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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 April 9th, 2021 @ 10:16 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)
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
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
Tidal Tables (Tide Information)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+ Lighting ControlNoNo
ANT+ Bike Radar IntegrationNoNo
ANT+ Trainer Control (FE-C)nONo
ANT+ Remote ControlNono (but can control GoPro)NoNo
ANT+ eBike CompatibilityNoNoNoNo
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
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. Si

    Further to my earlier question – regardless of price which watch is better for running; M400 or V800? I see that the V800 has some additional features (recovery time etc) that the M400 doesn’t have, and visa versa (PB’s) with the M400 having a better review for finding GPS (time wise).

    If both watches were the same amount of money – which is best for running? I know the V800 has a hefty price tag but I’d rather spend it for the better watch and also get the additional sport features (swimming, cycling etc) in case I decide to do a triathlon in the future.

    For now, though, I want to focus on the running aspects – which watch is best for running only, regardless of price?

    • konradsa

      Ignoring price, v800 is better. V800 got a better GPS and a lot more features. Whatever few features the m400 has more, the v800 will probably get via firmware updates. But for a pure runner, I think m400 has much better bang for the buck.

    • Si

      At the moment it is just running but that may change in the future. If the v800 is the better running watch (not compared to the cost) i think i may get that instead. It’s got some nifty features that i like aswell.

      Thank you – i think you’ve helped me make my mind. V800 it is 🙂

  2. Alex

    The speed and pace zones feature that comes with 1.3 sounds awesome!

    However, I just did the update but can’t figure out where to set the aerobic and anaerobic speed tresholds.
    Was expecting to find it next to the HR limits in “settings” but is not the case (yet?).
    When I try to create a training using a phase based on speed zone, I get a “no speed zone data” message.

    Has anyone succesfully used the new feature yet, and care to explain where to set up the speed zones?

  3. @Alex link to flow.polar.com > Edit Running Profile > SPEED/PACE SETTINGS

    • Alex

      Thanks a bunch!

    • MikeJ

      Also looks like you can set Speed/Pace zones for Treadmill Running as well, I didn’t check if it is there for Trail Running. I did not see it for the Walking activity.

      (tapping my fingers waiting for the android app update next….)

    • ASR1927

      I don’t know how this is supposed to work for treadmill with speed/pace zones as there is no support for foot pod? From where will the watch get the speed/pace?

    • MikeJ

      No idea why or how, just that I saw the feature in the Treadmill Running activity. It could be that footpod support is closer than we think. Has anyone with a footpod tried to sync their M400 with the pod after updating their watch to this latest release?

    • konradsa

      Yes,I tried. The footpod still doesn’t show up at all as a Bluetooth device on the watch when you attempt to sync.

    • It won’t. There’s no footpod support in the M400 at this time. How and when treadmills will be supported is still being discussed a bit.

    • konradsa

      Do you have any more insight on why footpod is still not supported Ray? I am growing a little frustrated by that. Considering that the SOCs of the v800 and the m400 are probably very similar (except for GPS chip and ancillary sensors, such as barometer), it should be very easy for them to port the footpod support from the v800 to m400. Indoor running season is upon us right now, and the footpod support would definitely be nice.

    • At this point they’re saying they’re not going to support the footpod, but instead introduce pace and cadence internally via the accelerometer (like many other watches).

      I’m arguing that WDR based pace/cadence is inaccurate and that nobody to date has done to accurately (on the market), and I certainly don’t expect them to be any different. I think it’s great if you want to have that too, but that the focus should be on providing footpod support. Because I believe that the people that care about having pace/distance indoors tend to be the same people that care about having it be accurate.

      And yes, I’ve noted pretty strongly that by time they get cadence released at the end of Q1, and pace released at the end of Q2…nobody cares anymore. Whereas I noted simply pulling in the V800 footpod code would be quick and easy.

    • konradsa

      Thanks Ray, please keep telling them that! I will definitely shoot them an email too to support what you were saying. I have already purchased the footpod based on the information I had received in this review, as well as directly, from Polar that it will be supported for the M400 in the near future. I am using it with the Polar Beat app right now, but I was definitely planning on using it with the watch. If they drop the planned support now after they had told differently before, I will be extremely disappointed.

    • Stephen Thomas

      How frustrating! Sometimes Polar is so pig-headed about doing things “their way” despite the fact that it would be easier, and better for their users, to follow industry convention. In case it does any good, I’ll add a post to the Polar forum, although there isn’t a topic for M400 (last I checked) so I guess I’ll add it to the V800 forum since that’s where the M400 comments seem to live.

      Please, Polar, just add the standard footpod support ASAP. If you want to do wrist-based cadence, that’s super cool too, but give us something we can actually use.

    • konradsa

      Already received a response from Polar support, see below. Anybody that really wants footpod support, please make sure to send them a message, post on their Facebook page, etc. to make your voice heard.

      Dear xxx,

      Thank you for contacting Polar Customer Care!

      We are looking to develop cadence internally via the accelerometer along with the Stride Sensor support. It has not been determined that we will no longer provide this feature.

      To follow further developments, please follow us on Facebook or Twitter . You can also subscribe to a newsletter to get the latest right to your inbox. Stay tuned for further news.

      Thank you for training with Polar!

      Polar Customer Care

    • Laramie

      I just sent a message to Polar customer support. I’m not on facebook or I’d alert them there too. Actually might create a temp account just to shoot a message there about the lack of footpod support. The more people speak up, the more likely changes are to happen soon.

    • MikeJ

      Maybe I’m reading into this too much, or maybe wishfull thinking/interpretation on my part, but having spent many years dealing with communication and interpretation and mis-assumption issues in an engineering department, I’m seeing the possibility of the following:
      = = = begin quote= = =
      We are looking to develop cadence internally via the accelerometer along with the Stride Sensor support. It has not been determined that we will no longer provide this feature.
      = = =end quote= = =
      1. “We are looking to develop cadence internally via the accelerometer…”
      2. “…along with the Stride Sensor support.”
      3.” It has not been determined that we will no longer provide this feature.”

      So, to me, I read that they are looking at footpod (aka speed sensor per my definition of speed sensor) along with using the internal accelerometer. I read that they have not decided yet as to which feature, either or both, that they will be going forward with. So, to me, I don’t see the footpod as being excluded yet, but then I don’t have the contacts internally withing Polar to know for certain.

      To me, if footpod support never comes to the M400 then I’ll save $50-$75 by not having to buy one and can instead put that money towards a Rhythm+ sensor.

      I’m open to correction, but maybe I’ve also spent too many hours in technical writing and English creative writing classes which keeps my footpod hope intact.

  4. @Sandy The white watch strap seems, at least not obviously, not to be shorter than then black one – if you like I can compare/measure it today evening, when my GF comes back. The adjustment holes have a bigger distance, which is quite weird for a woman’s watch. The watch strap is quite long. The white watch comes with a black chest belt – but a white chest belt is separately available.

    • sandy

      Yes, I would like to see if it’s shorter. Also, please ask her if she thinks it is showing dirt since it’s white.
      Also, does anyone know if the strap can be replaced with something else? It looks permanent.

    • @Sandy Well, we have the watch only since some days. So it’s and looks still new/fresh/clean. The band is interchangeable by user, but I don’t think you can use other bands then the original. About band length… I’l measure it today evening, from now in about 6-7 hours, and post the result for you.

    • @Sandy I’m sorry for the delay, but the train had issues with snow/cold, so it became too late yesterday. This morning I could measure/compare the bands…

      The white one (band hole side is about 1cm (=0.04 inch) shorter – the band buckle side has same length.

      The white one looks (after about a week) still like new. No tracks of “make up” or so. Just shiny white. 😉

      Hopes that helps.

  5. Jason L

    Just did the update to 1.3 (watch shows 1.3.2), and there’s something I can’t figure out. When I go into the diary, and a previous day’s run, there’s no longer a page that shows my average pace. So after finishing a run, I can’t actually tell how I did. It was on the watch before the update (I know, because I used it all the time). Did a setting get reset or something? Or was this removed?

    • Jason L

      Actually, it’s also missing lap data and heart rate zones. I’m thinking this must be happening for runs that occurred prior to the update. I can’t imagine all of that would have been removed intentionally.

    • Patrick M

      For the old data, the average speed (not pace) is still there, lap data and heart rate zones are gone.
      New data has everything, including the new data about speed/pace zones.

    • Laramie

      You mean data on the watch, right? Is the old data still on flow?

  6. Great review. Thanks a lot!

    Just two questions –
    is there a profile for cross country skiing and hiking as well? Or can I create those on my own?

    I’d like to use it primarily for biking, cross country skiiing and hiking -> then import to Runkeeper.
    Would you recommend it?

    Or is the SUUNTO AMBIT2 S the better choice?

  7. @Andreas These link to youtube.com are the available Sports. You can use every selectable sport only once – and you can’t rename them.

    • Thanks Boris. Looks good.

      As I read this watch is primarily made for running, but you think it’s ok for my use as well?
      I just want to track my activities (duration, time, altitude) and upload them after my activity.
      Did so with my smartphone until now, but it keeps crashing and/or messing up the tracks.

  8. @Andreas “As I read this watch is primarily made for running, but you think it’s ok for my use as well?” If it doesn’t bother you that you can’t edit the name of the activity… why not. Maybe worth to consider… the display is only some sort of plastic; don’t know if it’s robust enough for “cross country skiiing and hiking”… as always it depends on your needs. Form my urban needs – which are maybe different yours – the M400 is fine. For “hard outdoor activities” I would possibly choose another one.

    • Should be fine then.

      I’m not a hardcore “sports guy” – the contrary.

      I’m usually quite safe on skis and hiking trails, so that should be a problem. I won’t use it for week long hiking trips in the mountains.

      For € 160 I just might give it a try.

  9. @Andreas Keep in mind that the GPS tracking costs lot of battery; the M400 has no GPS power save mode for long activities. I don’t know if it will come as (paid) update.

  10. j rem

    Can anyone tell me how to use recovery advisor functionality with the M400? The review said via “training load” but I am not even seeing that on the Flow display.

    • Wil

      Anything on the foot pod or stride sensor???

    • @j rem: No… “(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.)” […] “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.”

    • j rem

      I did see that quote in the review, but he has it listed in his product comparison chart that is specific to the M400 that recovery advisor functionality is via training load.

      Not sure why it would be listed on the M400 specific chart if it is not available. Sort of sloppy if it isn’t. It is one of the reasons I purchased this one

    • @j rem

      “Sort of sloppy if it isn’t.”
      Don’t agree… any sort of mistakes (espcially with this sort fuzzy/large amount of data/functions) can happen everywhere. Ray Maker did a great job on this review.


