that came with the 305 with the Polar M400? Many thanks.

  130. Pete Parfitt

    A quick couple of questions if I may.

    I have just ordered an M400 and had some questions. The Polar beat app doesn’t estimate caloric burn for activities such as walking and cycling (I.e. GPS tracked) without the heart rate monitor being worn. Is this case for the M400 as well, I.e. It will only track caloric burn for activities which have an attendant HRM track.

    Other apps such as cyclemeter and walkmeter will estimate caloric burn, an issue more with cycling than walking, but having to wear an HRM for all cycling would be a pain.

    Related to this, what is the best way of tracking calories whilst walking, to start a workout (without an HRM) or to let the 24/7 tracking take care of this.

    Apologies for the basic questions, and I could wait for delivery, but I’m keen to get started when it arrives.

    Also excellent review, as ever, and loving the podcasts as well. This review really influenced my buying decision, long may Ray reign!

  131. TadasMax

    Just got M400 after this review. Really pleased with it so far. Anyway, is it possible (and how) to import activities from Runkeeper to Polar Flow?

  132. Paulo Sousa

    I’m having also problems with synchronizing my M400.
    Today I have a greater issue. Made a good race and it only synchronized the distance, time and calories. No map, no laps (most important), no pulse and I have the data in my watch!
    Tried to synchronize severall times with iphone app and cable. Can anybody help me, please?

    • Mark Hughes

      If you have the full details in the app but they’re not appearing in the website, try “editing” the run in the app by (for example) setting the “how did it feel” or adding a content. On android, at least, this forces the app to reupload it to flow, resolving issues like this.

    • Paulo Sousa

      Thanks, Mark Hughes but the problem is that full data is only on the watch. I tried synchronizing with the app and cable and the only data that passed is distance, running time and calories. No laps, no heart rate.

  133. Tom G

    Is Polar Personal Trainer something different to Polar Flow? Can you use it with M400?

    • frankis

      Yes, polar personal trainer is different than flow. PPT was a web only app for some of Polar’s older watches. It is not compatible with the newer watches like the m400.

  134. Matthew

    hi ray, thank you for the extremely comprehensive review and thoughts on the M400. i am considering this watch and was just about to pull the trigger and then garmin announced the new FR225. you can find the M400 for $185 w/ hrm and wanted to know if you had any thoughts on “which” watch? i know you consider the M400 a fantastic value but the FR225 looks very compelling. thanks for your thoughts!

    • The FR225 is definitely probably a better all around watch, considering it includes the optical HR sensor (which for me, so far so good). But it’s also at least $125 more than the M400. So it really comes down to how much you value the optical HR sensor aspect.

    • Matthew

      Thanks, Ray. Cost aside I am leaning towards the Garmin.

  135. frankis

    Anyone else having problems with the Training Views losing the auto lap pace display entry after syncing with a mobile flow app? If I add the auto lap pace to a training view in the web app and then sync it with the watch, it’s fine for the first sync. But when I do a workout and then try and sync again, even though I haven’t changed the training views, the auto lap pace entry gets deleted. In fact, I think the auto lap time also gets removed as well.

    • runnershigh

      Hi frankis, I have the same issue regarding auto lap fields in every sports-profile after sync (I just sync via usb-cable). The profiles which contains added “auto lap fields” gets changed if I sync a new training session to flow. I allready wrote it to the polar customer care. They work on fixing the problem, but they also say it could need a lot of time until the problem is fixed.

    • frankis

      Ok thanks for the info. Good to see it’s at least being worked on. It’s a really strange bug. Not sure why it should take so long to fix. It’s very frustrating to see firmware updates come out but this bug still remains.

  136. Ben Michael

    hi Ray, hi guys. i am about to buy the M400. i have 2 questions (things have been written here about them but i am not sure if these are allegations or solid confirmation).

    1. does the watch count/estimate calories if I decide to run without the provided HRM?

    2. does the watch count/show BPM indoors (gym, IF no gps)

    these are really important for me, i would really appreciate some feedback on that.

    thank you very much.

    • Kale

      Yes, the caloires will still estimate without a HRM, and yes, the watch will show HR indoors. I use mine about 4 times a week for weightlifting in a gym with the HRM.

    • Ben Michael

      Thank you, Kale. I just got mine last evening and I did a test run with it. It is so small and light. I was expecting a bulky, heavy piece 🙂

      I noticed that the calories shown when no HR in present are sooo off, i mean it showed 120Kcal burned for 0,5 KM slow walking….