    • Laramie

      If Polar lists a feature as available that, in actuality, does not exist, that’s sloppy. Otherwise, it’s up to the consumer to gather/compare product info.

    • Sorry, I didn’t see that was still in the tables. Just tweaked it. I had however a while back changed it to be pretty clear in the review itself.

      The reason I believed it was in there was that it did show-up online since I already had the V800 tied to my account. Of course, no way for me to know otherwise. And unfortunately despite multiple groups of Polar folks doulbe-checking it after publishing, nobody caught it either.

  11. Steve

    Hi, trying to do update on my M400. On the sync screen is says could take up to 10 mins. After about 10 secs it takes me to my Polar home page. In my watch it says firmware 1.2.4 not 1.3? My daily activity on watch shows 3% but app on mobile shows 8% and I have lost yesterdays daily activity on my watch, would this be related as no previous issues before update. I have updated Flow app to 2.2.1. Any assistance on the above much appreciated, thanks.

    • MikeJ

      As of 8:31am U.S. Central Standard Time (you can adjust to your local timezones) I just tried going to the Flow.polar.com website and it was under maintenance , then I checked my android app and there is an update available for Polar Flow, so maybe try to update your watch again and see if that resolves any issues.

    • spounz

      Updates & application are under maintenance.
      Suggest you wait for tomorrow.

    • MikeJ

      uninstalled the android app ver 1, installed the latest Polar Flow app, logged in, sync’d phone with M400, took a few minutes for the watch to complete sync’ing, and all looks good to go.

      Now to get some sort of activities done to see how this watch and app play together, but with the outside temps here currently hovering somewhere around zero deg F I think I’ll be doing indoor stuff.

      But, yippee, it’s alive. Now to just wait for the pod support (which will give me time to buy/order one).

    • bianca

      Trying to sync my M400 with the andriod app but its not working…any advice? The update came out this early am.

    • MikeJ

      Quick test completed:
      1. short 5 minute “other indoor” activity with HR strap, no gps, indoors (at work, took a lap and a few flights of stairs). Saved on watch.
      2. turned on phone bluetooth, opened app, sync’d watch to phone app.
      3. logged onto flow.polar.com with the desktop computer and the 5 minute activity was already there.
      Results: success.
      Me: happy.

      Now to just get my rear in gear and start actively using this system. Hopefully by the time the warmer weather returns I’ll be ready for it.

      Thank you Ray for providing this site, it is appreciated.
      Mike J (in frozen Wisconsin, formerly from the not as frozen Seattle area)

    • ASR1927

      Yes i did try to sync with the Android app and it works. Great! Now let’s hope for that foot pod support.

      So you’re a cheesehead now? Sorry but that don’t impress me 😉

    • Steve

      Yes, all good now, thanks

  12. bianca

    Trying to sync my M400 with the andriod app but its not working…any advice? The update came out this early am.

    • MikeJ

      ensure that your phone’s bluetooth is turned on,
      then open the app and it should say to hold the M400 “back” button to connect,
      then you might have to enter the device code from the face of the M400 to get it to connect to the phone the first time,
      once connected my seems to sync automatically.

      I did have to uninstall and reinstall the app on my phone to get the update to work.

      If none of that works for you then someone else will have to help.

  13. wilderaz

    I’ve been receiving “Syncing failed” errors since updating the M400 firmware and the iOS Polar Flow app. The devices connect fine. The M400 then connects to the app and the sync process begins and continues apparently normally. However, when the process completes, the M400 displays “Syncing failed.” It appears that all data has transferred but I cannot confirm this. Has anyone else experienced this issue or have a solution?

    • KilkennY

      I had similar experience long time ago. I had to delete the flow app en reinstall it. Only problem is that the flow only syncs data one month back, so all older data will only be available on the flow web service.

    • Ryon

      I was having the same problem while trying to connect right next to my desktop and router (possibly interfering with the connection?). I would get to the screen which required that I enter a pin to confirm the sync and it would fail. I tried later in a different location and it worked fine. The sync takes a couple minutes so you’ll know when it works.

    • wilderaz

      The problem is not location based. Bluetooth pairs fine. The devices connect, the M400 connects to the app, sync begins and proceeds for a period, and then the M400 displays a message that, “Syncing failed.” It appears that all the data has transferred from the watch to the app but I cannot confirm this.

    • 1LightningFan

      I’m having the same problem with the M400 sync failing. Looks like the data transferred though, but it seems to take a considerable amount of time. I’ve uninstalled/reinstalled the app, downloaded most recent updates, reset the M400 to factory defaults, turned Bluetooth on/off, but I still get the sync fail message. I’ve used this watch for less than one week – way too many issues for such a short period of time. Anyone have any advice? Does it go back to the store?

    • 1LightningFan

      I’m having the same problem with the M400 sync failing. I’ve uninstalled/reinstalled the app, downloaded most recent updates, reset the M400 to factory defaults, turned Bluetooth on/off, but I still get the sync fail message. I’ve used this watch for less than one week – way too many issues for such a short period of time. Anyone have any advice? Does it go back to the store?

    • 1LightningFan

      I’m having the same problem with the M400 sync failing. I’ve uninstalled and reinstalled the app, downloaded the most recent updates, reset the M400 to factory defaults, turned Bluetooth on and off, but I still get the sync fail message. I’ve used this watch for less than one week – way too many issues for such a short period of time. Anyone have any advice? Does it go back to the store?

    • 1LighningFan

      Sorry for multiple posts – the blog said my post wasn’t accepted.

  14. CH

    Everything works perfect for me on Android. Love this watch.

    My battery is always on 100%….I wish it was more accurate and showed the drain.

  15. Emmanouil

    I’m having the same problem with the M400 sync failing.

    • Spounz

      I had the same trouble
      You got to supress the sync between your iPhone & your watch, then connect again and the sync will work

    • wilderaz

      What do you mean by, “suppress the sync between your iPhone & your watch”?

    • bosmelet@gmail.com

      When you first used the watch, you paired it to the iphone with the bluetooth.
      First, suppress the pairing
      Then, do it again.
      That’s all, folks.

    • wilderaz

      Tried it. No success. Still receiving the “Syncing failed” notice.

    • Bosmelet

      It worked for me yesterday and no mort sync today


      sync with iPhone 6 iOS 8.2 & m400’s lady formatée update does not work !

    • bosmelet

      …sorry for typing…
      I meant since M400’s last update
      Ios 8.1.2 & firmware 1.3.2 don’t work together

    • Patrick M

      same issue here. Since 1.3 firmware syncing is very difficult. It only works if I synchronize without the app being open (put the iPhone/iPad on the Settings > Bluetooth page, then press lower left button on watch to start sync).

    • wilderaz

      I’m still getting the “Syncing failed” error no matter what I try. I have contacted Polar support but have not heard back. Hopefully others are also contacting Polar regarding this problem.

    • I think it may be more of a Flow thing, than an M400 thing. Flow was up/down a lot for me yesterday, though seems somewhat stable over the last few minutes…

    • wilderaz

      It’s been going on unabated for approximately one week, possibly since the 1.3 update. The sync error occurs between the M400 and Polar Flow app on my mobile device, in my case, an iPhone 6. As far as I can tell though, all information transfers. FYI, also originally from DC and have enjoyed many of the same S/B/Rs and races as you. Keep up the great work!

    • Spounz

      I have the same issue with polar flow on iPhone.
      Sync fails, and now I canot connect to polar system
      What a mess since the last upgrade !

  16. Stephen Thomas

    Factory Reset from the Flow Sync app cleared it up for me.

  17. firsthuman

    PolarFlow can export activity files as .tcx. However, it fails in some points 🙁

    Until now i found the following issues:
    1. WRONG time zone
    2. Pauses are NOT encoded
    3. Calories are NOT included the exports anymore (it says always “0” = zero). This is actually a new problem since they they introduced Laps into the exports.

    Anyone found additional issues?

    Any chance that they will fix this soon?

  18. Megan

    Hi everyone,

    I, like many others, was very excited about this Android support for Flow. With a few attempts I finally managed to update the app and sync my M400. I am now wondering, where is all of my running data on the app? I only seem to be able to view my daily activity. I thought the app would be a mini version of the Flow site. Does this sound right or am I missing something?

    • Agree, not very intuitive swipe left edge of flow app to the right – voila! A menu! With Activity, Training Diary, Info, Settings…

      I think the APP developers have adopted this hidden menu on left edge as “Industry standard” but for mortals who do not spend their day developing mobile apps this is not yet “standard” or expected.

  19. Grant

    Any idea if Polar plans to increase the volume of the training sounds vial a firmware update? The auotolap sound which even on the “very loud” setting is barely audible outdoors and is easily drowned out by moderate suburban traffic noise. (Not everyone is fortunate enough to be able to train in the tranquil Nordic countryside). The volume of the autolap notification on my now retired Garmin FR405 is significantly louder and the lap summary stays on the screen for longer. Apart from these two gripes, I’m happy with my Christmas upgrade.

    • John

      Yes, I want this too. Volume way too low.

    • Travis

      This is one of my biggest gripes so far coming from a Garmin 405CX. The beep is so low on this watch. I ran a night run through my neighborhood and any amount of traffic drowned it out.

      I have had the watch since Christmas and love it so far. White band is staying clean too. Now I just want footpod support and a louder beep.

  20. Mark

    Any update on when the polar m400 foot pod will be released?

    • See my post comment here for a bit more detail: link to dcrainmaker.com

    • konradsa

      Please contact Polar support and tell them how important footpod support is. They are considering dropping it.

    • Mark

      @Ray thank you. @konradsa will send a message now.

    • Doug

      Looks like they listened 🙂

      link to updates.polar.com

      Stride sensor Bluetooth Smart support for Polar M400

      We know you’ve been eager to hear information about M400 and the stride sensor support. The wait is over, and boy do we have some good news to share with you! Polar will bring the Stride sensor Bluetooth Smart support for Polar M400 by the end of Q1. But there’s more – at the same time we’re developing an intelligent way to measure distance, speed and cadence utilizing the accelerometer for both M400 and V800. We’ll let you know the schedule for this later during the spring, so stay tuned!

  21. Niel Venter

    Hi Ray, Any idea if the M400 battery life can be extended by adjusting the GPS sensitivity? I need at least 11hrs battery life and all i see is 8hrs with nothing on the adjustability as with other watches.. Thanks

  22. @Niel Venter No… this option is (unfortunately) not available for the M400: link to evernote.com

  23. I’m a bit torn–I like the M400 for being more “svelte” than all the modern Garmin’s but frankly for some reason it’s not the most comfortable thing for me. Especially all day as an activity tracker.