    • SK

      I already reported that issue to them. When walking and not using a HRM, calories seem to be way overstated, while they are way understated without it. When running, I always use the HRM, it seems more accurate then.

  137. Pedro Agrafos

    Hello, I use TICKR X Workout with my smartphone when I´m training and compete. Last moth I damage my phone on water with a waterproof case.
    So, I really interest tochange to Polar M400 (nice features and low price). Do you know if this watch works with TICKR X Workout? It can sync all the metrics? Most importante for me HR and cadence (spm).
    Thank you very much

  138. Gary Lu

    We have one week left in June and still there has been no update for us Android users: 1) No smart notifications 2) the android flow app is slow and buggy. Do you think we will see something from Polar before the end of the month?

  139. Christian Köhler

    How long does the battery last with footpad for distance /pace and gps off? Is that an option for ultra running?

  140. anis

    thanks for the amazing in depth review, i am new to running and trying to figure out between m400 and vivoactive. initially vivoactive seemed good option but lack of training and workout feature is a concern. you mentioned “In November, Polar will also add to Flow the ability to create pace/speed targets.” would you know whether this actually happened?

  141. Heath

    Very disappoint with this watch just after 2 months of usage. Started out great but now GPS signal keeps dropping for no apparent reason on my usual route which have no problem when i stated using it. polar flowsync is a pain in an ass to use, my computer no longer recognize the watch and refuse to get new updates even when it could still charge and this means that I am unable to even sync my data with bluetooth.

    • Heath

      GPS acquisition time was horrible for me probably due to the fact that I am living in city area. However my expectation was higher since I am comparing it to the Garmin F620 which have no problem in my area. If this is the only GPS watch in the maket, I would have agree with Ray on the GPS module for a product of this size but, when there are better module in the market, the m400 fails miserably. Still, have to thanks Ray for the In-depth review. It is polar that screws themselves up after that, especially with the training target which no longer preview correctly in polarflow after one of the update and they still do not bother to correct it and this really shows how much they care about what they are doing at all.

    • Hmm, have you tried calling support?

    • Heath, you unit is broken/malfunctioning. Have it replaced.

    • Christian Koehler

      Hm, works very well in Berlin. Broken watch?

    • Heath

      Yes, but lets just say that after-sales support isn’t that fantastic in my country. Really like the design of current polar watches but probably be looking at brands now till polar clears everything up.

  142. Ben Michael

    Hi Ray, Hi Guys. Please help me with a thought. I just got the M400 last evening. I just want to make sure I am not having a defective unit, maybe this is how it was designed.

    The up,down,start button can be pressed really easy and they acknowledge the press with no effort BUT the Back button has to be pressed a little bit deeper/harder in order to have the press recorded. I thought it was made to be this way so you don’t pause/stop an activity by mistake with the arm.

    for m400 owners, do you have similar behavior with your back button, or it can be pressed as easy and light as the other buttons?

    thanks a gazillion times!

    • Ben Michael

      I just wrote to Polar Customer Support and they replied that all buttons should have identical feelings of pressure when pressed, they said it might be a defective unit, they recommend exchanging it for a new one.

  143. Dom

    I bought 3 watches for my family and within 2 months, and after being very pleased with its functionality and ease of use, I have changed my opinion. The watch itself is still great, but the sync/charge part is terrible.

    About 3 weeks after buying the M400, I started having syncing problems via USB. I didn’t think much of it, since I could still sync via bluetooth and just charge via USB.

    2 weeks ago, my watch completely stopped charging via USB. I sent the watch back (which took about a week) and so far haven’t heard back yet, other than they received the watch. My wife’s watch is at the stage where she can’t sync via USB and charging is frustrating because it keeps connecting/disconnecting. My guess is she’s got about a week or maybe 2 left, before she won’t be able to charge either. We’ll have to send it back as well at that point.
    Please note we have been following the guidelines posted on the Polar website with making sure the port is completely dry and clean etc.

    At this point I would not recommend this watch to anyone considering how frustrating it is having to deal with those sync/charging issues, which is quite regrettable, because other than I do like the watch.

    I am looking at the Garming 920XT, which is bit more expensive, but I don’t mind paying more if the quality is good. For a moment I considered the V800, but I’m not going to buy another polar product if the current issues are not resolved to a satisfying degree.

    Hope this helps people decide if this watch is for them.


    • Just out of curiosity – have you been using the Polar provided micro-USB cable? As there’s been some discussion that folks have had some troubles with 3rd party cables (for reasons that defy logic).