    Also–GPS accuracy sucked on my normal run in Seattle. Never had an issue but it was always loosing signal.

    The big thing for me is I’m not primarily a runner–I want to this year run more but that’s besides the point. I’m a Climbing Cyclist 🙂

    Normal Weekly Routine:
    – Rock Climbing 2-4 times
    – Conditioning Workout 1-2 Times (1 hour)
    – Run 1-2 times (Winter and sub 8 mile runs)
    – Bike 1-2 times (Summer and 30+ mile rides)

    Would I be better served by a Garmin 920XT? Perhaps a 620?

    I just want everything to be in one platform, one training calendar, one plan, and all tracked…

    Any thoughts Ray? Anyone? It’s the non-running/biking that I really want to get data, HR, and calories (I know they’d be fuzzy).

  24. Steve

    Hi, love my M400. When I haven’t been wearing the watch on daily activity display in the app mobile and desktop it showed greyed out lines(all good, understand) but now it shows white like I have been sleeping but haven’t been! No big deal just interested as to why? Thanks in advance for any feedback or help. Cheers.

  25. Steve

    Hi, love my M400. Up until very recently on my Polar app mobile and desktop in my daily activity when I wasn’t wearing the watch it displayed greyed out lines, no probs I get it. Now it is just white when I am not wearing it like I have been sleeping and records I have been sleeping when I haven’t. No big deal just interested why. Thanks in advance for any help or feedback.

  26. Richard

    Polar just announced the A300 watch. Its the little brother to the the M400, same watch without GPS.

  27. Tried the fitness test today on my M400 and it didn’t work because of a non-Polar HR strap. My plan was to use the M400 with a Wahoo TICKR X for many reasons.

    Too bad, that this core feature of the M400 doesn’t work with non-Polar straps. In my opinion this is an violation of the “Bluetooth smart” sign, that polar uses on the box and on their website.

    Will this probably be changed through a coming firnware update?

  28. Hello folks. Is there problems importing M400 .TCX files in Training Peaks, apart those signaled here by firsthuman #1130 ??

    • Mike

      It’s a general problem with TCX files I think, basically because they can get so large and the exported files from Flow seem particularly verbose.

      Apparently switching Training Peaks to classic mode can help. Have a look at this thread on SlowTwitch for more details link to forum.slowtwitch.com

  29. Marcin

    Hi all M 400 users 🙂
    Just a short question – syncing with mobile Adnroid app is working fine but… on the flow web site i see just a daily activity – trainings are not imported (in mobile app there are visible but not transfered to web flow).
    Have yuo encountered similar issue? Do i need to plug it in to USB to import training sessions?

    Thanks for the answer 🙂


    • @Marcin

      Till today morning not any real syncing issues for GF&me (two watches). But the Sunday (today) hasn’t been synced to the website – or only does not show up…who knows. Have attached the M400 via cable and synced via FlowSync… now the web is up to date too.

      Well, this is really still beta :-(( what @polar settled up here.

  30. Gentle Gigant

    Hello to all
    I have the same problem like Steve:

    – “Up until very recently on my Polar app mobile and desktop in my daily activity when I wasn’t wearing the watch it displayed greyed out lines, no probs I get it. Now it is just white when I am not wearing it like I have been sleeping and records I have been sleeping when I haven’t.”
    Anyone else?
    Thanks in advance for any help or feedback.

    • Patrick M

      same here with my m400. It clearly falsifies the sleeping metrics.

    • Or more likely, there’s just some sort of time/timezone error going on currently…

    • ASR1927

      I don’t have this issue. It still show in grey/white lines for the periods i don’t wear the watch.

      I don’t have the problem like Marcin either. Trainings uploaded via the Android app is transfered to Polar flow as expected.

    • Gentle Gigant

      Can we do something to correct the issue?
      I did not fully understand how it is some sort of time/timezone error?

      Thanks for your help

    • steve

      Hi, would this have anything to do with the current sync issues? Is there anything I can do or will it just fix itself in due course?

    • Patrick M

      weird, when I charge it for two hours, I get the hashed lines, but when I take it off 20 minutes before sleeping to take a bath, it’s as if I have slept for 20 minutes!

  31. N Brunton

    watch or loop? which did you like better? which would you use more?

  32. amanda

    Sorry if this is a stupid question but does this watch work without the heart rate sensor? Or do you always have to wear the sensor to get activity information?

  33. Luke

    Hi Ray,
    Is it possible for Polar to do a firmware upgrade to enable the M400 to receive analog hr details from a H7 in the same way the new A300 does? I’d really love to collate accurate info from my swims.
    Also, why can’t Polar come up with features such as the replacement bands in different colors for all of their new models? Surely it can’t be that hard?

    • spounz

      Still no reaction from POLAR since the disastrous update to 1.3.2 firmware : sync between M400 and polar flow on iphone fails.

      Should I ask for a replacement ?

    • Luke – My understanding is that the chipset doesn’t support it

      Spounz – Sorry, I can’t remember, have you opened up a support case with them? If not, I’d definitely do that. If so, I’d call back and push them.

    • spounz

      Yes i wrote yesterday to the support team in France.

  34. Team Polar said: “Hi there! We are experiencing data sync issues and we’re working on it with high urgency. We ensure you that your data is safe. If sync is not working, please try again in couple of hours.”

  35. Damien

    Hey DC – 2 things – first, was just in a local GPS store Johnny Appleseed here in Sydney Australia looking at watches and mentioned a really good online review site, and before I could tell the guy, he said “DC Rainmaker?” – anyway, just thought you should know your detailed and thorough reviews are appreciated down here in Australia.

    Ok, secondly – and I realise I could probably form a view by reading all your material – but, I’m replacing my old garmin 405cx – key functionality I want is for running – need bluetooth upload (so I can upload data to strava via iphone 6); heart rate is a plus, though I haven’t used it as much as I should (don’t love the strap) and I want waterproof for a little swimming, but don’t need stroke counter / indoor capability. Tossing up between the Polar M400 – Tom Tom Runner – and I guess Garmin 220? – also open to other options – would very much appreciate your thoughts.

    • Given that, I’d go with the M400. That said, definitely check out the Vivoactive from this morning as well.

    • damien

      thanks, will have a good read through the vivo review – looks a little more multi-tasking than I need – doesn’t seem to have HRM (I’ll check review on that) – still a bit in love with the optical HRM of the Tom Tom Cardio run – the all in one does appeal. Plenty of good choices out there it seems!

  36. William Nunez

    Fantastic review and now the proud owner of the M400. However i want to track cycle activity with HR as well as track the cycle ride on my Bryton Rider40 (which is easier to read on handle bars). result, 2 HR Straps, one Ant+ the other BT LE.

    Is the solution the wahoo trackr or trackr Run? If the m400 will track footpods in a later upgrade, will the wahoo tracr run look like foot pod data or is this data redundant without a phone with wahoo app to inetrpret it?

    In other words should i just get trackr and polar footpods when the functionality appears.

    Any help would be apprciated

  37. William Nunez

    Sorry an additional question. Why is there no training load for the M400 on the flow website. If its HR and VO2 max dependent.

    • Simply for upsell purposes.

    • William Nunez

      Dont answer, this has been answered a few times in the above

    • firsthuman

      There is actually the training load indicated in the beginnings of the “Relive” videos of your runs (for example “reasonable” or “extreme training load”), which suggests that the loads were already computed for this runs and are just not shown in the calendar view … 🙁

  38. Adrian

    Thanks for the review. I have made the purchase here in Melbourne. Perhaps you could set up a code with polar.com.au similar to Clever Training to get the benefit to you.
    Good luck in Paris. I’m glad the box didn’t fall.

  39. Phil

    I’ve had my M400 for about 6 weeks now and have been very happy with it, despite it being returned once already for condensation building up under the screen. However, I’ve measured two rides recently using both my M400 and Strava with the following differing results:
    – 7 Jan 20.4km Strava, only 15.19km with the M400
    – 1 Jan 31.3km Strava, only 25.81km with the M400
    Obviously, these are some massive differences. After reading the above comments I will try resetting the watch and hope this fixes the issue, otherwise it may have to go back again. The ride was very twisty – could this have been the issue? If so, how come Strava can track it?

  40. JRT6

    I can’t get my m400 to pair with my galaxy S3. Both the m400 and the app are stuck in search mode.

    • Frans

      My S3 (Android 4.3) works fine with M400.
      Did you update firmware of M400 to 1.3?

    • JRT6

      I’m having a hard time getting the watch to update. I don’t know if it’s because my lap top is too and is the source of the problem or what. I do have to fiddle with the USB cord to get it inserted just right for the watch to even sync.

    • Jason L

      I had the same problem, but mostly solved it with a good-quality USB cable. In what seemed like a totally unrelated incident, I could not get a low-power computer that I’m toying around with to boot (ECS LIVA). It is powered by a usb cable. Replacing that cable allowed the computer to boot properly.

      I’m finding that most USB cables are of questionable quality. I’ve since spent a few $ on good-quality cables (search for “Anker USB cables” on Amazon, but be sure to use Ray’s link to get there :)).

      That said, I would still have the occassional problem. The computer would make a “usb inserted or removed” type sound on and off, like the connection was failing. It seems to be that if there is any moisture at all in the watch’s USB socket, it will have trouble.

    • JRT6

      Well I plugged the m400 in today and it synced, updated and everything on my first try.

  41. Luka

    Hi guys,

    i just bought M400, updated firmware to the latest version and went for a test run. GPS accuracy is terrible; most of the run GPS location was 20m off, check the link below, i was running on the roads next to a gps track
    link to shrani.si

    Is this normal, anybody else experincing such issues? So far i was tracking my rides using HTC One with Sports tracker or Strava, GPS accuracy was always spot on!

    Cheers, Luka

    • konradsa

      Hi Luka,

      Unfortunately, your experience is normal. The M400 has some accuracy issues. Looks like the watch didn’t have a good fix for the first couple of kms, as your track towards the end is much better.
      Please contact Polar with this experience, they have been promising GPS fixes via firmware.

    • Luka

      Thanks mate,

      i’ll contact them, hope they improve it in the next firmware update. But currently as it is, accuracy is really bad, i haven’t seen a track so much off. I’ll try to reset the watch and do a couple of more runs. If this doesn’t help, i guess it’s the best to return the watch . Too bad, otherwise I liked it.

      Cheers, Luka

    • Patrick M

      I noticed similar situations where the route was off by approx 20-40 m, especially in the beginning. So far, since the 1.3.2 firmware, I haven’t had it so severely. I am disappointed that the firmware apparently didn’t resolve these issues… 🙁

    • The accuracy is not good, yes. But – at least as I can compare it – not worse than with the RCX5, which also had some accuracy issues.

      A run (yesterday) M400: link to flow.polar.com
      A run (month ago) with RCX5: link to polarpersonaltrainer.com

      You need to switch to satellite view and zoom in to see how bad it is.

    • Niek


      Here is a link of a run i did with my M400:
      link to flow.polar.com

      In my opinion the accuracy was acceptable, but I don’t know what GPS-accuracy is “normal” these days? (this is my first sportwatch)

      When you compare the GPS-accuracy to other watches, for example the Garmin FR220 or the TomTom Multisport: How accurate are these watches (or other GPS-watches in a same price range)?

      Grtz Niek

    • Magnus Helander

      Hi Luka,
      if this is your first run and first use after updating to new firmware – try to leave the watch with GPS active for 15-20 minutes under clear skies. The GPS-system provides something called an “almanac” which is downloaded to your m400 – it helps the chip to locate and track the satellites..

      To get best performance and results from your m400 you may want to read the FAQ about the GPS-system on this link link to gps.gov
      Your watch is actually tracking and detecting ridiculously small time shifts between signals from four or more satelites. A few years ago you needed a truck to do this.

      I was also worried about the precision of the m400 and have benchmarked it against an iPhone 4 and against my old Garmin FR210. What I have found is that the m400 has great tracking and GPS-precision, even better than an iPhone with cellular assist if you ask me.

      Here is a map where I have overlayed the iPhone track on top of the m400 track. Parts of this run is in the forest, other parts on dirt roads.

      link to files.helander.fastmail.fm

      Good luck

    • David McElroy

      Your route looks quite accurate, but some parts of mine are terrible. The left turn after point 3 and the straight before point 5 (Total wrong side of the road on a dual carriageway with a large central divider)

      link to flow.polar.com

    • Niek

      David McElroy,

      Your link to flow.polar.com isn’t working, so I can’t see your route..(is your profile set to public?)

    • David McElroy

      Sorry, was on private. Thought that button meant make it private 🙂

    • Luka

      Hi guys,

      just for the record, for all the runs and rides with the exception of the first one, gps accuracy was spot on. I guess it was an “almanac” issue, as Magnus mentioned a few posts earlier.

      Thanks for your help!

    • Niek


      I have my M400 for a few months now and my experience is that sometimes de GPS-accuracy is acceptable/good and sometimes it is not good.

      Do you think download this ‘almanac’ to my watch will increase the GPS-accuracy (despite the fact that i alreay have done a lot of runs)?

      Besides that, Is downloading this ‘almanac’ a procedure that you can do once (after the firmware update as you described) or will it be usefull to do this more often (to ‘refresh’ the almanac) to increase accuracy op the GPS.


  42. Team Polar again:

    “We’re sorry to say that we’re still experiencing some sync issues. We’re working day and night to get the sync working again. If sync via app doesn’t work, please use FlowSync on your computer. We’ll let you know once we’ve solved the issue. Thanks for your patience!”

  43. Stephan

    I receiver this answer VROM Polar today regarding footpod support:
    Thank you for contacting Polar Customer Care!

    We are looking to develop cadence internally via the accelerometer along with the Stride Sensor support. It has not been determined that we will no longer provide this feature.

  44. Stephan

    I receiver this answer from Polar today regarding footpod support:

    We are looking to develop cadence internally via the accelerometer along with the Stride Sensor support. It has not been determined that we will no longer provide this feature.

  45. Stephan

    I received this answer from Polar today regarding footpod support:
    We are looking to develop cadence internally via the accelerometer along with the Stride Sensor support. It has not been determined that we will no longer provide this feature.

  46. Stephan

    I received this answer from polar today regarding footpod support:

    We are looking to develop cadence internally via the accelerometer along with the Stride Sensor support. It has not been determined that we will no longer provide this feature.

    • I talked to them a fair bit more about this at CES this week. While I’m getting some mixed messages, the most recent and highest up message is saying eventually they’ll add footpod support since they originally committed to it previously.

      I would suggest that if footpod is important to you, and if it’s important to you sooner rather than later – then sending that feedback over is important.

    • Neil

      Thanks Ray.
      What’s the best method of providing feedback?
      Was the auto-upload to 3rd parties and the dodgy activity time-stamp situation mentioned at all?
      I don’t mind having to manually upload to Strava but having the time being out compared with others on a run/ride (therefore it’s like we didn’t run/ride together) and also not having any Instagram pics linked is a bit annoying.

  47. DerFux

    I am goeing to get me one this week.
    For the people around Cologne + Aachen / Germany:
    The “Intersport Ducks” Shops have an anniversary offer.
    They give you 15% off on any purchase between January the 7th and the 24th to those who have any “Active Card” (free card).
    That means the watch will be available for 170.- EUR – including HR.
    The watch is available in the shops but I will call them today to make sure that I can get one.

  48. Annie

    Hi, I’ve recently bought a polar m400 and decided to have a read through your review as still getting to grips with all the functions! I know you’ve had a few questions on waterproofing already but I’m a bit confused as usually a watch water resistance mark for 30m (as written on polar m400) doesn’t mean that you can swim with the watch it just means the watch is resistant to rain and splashes. I don’t know if I’m missing something here? After seeing that and nothing about being able to swim with the watch on the packaging or in the little guide, I thought I couldn’t swim with it but after reading your review I’m a bit confused as you say you can. Great news if you definitely are able to do so! But just wanted to double check that the water resistance mark wasn’t misinterpreted!

    • There are many waterproofing urban legends. The 30m isn’t good for anything but rain and splashes is one of them. I’m working on a bit of a debunking test showing how things actually work.

    • firsthuman

      The user manual says:
      “Water resistance: 30 m (suitable for bathing and swimming)”

      According to the manual they divide their products into four categories (cf. the manual) and:

      “Please note that these definitions do not necessarily apply to products of other manufacturers.”

    • Josh Handrich

      I do mud runs like Tough Mudder and Warrior Dash every year. They involve water events where you’re submerged in ice cold water. You’re generally wet and muddy the whole race. Would it be a bad idea to wear the watch and the HRM or can they take the abuse? I’ve only had the watch for two days so I don’t know what its limits are.

    • Nigel Deutrom

      I got this watch to wear in tough mudder and other OCR races as it is waterproof. .wont be wearing the hrm though

    • Nigel Deutrom

      I got this watch to wear in tough mudder and other Obstacle races as it is waterproof. .wont be wearing the hrm though

  49. Annie

    Brilliant! I couldn’t find anything about water resistance in the small start up guide that came in the box but didn’t think of checking online as I didn’t think these things differed. Great news 🙂

  50. joel


    did you talk to polar about a timeline for m400 smart notifications and the capabilities like the v800?

  51. Juan

    Can this watch and the H7 heart rate sensor withstand being in the sauna room (temperature can get to 180 degrees) or will i have to take it off? I sometimes go in for about 1-15min just wanted to know if i had to take it off as well before i go in?

  52. FletchFFletch

    My wife is looking at both the M400 and Fitbit Surge and is concerned about how big the device will look on her small wrists. Obviously there are other differences between the two, but how do they compare in terms of size (I know we’ll see a rolling pin picture in a week or so but she’s trying to decide sooner).

  53. Team Polar says:

    “Hey Flow users! We’ve tackled the sync issues related to Flow app iOS and FlowSync. Flow app Android users may still experience some sync problems. We’re working on it.”

  54. Thomas G

    Hi everybody!
    Do you also have the problem that the height measurement is totaly inaccurate?
    After my training runs I found out that the climbed height of meters is too much.
    Yesterday I started a training session but did not move the watch for 2hrs. The height signal moved between
    75 and 130meter. After stopped, the watch showed a total climbed heigt of 180m!! –> useless function
    I live in a flat area of about 100m height.
    The gps signal was quite accurate within a radius of 50m after that 2hrs.

    Do you have same experience?
    Somebody knows how the height measurement is working?
    …Barometric could explain this big variation…


    • Luka

      Unfortunally, it works like that, altitude data is more or less useless. If you export the workout and import it to SportsTracker or Strava, you get usefull info about the climbed height, which is calculated from .gpx data altitude (usefull only for ground sports).

    • KilkennY

      Hi Thomas.
      There is no barometric altimeter in the M400. It works with typography (gps). So if turn on the gps inside your house, the gps points will jump around because og pour satellite, and the you will get high altitude readings.
      That’s my theory:-)

    • Thomas G

      Hi guys,
      thanks for your help.
      Very interesting link to the gps explanation.
      Seems I have to live with it…
      For challenging tracks I will export the gpx datas.
      Thanks so far.

      Best regards

  55. Stephan

    Updates for polar M400:
    link to updates.polar.com

  56. Phil

    I inquired regarding potential implementation of recovery features in the M400:

    “Dear Mr ****,
    Thanks for your email. Training load and recovery for M400 is in the pipeline but we have no confirmed release date at the moment. It’ll be implemented to Flow web service in 2015.
    Best Regards,
    Technical Customer Support Team
    Polar Electro UK Ltd.

  57. Juan

    Can this watch and the H7 heart rate sensor withstand being in the sauna room (temperature can get to 180 degrees) or will i have to take it off? I sometimes go in for about 10-15min just wanted to know if i had to take it off as well before i go in?

    • Kohhal

      According to the startup guide the recommended operating temperature range is up to 50degC if I remember correctly…

    • Juan

      @Kohhal Thanks for that. I haven’t purchased it yet so I don’t have access to that so I appreciate your help. Looks like I wont be taking it in as 50 degrees Celsius is only 122 degree Fahrenheit and the sauna get into higher temperatures like in the high 180 degrees Fahrenheit (which is between 82-87 degrees Celsius).

  58. @Juan I don’t know if it can… but I personally wouldn’t wear it during a sauna session.

    • Juan

      Ok, thanks Boris, I appreciate it! I haven’t bought the watch yet ( I will this weekend) but after DC Rainmaker posted about them supporting foot-pod and smart phone notifications, it’s almost a no-brainer now especially at that price point. 🙂

      Especially my fears at first about it not being waterproof but after reading this blog and comments, I now know that’s not the case definitely beats the FitBit Charge HR and Surge which are both having issues with the optical HR readings at higher levels.

  59. Juan

    Also, does the M400 have the capabilities to know how far I’ve ran without the foot-pod, maybe by calculating the steps I’ve taken. Will it record the running data accurately?

  60. Jo

    I find with my M400 that my calories i burn is much more then i ever burnt doing the same workout with my old polar FT60? why is that? which one is correct?