    • Dom

      yeah, I’ve tried out 4 different cables. I even ordered the ones someone posted here. It made no difference.

    • Dom

      I also just heard back from Polar. They shipped the watch back this afternoon, so I expect it back probably on saturday or monday.

    • Scott

      Same here – issues started with sync issues when using the polar cable after 2 months of usage. Using the cable of my Sigma Rox 10.0 I could sync for another 3 months or so but finally last week not even charging worked anymore (with any of the cables) hence sent it to Polar with no feedback so far. One of my bike mates maded exactly the same experience.

  144. Martin

    Maybe someone can answer this..I can add a workout to my favourites afterwards,and they show up in the favourites tab.However,if i want to add a training for a certain day and use 1 of those,the list is empty when clicking “favourites”.

  145. runnershigh

    I have done a big mistake on my flow web diary. I deleted my last uploaded training session.
    The training session is allready on the watch (m400).
    What can I do to upload the training again and not loosing the training session on the clock after next sync as well? Hope, somebody can help me! Thanks.

    • KilkennY

      Og you ser lucky The V800 downloader might also work with the m400.
      But it’s just a guess.

    • KilkennY

      Sorry. I meant:
      If you’re lucky…

    • runnershigh

      I was not lucky. The V800 downloader is really nice! After starting the tool it shows me two training sessions. Both of them are on an later date as that training/competition I am missing now. On the m400 the stats about this training may be allready shown but the whole data itselfs is gone since this last fatal upload on flow.

      It was my fault anyway but I wish on the flow platform (cloud) would be a “restore”-button, so user can restore the state for the last 10 changes for example.

      Of topic; I personally don’t like the new “washed” flow design. The colors before seems more strong & clean to me. The actual design is a step back in my mind.

  146. Sean Stanley

    I just picked up the M400 and love it. For anyone having trouble syncing with the USB cable, if you are using a laptop, make sure it has a full charge and/or is plugged in. I was trying to sync my watch yesterday but none of my many micro USB cables would work. I thought my batch was defective. I finally plugged the laptop in because I noticed the battery was getting low, and I know some devices when low on battery will start shutting down certain features to save power (or depending on your power save settings – not sure which it is). As soon as I plugged in the power the the watch was recognized and it synced right up.

  147. Kicki

    My wrists are between 13-14cm…will the white polar M400 fit? I am struggling between M400 and Garmin fr 220.

  148. Gary Lu

    Well the end of the month is here, and no update for M400 for us Android users. Arre there no Android developers in Finland?

    • MikeJ

      I just updated my watch today, something to do with stability so I might be a few weeks out of sync with others. But then my M400 hasn’t been giving me any real problems or issues, and I don’t really need phone notifications right now. Oh well, all is well, or at least well enough for my needs.

  149. ClarkB

    So I’m loving my M400 so far. I’ve had it since March and all has been well.

    But the last few runs my heart rate has been going pretty wonky, and today the last half of the run was all over the place. Meanwhile the track of the first three quarters of the run was not at all accurate. Any suggestions?

    • GeForce

      Similar issue happen to me today. After updating my M400 to version 1.5, my heart rate reading went up to 102% while i was waiting for my GPS signal to lock on. During the run, my heart rate went from 90% to 42% while i was running. Went to check my H7 sensor battery level using Polar Beat and it indicate that my battery level is full.

  150. Brian

    Hay Ray,

    Good morning. I’ve been using my M400 for running and cycling since it was released and so far it’s a great device. Thanks for all your reviews!

    I know Polar is pretty busy getting their software and updates in line but I was wondering if you’ve heard any news about them including optional software updates/upgrades for a price? You mentioned in your review Training Load and Training Recovery as a possibility for the M400. Those are 2 metrics I would like to see.

    I may just purchase the new M450 to get me that information in Polar Flow since that model has those metrics. My understanding is I will see that information for the M400 as well? Although I not sure the M450 has enough features over the M400 to justify the expense. Any thoughts on that quandry?

    Let me know what you may have heard.


    • It doesn’t sound like buy-ups are on the short (or even medium) term radar right now.

    • Brian

      If I do purchase the M450 do you know if that will that give me those metrics in Polar Flow for the M400 as well?
      Not unlike you having a V800 in your Polar Flow account and you had Traing Load in your M400 review.

      Thanks and Happy 4th!