  61. Nevzat


    I am evaluating to purhase m400. How I have read contradictary comments about GPS accuracy. The alternative is either garmin fr220 or 620. For pricing point of view, m400 makes sense. I will be using mainly in İstanbul/Turkey.

    With new foodpot support, can it get more pricise?

    What do you recommend for gps accuracy?


  62. Nevzat


    I am evaluating to purhase m400. How I have read contradictary comments about GPS accuracy. The alternative is either garmin fr220 or 620. For pricing point of view, m400 makes sense. I will be using mainly in İstanbul/Turkey.

    With new foodpot support, can it get more pricise?

    What do you recommend for gps accuracy?

  63. Nevzat

    I am evaluating to purhase m400. HoweveeI have read contradictary comments about GPS accuracy. The alternative is either garmin fr220 or 620. For pricing point of view, m400 makes sense. I will be using mainly in İstanbul/Turkey.

    With new foodpot support, can it get more pricise?

    What do you recommend for gps accuracy?

  64. Juan


    I just purchased the M400 based on your review of it and a few others as well as people who have it. My question is. Sometimes if it’s too cold to run outside I’ll run on the treadmill. Is there a way I can get the watch to record distance, time, and all the other factors without gps I since I’ll be on the treadmill and don’t have the foot pod yet (is the foot pod needed or can I do it without it)? Thanks!

  65. I travel a lot and would love for a future smartwatch to automatically change time according to a new time zone. Why doesn’t the M400 do this? Do you know other similar smartwatches that automatically change the time?

    • Laramie

      The M400 updates the time when you sync with your phone (or in my case, ipad).
      Garmin watches normally use GPS to update the time.

  66. UnclePear

    I was doing some track Interval work today with my M400 and it seems like it took anywhere from 100 to 200m before I got a sensible reading for my new pace when starting a new faster interval lap. Has anyone else experienced this?

    • Laramie

      Yep. Much slower than my Garmin 310xt at reacting to pace changes. I’ve already commented on this here. Hoping Polar will release a firmware update that improves this.

  67. Nigel Deutrom

    Couple of things – love the watch and have been using it for both outdoors – running and cycling and a multitude of indorrs acticities ike HIIT and Boxing

    1) Has anyone had the bit of webbing where the straop connects on the HRM Strap start to fray?. I have had the watch about a month and was hoping that it doesnt get worse

    2) As I use this to go to teh gym and have a daily watch I usually take it in the box it came in as I travel on the underground and want some protection whilst in the rucksack. Are there any suitable small carry cases that are available

    • MikeJ

      A woman I work with says she replaces her HRM strap on a regular basis due to the hook wearing through the sewn-in attaching loop. She strongly recommended that I order a spare strap soon even though mine isn’t wearing out (yet).

  68. steve

    Hi, posted before about daily activity displaying white sleep when not wearing during the day instead of greyed out lines as this affects correct readings of sleep lengths. I can see others having same issues. I have emailed support but no response. It is annoying and I would of thought an easy fix as it has been mentioned it might be a time zone issue. Any ideas anyone rather than just being patient? Cheers

  69. Juan


    I just purchased the M400 based on your review of it and a few others as well as people who have it. My question is. Sometimes if it’s too cold to run outside I’ll run on the treadmill. Is there a way I can get the watch to record distance, time, and all the other factors without gps I since I’ll be on the treadmill and don’t have the foot pod yet (is the foot pod needed or can I do it without it)? Thanks!

  70. William Nunez

    yay footpod support and/or accelerometer based stride data by spring

    link to updates.polar.com

    • Josh Handrich

      Great, however basing your cadence off of its internal accelerometers is a bad idea. For one, they aren’t that accurate. Second, some activities like stair climbing I don’t swing my arms. Use an external device, Polar! Garmin already does.

  71. Marcel Delestienne

    M400 GPS accuracy:
    You can display the gpx trace file of the M400 with other software.
    This url (link to visugpx.com) let you do that.
    The trace with this soft is not smooth at all like on Polar flow.The trace looks like stair case with approx 10 meter step.
    The number of points on the M400 trace give approx 2 meter resolution.
    Does Polar use a curve fitting algorithm to smooth the trace?
    For info, using the same soft on a Garmin 110 file indicate a 12 meter resolution.
    Do you know what Polar will do to improve the M400 gps accurracy?
    Are they only improving curve fitting or really improving the raw data measurement accurracy?
    Any feedback is welcom.

  72. Tim

    GPS accuracy is solid. I ran with the M400 and my previous garmin FR305.
    1st test: M400:3,69km — FR305: 3,65km distance
    2nd test: ran 4km together with girlfriend wearing a FR210.

    On both tests they both gave the 1km signal every time within 2 seconds of eachother.

    When M400 says GPS=OK, wait a little bit longer for more accuracy.

  73. Watch faces…
    At the version called “Analog” I’m missing the weekday. The version called “Your name and time” is quite WTF?! Instead a simple version without activity tracker bar would great.

    • KilkennY

      I dont recall ever seeing a analog watch that tells the weekday. Time and date is just perfect for me 🙂

    • @KilkennY It’s very common here (Switzerland). I’m really missing it. Even thinking to switch back to my normal watch because of this.

    • cuh7b5

      I like the “Big” watch face but I miss the date there. There is a small gap above the huge numbers where the battery appears when it is charging. A small date (and probably the weekday’s abbrev.) text could fit there nicely.

      – I don’t like the “Date, time, your name” version either, I know my name, thanks!
      – I don’t use the activity features of the watch, so the “Date, time, activity bar” is again not to my taste.
      – The “Analog” one is ok but somehow I cannot get used to it. I.e. now this is the 6th of july, hence there is a no. “6” at the 3’o’clock position, which can be misleading, I have to think twice to check the time.

      I don’t really miss the weekday, I usually know what day it is. But the date is a must on every watch (and watch face).

  74. Bogdan V

    I bought this watch after I read your review and others comments but now I regret, specially after I installed Android app. Till now I lost 2 of the training activities. It don’t want to sync all data from watch to web. I don’t have the map on the web but I can see it on the phone. I tried to remove the activity from the web and reimport it but it was removed from the watch too.

    I wanted to return the watch to the seller but shipping cost are too high.

    Conclusion: good looking product, good marketing, poor quality of service.
    I will switch on garmin soon.

  75. Josh Handrich

    Has anyone else had problems with connectivity problems with their H7 HRM? I’ve only had my M400 for a week and I’ve had two occasions where it was giving sporadic numbers or the signal was lost completely. I always make sure the electrodes are wet and that they are paired. The only thing that worked was to delete the pair and sync them manually. Very frustrating!

    • William Nunez

      Ive had mine 3 weeks, used 3-4 times a day. Flawless so far. Id try a new HRM battery. If that fails id send it back for a replacement

    • Josh – Outside of making sure that the chest strap is wet (as it needs that moisture to help with conductivity to the body….especially during this time of year with the colder/drier air) it is also important to ensure that the strap sits securely on the body while wearing it. If it is loose, it could result in erratic or no heart rate readings.

      Secondly, try moving the sensor more towards the left side of the body to help with consistency. – Mike @ Polar USA

  76. Mauro Delle Donne

    Hi Ray, I bought m400 a month ago and have subsequently taken it back twice (currently have my third watch) because it will not connect or charge via my usb ??!!! (it does initially but then won’t anymore) I have contacted the call centre but they were not aware of similar problems and could not advise. they did replace the watches though….. Im worried that I am doing something wrong. I have a fairly new samsung all in one pc on windows 8.
    do you know of anything??

    • Niek


      I had the same problem and in my case it was their USB-cable wich wasn’t good (Polar confirmed that this was often the case). Did you test it with another (solid) USB-cable?


    • KilkennY

      Hi Mauro.
      It is important to use the original cable. I did ones experience similar issue, but it was with a non-original cable.

    • Try another cable, and/or try a few different USB ports around your house to see if that helps. Sometimes on computers it will control the power to USB devices which produces some problems.

  77. I bought it but now I regret.

  78. Robert

    I would like to ask you about GPS accuracy. there is some test where Polar M4OO was not so good. do you have any experience with gps accuracy for this sport watch?

    • konradsa

      I got the watch, I think GPS accuracy is good to even great if you run in open country or suburban neighborhoods. But if you want to run in more challenging environments, such as around tall buildings (urban canyons) or inside deep forests, it may be worthwhile to consider V800 instead, it seems to do much better in those environments.

    • Mark Hughes

      I’d broadly agree with Kondrasa here but would emphasise very heavily that the GPS accuracy is exceptionally poor in compromised circumstances, when compared with other GPS devices in the same circumstances.

      Mid-rise buildings and cloudy days seem to cause it much more problems than other devices.

      In good GPS coverage though, it does work well. That’s been my experience with three different M400s now.

    • konradsa

      I agree it’s very poor when compromised, but I haven’t had any issues with weather yet. I have run in dense fog and snow and the track was always spot on.

      Also, something I else I have noticed is that it’s very important to get a good lock before starting the run. The watch showing GPS OK is not enough. I blame this on the autonomous assist feature, which predicts satellite orbits beyond the ephemeris data received from satellites. Since this predicted ephemeris doesn’t seem very accurate, your accuracy will suffer when the watch is using it. It’s best to wait until the watch has the updated ephemeris from all satellites before starting your run. Unfortunately, there is no indication on the watch when this has happened.

    • Mark Hughes

      Interesting – I’d attributed the difference to the weather but it is possible that it’s down to the amount of time between runs, as it may still have some of that data cached from a previous run. Or some other random variation!

      Approximately how long do you tend to wait after getting 100% GPS?

    • konradsa

      Well, depends, sometimes I does take a mile or so when I don’t “pre-lock”. A tell tale sign is when you look at the elevation data in Polar Flow. When the elevation data becomes available, I think this indicates that GPS has got 100% or so fix. I also notice that the route then gets more accurate too. If I let the watch get a lock 15 mins or so before I run, then the track is much more accurate from the get go, and elevation data is also available immediately.

      Also, try resetting the watch using the 4 button method. It looks like sometimes also some old data gets stuck there, and the reset then clears it up.

    • Mark Hughes

      I’ll give that a go, unfortunately most of my runs are at lunch time from work, no GPS reception inside and can’t wait 15 minutes before starting… I can see what you’re saying about the elevation data too – my run today had elevation data from the start and was one the most accurate traces I’ve had with this watch.

    • konradsa

      You can just put it on the window sill for like 15 mins before you run and let it acquire GPS there, that should work too, assuming you don’t work at the bottom floor of a building surrounded by other tall buildings.

    • Robert

      Thanks for your ideas. I want to buy them and I’m slightly scared about accuracy. I don’t run in town so much. More often close my village and in forest..

    • Robert

      Thanks for your ideas. I want to buy them and I’m slightly scared about accuracy. I don’t run in town so much. More often close my village and in forest.

    • Robert

      Thanks for your ideas. I want to buy them and I’m slightly scared about accuracy. I don’t run in town so much. More often close my village and in forest. Robert

    • konradsa

      To give you some idea, here is a running track I did last Friday in heavy snow and fog, it’s pretty much spot on:
      link to flow.polar.com

      But here is a track from a little stroll in midtown NYC. It’s all over the place:
      link to flow.polar.com

    • robert

      Thanks. I’m from middle europe (Prague). I usually run out of town.
      will you anyway recommend M400?

    • S

      Yes, as long as you are aware of the GPS limitations, it’s a great watch. Great features, it works pretty well for me in my environment, and it also looks great, I don’t mind wearing it all day as an activity tracker. A bummer that Polar saved a few bucks by putting in a cheaper GPS chip.

      Keep in mind though that GPS is not very reliable around tall buildings anyways. You can look up many v800 tracks on Polar Flow in NYC that are also messed up beyond usefulness. Luckily, footpod will soon be another option for the watch in these situations.

    • robert

      thanks. as I wrote, I don’t run in town, mostly out of buildings. sometimes in forest. do you think that inside of forest could be also problem for M400?

    • konradsa

      Robert, I don’t run in the woods, so I will let others comment on that. I know there was some Swedish runner on here earlier that shared some tracks in the forest, and he said he was happy with GPS performance. But keep in mind right now, trees don’t have leaves, so that may have an impact too. And there are also some other runners complaining about performance in forests.

      But I am actually able to get a pretty good fix in my house (American two story wood frame construction), so I would be hopeful that it should also be able to get a somewhat decent track in wooded areas.

    • robert

      thanks a lot. still I would like to buy them. will wait on few other comments. 🙂

    • Honestly you’re unlikely to get a truly useful answer. The challenge is that people who are happy with the watch generally don’t post, and people who have challenges generally post a lot.

      That said, for the vast majority of people I hear nothing but happiness from folks on the M400. No doubt, there are a handful of people that see GPS oddities, some of these solved via resets – and others via unit swaps. But, that’s realistically true of every GPS device I’ve reviewed. Some just get a lemon.


    • robert

      If I understand well from you. you would recommend them? There are not the same conditions for testing. every person is somewhere else. it is subjective feeling. there is no doubt that they are not 100% perfect, but if I would like to have it, I would pay much more for perfect ones.
      greetings from Prague

    • Mark Hughes

      Ray – having had my unit swapped and still seeing exactly the same behaviour, and a colleague seeing the same inaccuracies, I think there is a genuine problem with this watch in compromised GPS reception, when compared with other GPS devices.

      That said, it is excellent value and if you’re not running in heavily built up areas I would have thought you’d be very happy with it. Knowing what I know now, having used it for a couple of months, I’d probably still get it again despite the issues I continue to have, as the feature set for the money is still good, and while the inaccuracy is a pain, it’s not enough of a pain to have me go back to carrying a cell phone.

    • spounz

      Seen from Paris, Prague is in eastern Europe.
      (BTW, welcome to EU)

    • robert

      If you like, eastern.

    • Olga

      Ahoj, běhám v lese hodně často a GPSka je většinou velmi přesná. Jenom když je fakt hodně blbý počasí jako zataženo a větrno, není záznam úplně na stezce. Ale ve srovnání s Garminama Forerunner 220, jsou M400 přesnější.

      Just saying I run in the woods quite often and the GPS is precise. Only in really bad weather it’s not as spot on but still much better than with my Garmin Forerunner 220.

  79. jvdw

    Borrowed m400+HRM from my brother; still previous firmware; in my situation: outback, no tall buildings, great watch: instant gps-lock, no crazy tracks, plenty of info, beep on loudest setting ok even with earphones on (music not too loud), will be considering buying my own to guide further training!

  80. GeForce7

    After using the M400 for over 3 months, i find that the GPS signal strength is weak when i’m running on the road around medium sized buildings and trees. I was wondering what could be the possible cause of GPS signal loss while running? Could it be the clouds or due to a faulty device?

    • S

      Unfortunately just the way it is i am afraid. You can try to make sure you get a good lock before going running, and also don’t cover up the watch under your clothing and try to point it upwards to the sky. Beyond that, nothing you can do I think.

    • GeForce7

      What is your take on the upcoming foot pod update for M400? Do you think the foot pod can significantly increase the accuracy of the device when comes to distance, path and speed?

    • Not outside, no. In the vast majority of road running cases using a footpod outside tends to lower accuracy (trails are different), since most people don’t calibrate it each time.

      Adding to that though, is that Polar has always taken an either/or approach in that if you use the footpod with one of their products it overrides the GPS, rather than being just used to smooth pace.

    • konradsa

      But Ray, let’s say you are running in NYC, footpod accuracy should still be better than GPS, no? Even if you made some decent effort to calibrate the footpod and it is still 10% off, the GPS errors should add up to much more than that. See my link here, all the wandering and jumping around of the GPS gives a much longer distance than what was actually run: link to flow.polar.com

    • Of course, in a setting like Manhatten (but not Central Park), then yes a footpod can and should help with today’s GPS units (not just Polar).

    • Uuuuihhh… THAT’S a really bad result. 🙁

    • konradsa

      Boris, I would not read too much into it. When I have some time, I will find you a public v800 track from NYC and post it here. Even the v800 shows similar issues when conditions are less than ideal, but the M400 seems more susceptible to it.

    • GeForce7

      Just to make sure that i understand your point of view, relying on GPS is good enough for road running and foot pod is mainly for indoor running? Thanks for replying Ray!

    • As konradsa said, that’s actually sorta par for the course in downtown NYC with 50-60 story buildings. Sometimes you get a clean run through it, and sometimes it waivers, and sometimes it’s all over the map.

    • GeForce7

      Usually my watch will lose its GPS signal when the sky is partially cloudy in the evening time or it can happen randomly when i’m running beside a road with vehicles, bus stops and small trees (no buildings). The weirdest part is that at one point i was able to run through a path with trees as tall as 8 – 10 meters high and the signal is still strong enough to stay on.

    • konradsa

      Hi, I never had this issue. I have never lost GPS signal anywhere, except for in NYC. I think you unit may be defective. Try the four button reset and see if that helps.

    • @konradusa Don’t worry… I’m quite happy with the M400 and don’t see more or less accuracy than with my old one (RCX5). Posted it here: link to dcrainmaker.com

    • konradsa

      Ok, to compare with my M400 track I posted above, here are some v800 tracks from midtown NYC (you can click on relive button to see they are actually from a v800):

      1) link to flow.polar.com
      Starts off quite bad, then works okay in central park and finishes strong at the end

      2) link to flow.polar.com
      Notice that this one is even still way off on the Queensboro bridge

      3) link to flow.polar.com
      Same thing, way off at the beginning, much better in Central Park

      4) Total train wreck
      link to flow.polar.com

      So even the v800 struggles a lot in NYC.

    • GeForce7

      Before updating my M400 to version 1.3, it took me at least 2 – 3 mins to get a GPS lock. After the update, it took me around 15 – 40 seconds to get a GPS lock standing at the same location with nothing but small trees around me. Do you think my unit is defective?

    • S

      GeForce7, you said earlier you lose GPS signal when the sky is cloudy. That is definitely not normal, and that’s why I think your unit may be defective.

    • GeForce7

      I’m gonna try sending Polar an e-mail regarding the issue and hope that they can assist me.

  81. Juan

    I haven’t had any issues with GPS on the watch but that could be due to me living in a more suburb, rural type area and I’ve had the watch for about a week and the GPS tracks seem to be on target. I will be experimenting more on it and see if any oddities come up. Overall, I love the watch. I still haven’t showered with it just because it’s so new but reading Ray’s comments it seems that it would hold up pretty well in water/swimming situations. I just afraid that the soap/bodywash will slip through the rubber component.

    • Correct on waterproofing. It’ll be up soon to take a dunk in the underwater tesitng chamber…

    • Juan

      I’m not sure what you mean by that. Could you please elaborate? Lol my brain is still fried from work.

    • Juan

      I’m guessing you mean that i’ll need to take a shower or go swimming with it soon and test it out??

    • No, I’ve done plenty of swimming/etc with it. I mean using the waterproofing testing machine I have to test it down to depth: link to dcrainmaker.com

    • Juan

      Ahh, I see, that’s great. So in other words, it’s perfectly safe to take fear out of the equation and just leave it on all day as long and start showering with it and stuff (as I don’t plan on going deeper than 30m underwater)?

      Does chlorinated pool water or salt water have any effects of the waterproofing capabilities of the watch? Will it still work? Just curious as I make this my everyday watch I wouldn’t want to switch it out when on vacation.

      Lastly, lets say you do shower with it daily and occasionally go into the pool or ocean sea and water does get into the port and you dry it out before charging it and one day it stops working, is a replacement covered by the Polar warranty or is that not covered?

      Thanks for your help. You’ve lead to my re-ignition of my fitness lifestyle. I’ve ran more this week because of the watch which seems odd to think a watch could make one be that more motivated. haha. 🙂

    • Joe Adamson

      Technically 3atm or 30m waterproofing is only safe and tested statically (I.e. not moving). Definitely don’t go scuba diving down to 30m with it. Ray seems to think that swimming with it is OK but I would definitely not be swimming underwater at all in them.


    • Ahh yes, the great waterproofing rating confusion. Seriously, it’s fine to swim. The internet folk lore of needing a 100m watch to swim with is highly inaccurate.

      And, actually, you could go down to 30m with it, as that’s the exact method it’s tested. It’s just a chamber that’s giving it the same 30m pressure as scuba.

      Where most watches/devices get into trouble waterproofing is impact, specifically something like jetskiing and falling off which delivers a much higher impact to the seals than 3ATM would.

    • konradsa

      Looking forward to see your article on this topic Ray.

  82. Marcel Delestienne

    Congratulation for this blog that give valuable information.
    What is the four button reset doing and how do you make this reset?
    I am using the M400 since December with very good results.(I am running in the forest( wood) in Belgium.
    The M400 give a gps measurement every second compare to every 4 second for the Garmin ( 110 and 210).
    I confirm like others :
    the low quality of the usb Cable( can be changed easily) ,
    the HRM has given some eratic measurement in a few run ( seems to be link to the connector to the bell),
    the synchronization with the smart phone ( ONE+) fails quite often( known problem from Polar)

    Best regards


    • S

      Regarding the HRM, make sure you wet it before running. I only had erratic measurements once, and that’s when I forgot to make it wet before running.