    • Benjamin

      You may find this of interest. A couple months ago, I noticed that if you tried the “relive” function, where it creates a small movie of you workout, the training load was actually displayed in the info box at the beginning and end of the clip. I got in touch on Facebook with Polar to ask them what that was and if it was going to be added to the calendar view. They just replied to say it was part of something they were working on and to stay tuned. It has since disappeared.


  151. Alex

    I’m a new M400 user, and I’m having a tough time finding some answer to a few usability questions (maybe due to the relatively small user base?).
    * Is there a way to edit runs/routes after the fact? If I check my route on Polar Flow, there are inevitably signal drop-offs that show up as cut-off corners, etc. I don’t expect perfection, but I’ve used other services (Runkeeper, for instance) that all easy editing of routes after they’ve been uploaded. Am I missing something on Polar Flow, or is there no way to “Snap to Road” or otherwise adjust the recorded route to the route you actually traveled?
    Thanks for the great site!

    • Benjamin

      I’ve been using mine for 6 months, and as far as I know, you cannot modify the route itself. Though you can modify the distance in flow when you select a specific workout and click “more”.


  152. Andrew

    I am trying to decide between the M400 and Garmin Forerunner 220.

    I have the HRM strap for Garmin that came wit my Edge 500 so I thought that was a plus for Garmin.

    However I am still tempted to get the M400 and possibly buy HRM strap later.

    Is it still worth getting the M400 over Garmin 220 even though I might be without the HRM for a while? Is the M400 that much better?

    • runnershigh

      Batterie-Lifetime & size/weight is for FR220.
      M400 have a bit more functions.
      If you use the watch without HR-measuring I would suppose the FR220.
      If you permanently use the watch including HR-measuring, then I would take the M400.

    • Of the two, I think the m400 looks best: better shape, nicer materials, metal buttons, very sharp and contrasty display. I also like the way it works (the user interface), really easy to get used to and to operate. For me these were important issues.

      But the GPS is not very good, especially in the city. Your current pace is inaccurate and slow if you do tempo changes. If you find this important you may want to add a footpod (I did). The beeps are not very loud (even on the loudest settings) and easy to miss. The 220 vibrates. The m400 uses a micro USB cable instead of a clip-on thing. That would be a plus if the connection was reliable, which it is not.

      Polar Flow feels a bit unfinished compared to Garmin Connect. (Polar itself still labels it as “beta”) and misses some important features. For instance, you cannot rename your trainings. They all end up in your diary as 00:45:09, 00:42:45, 00:48:01, impossible to distinguish from each other. Whereas in Garmin Connect you can call them: 4×8 mins. easy / 6x 1 min. strides, Running with Bob, etc.

      Also I did not found a way to upload directly to Strava from the Polar.

      So, despite the M400 being a nice watch with lots of features and a very good price it is definitely not “much better” than the FR220.
      If you already have a Garmin heartstrap the FR220 is a good alternative.

    • Tim

      Go with the Garmin — the M400 has problems with the USB port failing. Also, there have been lots of stability issues when syncing to the polar flow website. Overall, the M400 has lots of nice features, but is unreliable when compared to more established products.

  153. Marathon Man

    You can use RunGap to post your runs from Polar Flow to Strava. That will allow you to edit the title to something more meaningful for you before you post to other sites e.g. Strava, Runkeeper, Garmin Connect, Fitbit etc.

  154. Eric Lambert

    I’ve seen other reviews kill this watch on its GPS accuracy. Thoughts?

    • Benjamin

      My personal experience is that GPS is fairly good. Satellite acquisition was a bit slow, but an upgrade to the GPS firmware has brought that down dramatically from minuteS, to minute, or thereabouts. Equally going in and out of coverage (e.g. tunnels) has the expected effect, though the GPS catches on much more quickly since said upgrade.

      Bear in mind my experiences have been in the Northern Netherlands, where GPS doesn’t need to deal with any sort of topography. The few times I have had issues was running in small towns where it struggles to remain in line of sight of the satellites, and on those days it was really, really frustrating at dropping signal and generally being a PITA (even after leaving the city behind for open fields), and once it seemed flummoxed by heave cloud coverage.
      Also note that my experience only compares it to smartphone usage (which is what I used previously), and it seems fairly similar to that, expect of course, its on my wrist.


    • I just don’t see that much in the way of accuracy issues. A few people got lemons early on – but I just don’t see many issues widespread with it (any more than any other GPS device).

      If you look at the accuracy results that FellRNR did and dig into them a bit more, you’ll see they aren’t representative of what 98% of the people out there actually run. He’s only measuring on a very short segment (many times over) that’s off-road trail running conditions.