  83. Magnus Helander

    Many post here are from frustrated user who have problems with their m400.

    I would like to add the perspective of a happy user with zero issues. I sync the m400 to the Flow-site without problems to Windows7 over USB and wirelessly/bluetooth to the Flow App on a Samsung Galaxy S3.

    My view is that the m400 does a great job and calculate current pace in a meaningful manner.

    Distance, pace and duration – that’s what I need on the trail in big readable digits. The m400 delivers that.
    No reboots, no master resets, no lost workouts, no reverse charging – no issues at all.

    Re accuracy I have benchmarked the m400 against Forerunner 210, iPhone4 with Strava App and this weekend the “gold standard” Forerunner 310XT.

    I find the accuracy of the m400 on par with FR210 & iPhone4/Strava.
    The 310XT does a slightly better job however.

    Here is a link to the m400 GPX track on top of the Forerunner 310XT track.
    We run two loops so you can compare them individually as well as against each other.

    link to files.helander.fastmail.fm

    The m400 needs clear skies to get a reading from the GPS satellites so it does not work in NYC,
    nor does any other consumer GPS watch.

    I was frustrated with heart-rate dropouts/weirdness both on my old FR210 and on the m400.
    At the pharmacy I found cheap electrode gel (“bluegel”) for TENS-machines and use if for the HR-belt.
    Result: no more dropouts or irregularities.

    • robert

      Hi Magnus,
      that great to see also possitive reactions. I hope I will have also m400 and add my experience. 🙂

    • konradsa

      Thanks Magnus, I am also generally happy with it. Accuracy is acceptable in my suburban running. I think for trail runners, the v800 is much better, that seems to be the weak spot of the m400 and the sweet spot of the v800, that’s why fellrnr gets such bad results. I don’t think his results are representative of the overall performance of the watch, it’s just that in his particular use case the m400 performs poorly, while the v800 excels. Also, for places like NYC, I think neither m400, v800, or other GPS watches will give very accurate results.

      Also keep in mind that the m400 really needs a good satellite lock. If you only wait till GPS shows OK and then you start running, the watch will struggle for a mile or two.

      One thing about the m400 however that is obvious in your tracks above is that the 310XT is more consistent, where tracks of identical loops are more overlapping than the m400 tracks. How about overall distance though in your testing, does the m400 generally come up with the same overall distance compared to the Garmins and iPhone, or is it consistently long/short?

    • I read Fellrnr’s test of the m400 and his results did not reflect my experience.

      I figured I could compare the two loops of the 14K trail since I run an identical distance.

      The first loop was logged as 13.99, the second 13.95 – with the original firmware, not the latest update

      Strava screenshots here link to files.helander.fastmail.fm

      Again, I think it does an excellent job and you’re right, m400 is somewhat quick on the trigger for “GPS OK” – it does need a minute or two to really lock in the position.

  84. Since Saturday syncing issues en masse; wireless is broken nearly completely, cable works lala. My workouts do not show up or with a delay of several hours. Changed profiles are not synced or only after two-three attempts.


    • Frans

      Using Android flow is noticed similar issues last week. (Workouts appear in polar Flow incomplete).
      Yesterday sync of new workout succeeded after I performed next steps:
      1. Connect M400 to PC using USB cable and sync
      2. Update Android flow to 2.0.2.
      Now all my workouts are correct visible in Polar Flow.

  85. Marcel Delestienne

    Synch failed solved
    The synchronization of my M400 with my smartphone(one +) was failing due to a standby delay of the smartphone set to 30sec ( too short).It is now working fine.

  86. Jeff Gilbert

    I’ve been using my new M400 nearly daily for about 3 weeks. I have found GPS performance to be excellent and highly repeatable in my suburban and rural, open to lightly wooded workout environment. HRM performance has been excellent. However, a few days ago I noticed that during synching/charging, the M400 was chirping and flashing, and then today, the M400 will not synch or charge. I’ve tried two cables and two USB sources, so it appears the M400 micro usb port has gone bad. I have contacted Polar on their web site, so it will be interesting to see how they handle their service.

    • Jeff Gilbert

      Update on Polar customer service. Crickets. No response to online inquiry. No response to email inquiry. On-line chat is dead. Has Polar they gone bankrupt?

    • MikeJ

      their Twitter person was posting earlier today, and their discussion forum is active, so it appears that they are alive and well and are probably working on updates and solutions and developments.

    • In general, I find that most companies web support e-mail response systems aren’t ideal for quick resolution. Neither is Facebook. It’s so much more efficient to just call and get an immediate answer.

    • Jeff Gilbert

      The capabilities of their telephone system are comparable to those of their other customer support systems. The M400 went back to the retailer this afternoon. So endeth my second use of a Polar product.

    • So you tried phone support?

  87. Juan

    Has anyone experienced any red spots or red looking rashes on the hand they wear the M400 on due to the nickel backing or could it just be the sweat trapped on the back? Any suggestions? I really love the watch and would hate to have to switch it.

    • William Nunez

      Not yet, wear it 24/7 for 3 weeks now. Avg weekly exercise 200 miles cycling 20 miles running, so it gets sweaty

    • Nikita

      The backing contains nickel? I was thinking about buying this watch, but if it contains nickel it is for sure a no buy for me 🙁

    • Nikita N

      The backing contains nickel? I was thinking about buying this watch, but if it contains nickel it is for sure a no buy for me.

    • Nikita – The M400 does not contain nickel. Mike @ Polar USA

    • S

      I can confirm that it’s nickel free. I have a nickel allergy, but I have no issues wearing the M400 24/7.

    • Juan

      Awesome! So it could just be an issue with the sweat being trapped after my workouts. It has gotten less reddish over the last few days so it’s not really an issue now.

    • Kale

      Weird…I just go my M400 today and I got a little rash too around the ‘clasp’ part when I put it on right out of the box and had it on for about 30 minutes. I too have a nickel allergy, and surely hope that what Mike @ Polar says is true and that it doesn’t. I had to have the inside of my wedding ring lined with yellow gold because of the nickel that is in silver. I washed the watch once, and hoping it was just some residue of sorts from the manufacturing process.

      I’ll report back once I’ve worn it for a few workouts and report back. Mike @ Polar, thank you adding to the conversation and letting us know that it does NOT contain Nickel.

  88. Andy

    I bought the polar m400 yesterday and tracked my first run last night. An easy 6 miler. I already have the farming 920xt but I’m a bit of a gadget man and the m400 seemed like a hell of a piece of kit for the money. I got it for just over £100. I wore both watches on the run and I have to say there was no loss of Gps from the polar as a lot of people have experienced. I ran in town running but there were no real talk buildings. 3 storey maybe at the most and I live by the coast so it’s fairky open space around. Weather was rubbish, extremely cloudy and wet. The polar lost 0.2 of a mile in comparison to the garmin on accuracy but this wasn’t down to gps loss probably just different satellite connections between the two devices. I found the display a lot harder to quickly glance at than the garmin and found myself navigating towards the 920 for data rather than the polar. Never the less for data collection and an activity tracker the polar is a great device. It probably swings it on looks as an all day watch as well. I’ll be keeping the watch for my backup. I’m an average joe runner nothing special, I run most nights but at a leisurely pace between 9 – 9.30min miles. Average distance about 6 miles with some 9 milers chucked in. I’m a dad of two with two jobs so time doesn’t allow for anything more. In my opinion although only used it for one run I think the m400 serves a purpose for those not wanting to spend a fortune on tech.

  89. Andy

    I bought the polar m400 yesterday and tracked my first run last night. An easy 6 miler. I already have the farming 920xt but I’m a bit of a gadget man and the m400 seemed like a hell of a piece of kit for the money. I got it for just over £100. I wore both watches on the run and I have to say there was no loss of Gps from the polar as a lot of people have experienced. I ran in town running but there were no real talk buildings. 3 storey maybe at the most and I live by the coast so it’s fairky open space around. Weather was rubbish, extremely cloudy and wet. The polar lost 0.2 of a mile in comparison to the garmin on accuracy but this wasn’t down to gps loss probably just different satellite connections between the two devices.

    I found the display a lot harder to quickly glance at than the garmin and found myself navigating towards the 920 for data rather than the polar. Never the less for data collection and an activity tracker the polar is a great device. It probably swings it on looks as an all day watch as well. I’ll be keeping the watch for my backup.

    I’m an average joe runner nothing special, I run most nights but at a leisurely pace between 9 – 9.30min miles. Average distance about 6 miles with some 9 milers chucked in. I’m a dad of two with two jobs so time doesn’t allow for anything more. In my opinion although only used it for one run I think the m400 serves a purpose for those not wanting to spend a fortune on tech.

  90. Andy

    I bought the polar m400 yesterday and tracked my first run last night. An easy 6 miler. I already have the farming 920xt but I’m a bit of a gadget man and the m400 seemed like a hell of a piece of kit for the money. I got it for just over £100. I wore both watches on the run and I have to say there was no loss of Gps from the polar as a lot of people have experienced. I ran in town running but there were no real talk buildings. 3 storey maybe at the most and I live by the coast so it’s fairky open space around. Weather was rubbish, extremely cloudy and wet. The polar lost 0.2 of a mile in comparison to the garmin on accuracy but this wasn’t down to gps loss probably just different satellite connections between the two devices.

    I found the display a lot harder to quickly glance at than the garmin and found myself navigating towards the 920 for data rather than the polar. Never the less for data collection and an activity tracker the polar is a great device. It probably swings it on looks as an all day watch as well. I’ll be keeping the watch for my backup.

    I’m an average joe runner nothing special, I run most nights but at a leisurely pace between 9 – 9.30min miles. Average distance about 6 miles with some 9 milers chucked in.

  91. Andy

    I bought the polar m400 yesterday and tracked my first run last night. An easy 6 miler. I already have the farming 920xt but I’m a bit of a gadget man and the m400 seemed like a hell of a piece of kit for the money. I got it for just over £100. I wore both watches on the run and I have to say there was no loss of Gps from the polar as a lot of people have experienced. I ran in town running but there were no real talk buildings. 3 storey maybe at the most and I live by the coast so it’s fairky open space around. Weather was rubbish, extremely cloudy and wet. The polar lost 0.2 of a mile in comparison to the garmin on accuracy but this wasn’t down to gps loss probably just different satellite connections between the two devices.

    I found the display a lot harder to quickly glance at than the garmin and found myself navigating towards the 920 for data rather than the polar. Never the less for data collection and an activity tracker the polar is a great device. It probably swings it on looks as an all day watch as well. I’ll be keeping the watch for my backup.