      As for city conditions, I’ve seen both good and bad tracks through downtown NYC – just like any other device on the market.

    • frankis

      I’m someone who feels the GPS on the M400 is poor. The M400 suffers from the same wandering GPS problem that you encountered in your m450 bike computer review. They both utilize a similar GPS chipset. Most people don’t seem to complain because they don’t have any frame of reference. I’ve been using the m400 for 4 months now and have used the garmin 405 and the polar rc3 before and the GPS on those two devices is much more consistent than on the m400. I think anyone who uses the m400 continuously for more than a couple of months who has used a garmin product prior for some time would probably have similar feelings that the m400 gps is not as good as it is on garmin. I think fellrnr’s review is right on the money and I do most of my running in the suburbs, on roads, away from tall buildings.

  155. Carlos

    Hi DC,
    Could you please give your advice between Polar M400 (€169) and Garmin 610 (€199) the two with HR.
    For a road use, 4 or 5 times a week running 8-10kms each.
    Thanks and best regards,

  156. Pieter

    Been involved with (Garmin) GPS’s since the 90’s. VERY happy with the M400’s (GPS) performance. Have done MANY runs (up to ultra distance) since January with it and the accuracy is within spec. (Was a Garmin (Connect) user but switched to Polar and is not looking back for one second. (The Garmin Connect Platform isn’t the greatest either)) DCR tested a Garmin that is plagued with a poor implementation of the GPS recording algorithm, reflecting as ‘corners cut’ etc. If you want to see some observations re Garmin products point your browser over here : link to forums.garmin.com. It seems the Fenix 3 is not that accurate either: link to forums.garmin.com

    I will choose the M400 again over any comparable Garmin.

    • I feel sorry for Garmin right now, their forum is being spammed to bits and it appears the new FR 225 has serious issues with Bluetooth sync; once you loose the BT connection to your phone you have to switch the FR225 off completely and then back on again to re-establish the connection, it will not re-connect.

  157. Swiss

    I have had the M400 for few months. Have few issues I want to check with you guys….

    1) If I sync my data using my PC and then if I enter my Android polar app shoiuld my new data not be already there updated? Similarly if I sync my data via my android app and thewn log in to my polar account via the website should the data not already be there?
    Basically I am having to sync my data once via PC and once via Android app to have all latest data online and on my mobile app.

    2) I am consistently getting 4-5 hours of battery life ONLY with GPS on. On average I do 6 hour training or hikes and this is getting to be a major pain in the backside when the watch cuts off at 4-5 hour point. Can the accuracy of GPS not be reduced littl ebit to get more battery life?

    3) On runs where GPS connection was previously rock solid I sometimes keep gettign constant loss of connection error message.

    Is it worth contacting Polar to maybe get a replacment unit?

    • Errol Watson

      In reply to 1…

      I have the same problem with information not showing up between platforms. I found when updating information through my phone (android), I would have to wait for my phone to sync with the service before I could see it on the computer. Sometimes it could take a few minutes. The same thing would happen from computer to phone but not as often.

  158. Andrew

    Thanks to everyone who helped me decide to get my M400. Had it a couple of days and on the whole I am very happy with it. It feels solid and we’ll made.

    However I have a problem with the sleep detection. I kept the M400 on my left wrist overnight and it recorded 22 hours 49 minutes of sleep 0% restful. It also recorded a lying down of 7.5 hours which seems about right.

    Anyone else had problems with sleep recordings.

  159. alan

    I think they made a big mistake in not including old fashioned 5ghz compatibility so that this could be used while swimming.

    • Marathon Man

      I think this is intended to be a running watch. The V800 is their triathlon watch that includes swimming & cycling. The V800 is a great product.

  160. Tim

    I tried to sync via the polar flow app on the iphone again today. As has happened regularly since I got my M400, the gps data looks fine on the iphone but when I go to the flow website, none of the gps data is available. This has been an ongoing bug that has not been fixed in several months. Quite annoying.

    The solution is to plug the watch in via USB and sync via my mac. This would be fine is it were not for the corrosion issues that mean that the USB port on the watch fails frequently. I started seeing instability again today for the third time — the watch spends as much time getting hte usb port repaired as it spends on me.

    Unstable software + faulty USB port = do not buy.

  161. Randy

    I have had an m400 since late January and take very good care of it, dont shower with it, or take it swimming. In June the USB port stopped working and it wouldn’t sync or charge. Contact support and it was under warranty but i had to pay $14 shipping to get it fixed.
    Received the watch in late June and now the USB port is having problems again and its only middle of July.
    I don’t want to pay any more money to get it fixed if this is going to keep occuring.
    Has anyone else had this problem? Should I cut my loses and jump to Garmin. I am not happy with Polar! Any other words of advice?

    • Neil

      Sadly, as you will see if you search this and the polar forum, it does seem to be a common issue. Mine is very temperamental with the USB connection (I have about 5 different cables I swap around to get it to connect) but so far it is still charging and I can always sync via BT, therefore I have not yet needed to warranty it, YET. Undertaking future firmware upgrades may present a problem though.
      It would be nice if Ray could update the ‘Summary’ part of his review to make note of this issue rather than it be just in user comments. I don’t expect Polar will announce there to anything being wrong……
      I bought my wife a Vivoactive (it’s fine) and I’ll be getting a next gen Garmin running watch when the M400’s USB does finally fail.

    • konradsa

      Has anybody tried to gently clear the USB connector with vinegar? I read somewhere on the Internet it’s supposed to help.

    • Neil

      I haven’t as I don’t actually think mine is corroded. I don’t wear it 24/7 (just for my runs & the occasional CX bike ride) and don’t go swimming/showering with it etc. I think there may be some tolerance issue such that there is too much free play in the connection?
      Other than that, it is a really good running watch as Ray noted. Just a pity that it appears it will have a limited lifespan due to the connector design.

    • Randy

      Well, contacted support today since they haven’t gotten back to me email and they are going to send me a new watch.
      Now the question is, do I sell it and buy a different brand or hope that it won’t develop issues?
      Hope they don’t send me a refurbished watch.

    • Randy

      Well, it looks like Amazon is actually going to give me a refund since this watch has been having problems. They say there is something wrong with their stock that they don’t even sell them and I wonder if I got one from that stock.
      Anyways, I need a gps watch for training for a marathon this September. I did my first sprint tri this year and would like to do more so I’m leaning towards a Fenix 3. Thoughts? Seems it is Ray’s current go to.

    • Pieter

      Perhaps start reading here first before investing in Garmin?

      link to forums.garmin.com

      link to forums.garmin.com

  162. That’s what I think. Corrosion will not help but mine is certainly not corroded. My watch had (some) problems with connecting from the first week I had the watch. I now use the micro USB cable from my Wacom bamboo tablet that is plugged in my computer already. It fits better and does not give me the connection errors that other cables may do.
    My idea is that all micro USB cables are not created equal and that some provide a better fit then others.

    • konradsa

      Irrespective of whether it’s used on the M400 or not, Micro USB is just crap. Pretty every device I ever owned with a Micro USB port developed problems after a while if it was heavily used. Apple’s lightning connectors (heck, even their old ones) are much better, even after 3 years of daily use with my iPhone and iPads not a single connectivity issue. I am glad all of this USB crap will soon be replaced by USB Type C connectors, which look like something much sturdier and in the same spirit as Apple’s lightning.

  163. Happy No More

    Hi, Just want to add my experience. I bought this watch (using your Amazon link).
    I was very happy with it. Loved everything about it. But within 2 weeks, one of the button got stuck. Contacted Amazon to get it replaced. They were not selling black one because it was under review due to customer’s complaints. (They were still selling white one though.)

    My guess is that there is serious quality control issues with this watch. Amazon still offered to replace with white one, but I was not willing to take chance on it. (Also don’t want a white watch.)

    Now I am trying to decide between Garmin FR15, or Vivoactive. One is old enough and based on even older watch, so it should be pretty solid. Other one just came out and it looks flimsy, but it can do more than just running.

    I am just getting back into running, so don’t really need higher end watches. I just hate ordering something and then sending it back if it is not right.

    • I wouldn’t overthink it. Crap happens, and can happen to any company. For example, while today you posted the Polar M400’s button fell off, someone on the Garmin Fenix3 review posted that the Fenix3 button fell off. Meanwhile, this weekend, on my Ambit3 one of the buttons stopped working till I beat the crap out of it.

      That represents the three leading brands. Every once in a while a lemon slips through – doesn’t matter the vendor.

      I’d say there are a slightly higher percentage of issues here with the M400 and the USB port (interestingly, one of the items I noted way back when on whether or not the new waterproofing method they were using would pan out – since nobody else had used it prior).

      That said, it’s really hard to know percentages. Are we talking 1%? 2%? 5%? For consumer electronics by any company, a few percentage points is completely normal. Unfortunately, most people really only post here these days if they have a problem (or are answering someone else’s problem). It’s slowly becoming a bit of a challenge because it starts to skew things more negatively than reality, since only people who have problems post.

    • Not that unhappy

      I agree with you. It was probably a fluke. I wanted to replace it. But when Amazon was not offering Black unit anymore, I decided to look for something else.

      Well actually I already bought Vivoactive. It was extra $140. Although it looks flimsy, but Amazon is still selling it and I can wear it with suits and stuff.

    • Goeshi

      After reading the comments about the corroding port I made sure i took extra care of mine – rinsing and drying it after each session. However, sadly, today it’s getting sent away for the very reason I tried to avoid.

      I only wear the watch for sports, not day-to-day, and I’ve only had it for 2 months. I have to say I’m disappointed. I know it’s hard to assess the percentage of devices affected based on anecdotal evidence, but i would say that the USB is probably faulty across the board. I doubt it’s a few defective units, more likely an overlooked design flaw that takes months to become apparent. It’s just matter of time and environment.

      Still happy with the device though. This is the only major flaw.

    • Pieter

      Bought my M400 Jan 2015. Supplied USB cable caused a very bad / erratic connection. (Very loose) After sending the watch in I got a USB cable back with it that is so tight it is actually quite difficult to insert it.

      However – also happy, won’t change it for a Garmin etc 🙂

    • LB2004

      I wear it day to day (and obviuosly during training); even used on the beach (little swimming and some canoe, but definately some contact with sea water) and use no particular care (rinsing it with me under the shower…). I just NEVER charge it or connect it to pc unless it is perfectly dry. I have had issues with some specific cables but those working seem to do so consistently. I just bought (actually by mistake…) on Amazon a 5 pack of Aukey cables (model CB-D5) that actually work, so the cable problem seem to be solved. Just to be safe, I’ll probably stop wearing it on the beach and use my old Loop (they interact very nicely, but I’m starting to really appreciate notifications on M400).

  164. MikeJ

    Status report as of 22-July-2015:
    I wear my M400 as a daily watch, use it on walks and runs and have also used it on a few short bicycle rides. GPS acquisition is acceptable, functionality is just fine, no real issues with charging it, no problems with one charger cord or another. Occasionally I will get a failed bluetooth sync between the watch and my android phone, but the information is still there. All in all, no problems to make note of. I even took it on a vacation recently to the Seattle area and the Olympic Peninsula and used the watch to record short walk segments so I could look at them later on the Polar Flow map to see exactly where I was, no problems.

    Hopefully my experience with this watch will continue to go well.

    MikeJ, currently in Wisconsin

  165. Does anybody know if the M400 can display information from the Polar Stride Sensor in realtime on the watch face display screen?
    Eg. Im running and it shows me 160 steps per minute ?
    And/or can set a range of say 150-170 steps, and if running outside of that range it will beep and alert you in real time?


  166. 1. Yes, it does display your cadence on the watch. It won’t show 160 instead of 80 though.
    2. Not that I know. You can do this for pace and heart rate, but not for cadence AFAIK.

    I do not use the officially supported Polar Stride Sensor but the Adidas speed_cell instead, it could be that the Polar version offers more functionality, not sure. Other users may know.

  167. Stevie Headley

    Hi all, great site and loving the podcast. Bought a white M400 with H7 HRM in Newcastle (distant city in the far north of England) back in December 2015. Has worked faultlessly as a running watch (including my first London Marathon), on a skiing holiday in Austria, and for the last few months as a daily watch including my 26 mile round trip cycling commute. Have had no significant problems at all. USB port remains fine, syncing does seem to take quite long i.e. 3-4 minutes, but it has been a great buy, was using phones and the like before to track myself, but a watch is better. Wear it in the shower, wear it at night, no special care, etc. If you fancy a break from Garmin would definitely recommend. Think polarflow is actually pretty good, can of course get better, but there is enough there to bore most people.
    Not waiting for the M450 or V650 though, going to try polar beat and a sony xperia zr. Reckon I can glue a Garmin compatible mount on to the back of it and have a highly capable waterproof bike computer for about £120 pounds. Have had great success with Nokia 500 used in this manner and sportstracker but it is getting a little long in the tooth now, and my sweat seems to be messing up the touch screen.

  168. Kevin

    I have the M400 and an Android phone. I just ordered the Polar stride sensor for the M400. How do you calibrate the stride sensor using he M400 since the Polar Beats app for android does not support the stride sensor?

    • Riaan

      Inside the sport Profile, where the stride sensor is tied to (walking/running, etc), there is then a setting to either manually, or automatically calibrate it. Automatic is done whilst running, with a GPS, at a speed of at least 7km/h. It is all explained in the manual also..

  169. Maciej


    Regarding battery life. I dont know if enyone else noticed it but when i have like 100% of battery and go run for an hour it would take around 10%-20% of battery which is fine for me. But when i go cycling after this running sesion for around 2-3 hours battery indicator is showing way more usage than it sould be (according to 1:30h = 20% usage). What i ment is that after those two trainings 1H run + 2-3H cycling battery indicator is pointing around 20%-30%. Is the cycling mode more complicated than running mode and it would take more battery than on running sesion? Did anyone else noticed it? Thanks 🙂

    Also, many thanks DC Rainmaker for such great reviews! 🙂 i always check your page when buying equpoment 🙂 IMO you’ve got the best page to read about watches after buying them!

  170. frans

    I received a new M400. (Old M400 did not charge anymore)

    I noticed big improvements:
    – GPS fix in 2-3 seconds (was 30 sec with old watch)
    – Sync works fine. (Had to resync several times with old watch)
    – Correct heart rate. (Incorrect values during 1-2 minute of run using old watch).

    Want to buy footpod. I assume that M400 works fine with Polar Stride sensor Bluetooth Smart only?
    (Not with Polar S3 or S3+)

  171. Pieter

    FWIW : I suspect a firmware update improved the satellite acquiring process. In the past I had to stand still (outdoors) with watch facing up for a while to make sure the GPS have a 3D fix, and nowadays I get a good fix already in quite a short period while still indoors preparing for the run 🙂 (Without keeping it still etc etc)

    • frans

      If quick GPS fix is related to firmware, it should be improved in 1.6.4 and/or 1.5.15. I had 1.5.14 running on my old watch.

    • Magnus Helander

      It’s crazy fast now – less than 5sec when starting a run and approx 10 sec when in a car/bike or similar moving. Good job Polar, very impressive.

    • konradsa

      The GPS fix has gotten much better now. They did fix something in their latest firmware release. Even though the A-GPS feature was released in version 1.5 of the firmware, it didn’t seem to work right, the GPS fix did take as long as before for me. But with version 1.6 now, it has greatly improved.

    • Kale

      I agree as well….I also used to have to stand still and couldn’t even lower my wrist from looking at my watch or it would tell me to ‘stand still’………

      Now while I’m driving to a group ride in my car I start searching for satellites and it acquires then while i’m in my car still.

      Very good improvement there!

  172. Kale

    I just bought some bluetooth headphones and had a weightlifting session today. I started working out and the HRM worked for about 10 minutes and then the HRM stopped working completely……Am I out of luck trying to use bluetooth headphones and the Polar HRM at the same time? Really frustrating that this won’t work at the same time. Is there some trick I can do?

    Thanks in advance for any advice/help.

    • There’s no conflict between those two froma technical later – so it’s likely something else (could just be a bad battery on the HR strap).

    • konradsa

      I have the same problem, it only happens to me when I work out in the gym on the treadmill, outdoor runs are fine. After 10-15 mins the watch always loses the heart rate on the treadmill. I know the HRM keeps working, since the treadmill keeps displaying the heart rate via GymLink. It only seems to happen with a specific brand of Bluetooth headphones I am using indoors, when I use different headphones outdoors I don’t see this issue. I already tried reset, new battery, etc… to no avail. It all started with the 1.6 firmware update that enabled support for smart notifications, before that never had this issue.

      I encourage you to report this issue to Polar, for instance via their Facebook page. I already did, and they told me that they are working on a fix, but I didn’t get the impression that they were able to put their finger on the exact cause yet, and I am sure the more people complain the more urgent it becomes for them.

    • Kale

      That’s what I was hoping you would say (and thought was true) but wanted to double check. I just put a new battery in it last week, I wonder if I need to clean the connections or something. I’ve been using the strap for 4-5 days a week since February…..do you think it could be starting to ‘go bad’?

      I’ve gone through about 3-4 batteries in it since February as well, so I have them on hand to use.

      I’ll try it again today and see how it works. Here’s a screen shot from yesterday. I even tried turning my headphones off for a few minutes to see if it would re-connect and it didn’t. I hope the strap isn’t going bad.