  92. Andy l

    I bought the polar m400 yesterday and tracked my first run last night. An easy 6 miler. I already have the farming 920xt but I’m a bit of a gadget man and the m400 seemed like a hell of a piece of kit for the money. I got it for just over £100. I wore both watches on the run and I have to say there was no loss of Gps from the polar as a lot of people have experienced. I ran in town running but there were no real talk buildings. 3 storey maybe at the most and I live by the coast so it’s fairky open space around. Weather was rubbish, extremely cloudy and wet. The polar lost 0.2 of a mile in comparison to the garmin on accuracy but this wasn’t down to gps loss probably just different satellite connections between the two devices.

    I found the display a lot harder to quickly glance at than the garmin and found myself navigating towards the 920 for data rather than the polar. Never the less for data collection and an activity tracker the polar is a great device.

  93. Andy l

    I bought the polar m400 yesterday and tracked my first run last night. An easy 6 miler. I already have the farming 920xt but I’m a bit of a gadget man and the m400 seemed like a hell of a piece of kit for the money. I got it for just over £100. I wore both watches on the run and I have to say there was no loss of Gps from the polar as a lot of people have experienced. I ran in town running but there were no real talk buildings. 3 storey maybe at the most and I live by the coast so it’s fairky open space around. Weather was rubbish, extremely cloudy and wet. The polar lost 0.2 of a mile in comparison to the garmin on accuracy but this wasn’t down to gps loss probably just different satellite connections between the two devices

  94. Andy

    Sorry for multiple posts. Kept telling me post failed

  95. Julian Middlewick

    I’ve had an M400 for a month or so now and overall it seems pretty good, comfy to wear and as a running GPS watch should be all I need.

    However one small but significant niggle……after pressing the start button it seem to take a good 10 seconds, if not slightly more to actually register that I’ve started moving. Looking at the file data from todays run for example for the first 13 seconds of the file speed and distance are registered as zero before picking up that I’ve started moving. To the eye the GPS track looks pretty good but there is a good lag between hitting start and the recording actually reflecting that. It seems to happen every run with the distances off as well, not by much but regularly by the distance I would have covered in those missing 10-15 seconds.

    Not the biggest issue maybe but it does mean that for the 5k races I’ve done over the past couple of weeks the predicted finish time timer is not great. While I appreciate that it is a guide rather than expected to be spot on, and accuracy should improve over longer distances it does make what should be a really good feature of the watch relatively unusable for that distance.

    Anyone else notice this or is it just me?!

    • konradsa

      I don’t really have this issue. When I press start in my driveway, I can see the GPS recording in polar flow start in my driveway. Standard advice for m400: try to wait an extra few minutes when the GPS shows OK. If possible, put the watch on window sill 15 minutes before run, let it acquire GPS lock there, and see if that improves it.

    • Julian Middlewick

      Thanks for the quick reply.

      It had 10 minutes on the window sill outside before while I got ready so had plenty of time to acquire signals and (as far as I can tell) the GPS track is fine. What it tracks it tracks really well.

      Looking back at the running I’ve done with the M400 since I’ve had it the recorded zeros have been from 2 to 15 seconds before the recording actually kicks in so it does vary. Like I say relatively unimportant for training runs but more significant for shorter races and pacing and not something I’ve seen with various Garmin devices I’ve owned.

      My last 5k race it took me 30 seconds to cover the first 10 metres apparently and I’m fairly sure I’m not that slow!!

  96. Jon

    In image 23, which is under the “Size and Weight Comparisons” section, you show the default main screen with just the date and time(without the activity tracker). How did you set your home screen up like that?

    • Andy

      I doubt the paused time would ever be included in the overall activity. That’s the idea of it so you don’t ruin any pace results by having to stop at traffic lights or waiting for something. this then excluded this non moving time from your activity result.

    • KilkennY

      Hi Jon.
      Push and hold the up button for a few seconds to change the watch view.

    • Jon

      I am able to switch between the four watch face options, but in his picture he has the “Daily Activity” face selected but without the activity bar. Is there a way to just display the date and time like in his picture without my name or activity bar?


    • MikeJ

      I remember reading about that either in the review or one of the replies but i don’t recall what the answer was. It might have to be setup via the polar flow website and then sync’d/updated to your phone.

  97. Daniel Gatto

    Is anyone else having a problem where the watch does not count ‘paused’ time e.g. for all my rides the elapsed time equals moving time (even when I have auto pause on, or manually pause the activity)?

    • Daniel – When the watch is paused (whether it be manually or with the auto pause feature) the elapsed exercise time stops. That time if filtered out of the total exercise session for the user. – Mike @ Polar USA

  98. Wesley Forbes

    Hello, I am a new runner but would like to increase my endurance and loose weight. I have been researching fitness trackers and was about to pull the trigger on the FitBit Surge. It wasn’t until I came across this watch and this review that changed my mind on getting the Polar M400. I especially like that down the road there will be even more features added such as notifications, and control of music as I run while listening to music.

    Since a lot of my research was done through this site, I thought it only fair that I help support it by purchasing from Clever Training. What is the usual time in which to hear back from them as there has not been any confirmation from them stating that they processed the order?

    Also, I am now feeling a bit of buyers remorse after reading more comments here of things not working correctly? Ray, do you till hold this unit in high regards as you did when you first reviewed it?

    • If you had placed an order, you should have gotten a shipping confirmation within a few seconds. So it sounds like it might have gotten snagged within the junk e-mail (double check that), or similar SPAM filtering. Since the M400 is in stock, generally speaking if you order by lunch it’ll ship out same weekday.

      You’re best bet is to give them a quick call and they can double-check it, since it sounds like e-mail may be getting snagged somewhere: 844-399-6440 (toll-free)

      Thanks for the support!

    • Wesley Forbes

      Thank you for the response in regards to Clever Training. I did in fact give them a call and they were very helpful and has since sent me an email confirmation and told me that another one will be sent with shipping information once shipped.

      I am still wondering about your opinion of the M400 since you rated it highly when it first came out. Now after reading and responding to many comments about some of the problems with the GPS, synching, and Polar Flow, do you still hold it in high regard?

    • konradsa

      Looks like Ray is dodging this question! 😉

    • Hmm, not really.

      Just a bit busy. Going on a roughly 16-17 hour day thus far, with 8 hours of presenting for my day job, three countries visited by plane, and will be about 11:40PM by time the taxi I’m currently in with my laptop open working gets me home. Plus perhaps 50+ questions answered here on the blog and got a post written too. What’d you do today? 😉

      As for the answer to the second part – no, I haven’t seen anything to indicate otherwise. With any watch you’ll have a handful of people have some random issues. Be it Garmin, Suunto, TomTom, or Polar. Doesn’t really matter. In scale (such as this site), you’ll see people post problems here. But if I look at shipping volumes, we’re realistically talking under 1% of people (assuming there’s a relationship between people that buy via CT/Amazon and people that complain).

      If I look at service availability (i.e. the Flow issues), I can’t speak to Android, I just don’t use it that often. But, for iOS, I’m not seeing issues from folks (and I think only seeing 1 or 2 people with Android issues). In either case, for Flow at large, it did have about a 2-3 day rough period at the beginning of the month. On the flip side, Garmin had about a 10-15 day rough period with spotty service. And Suunto was flat-out offline for a week. Even Fitbit was offline for a good chunk of a day. So by those standards Polar is doing fairly well…


    • konradsa

      Haha, thanks. When do you find time to exercise on top of that? 🙂

    • Not today unfortunately…not today.

    • Neil

      At the time of Rays review it probably was the best bang for buck option and it is a good watch but not if you are in a hurry to get started on your activity or wish to share activities outside the Polar Flow system.
      On that front, Garmin are winning.

      I have contacted Polar about their timestamp issues (therefore exporting issues) which they admit is a known issue but don’t know when or even if they will resolve it.
      The Android situation isn’t good either and we use that and also iOS in my household.

      Now I have the watch, I won’t be returning it but given the above, when I buy my wife a new sports watch, I think I’ll be returning to the Garmin family as I’m confident it will get GPS lock just as quick (if not quicker), it will interact with android phones/tablets and will sync accurately & easily to third party sites. That and the fact that here in Australia the price differential isn’t as marked as in the US….

      Hopefully Polar can get their bugs fixed in a timely manner.

    • Wesley Forbes

      Thank you, I guess the only way to know for sure is to try it myself and see if it meets my needs, which at the moment, is not that much, as i am just starting to exercise more.

      I really look forward to the firmware updates, not so much for the notifications, but for control of my music. Now, I have to either hold my phone while running or pull it out of my pocket to turn up/down or to change songs in my “Running” playlist. It will be very nice just to turn my wrist to take care of all of that and keep the phone in my pocket the whole time!

    • Trevor

      I may have missed something, but do you mind explaining the issues with timestamp and android issues?

    • Neil

      For me, I’ve installed the android app on our tablet and the watch won’t sync and even as a display of activity uploaded via iOS it doesn’t show everything.
      As regards the time stamp issue (detailed by others above); it practically means that if I go for a run with my wife (Garmin) and then we upload to Strava (hers automatically and mine manually), her run appears straight away with the correct start time etc. Mine appears an hour or so later and it looks like we ran separately and started at different times. A by-product of this is that if you normally link Instagram pics to your Strava activities, then those won’t link either as that connection is time related too.

    • Trevor


      Which tablet were you using?

    • Neil

      An Acer.

    • Trevor

      Hmmm.. interesting.

      I wonder if it’s a tablet issue and not a Polar issue.

    • Neil

      The bluetooth connection, maybe but lack of displayed info, doubt it.
      I’ll have another play with it tonight once I can retrieve the tablet from my kids…. :o)

    • Julian Middlewick

      The time stamp issues I’ve been seeing seem to relate to the file being given the time it’s uploaded rather than when the time the run.

      For example I’ve been running to a race at the weekend, racing and running home generating 3 run files all of which have the time that they are synced to Flow and not the start time of the run.

      Because of this sites like Strava and Raceday Apollo which I use think they are the same file and will only upload one of them and reject the other 2.

      I’ve been manually editing the timestamp in TextEdit to work around it. I did email Polar but never got a reply from them.

    • Neil

      Retrieved the tablet and there was an update waiting. Installed it and now I can view my activity :o)
      Re-paired the M400 but still no sync :o(

  99. Joe

    I live just outside DC and am a 25-30 mile a week runner looking to buy a first GPS/Activity tracking watch. I was sure the Peak Basis was the one I wanted until my reading lead me to the new (at the time yet to be released) FitBit Surge. The biggest problem I see with the Surge is heart rate accuracy. I feel like HR is the key to becoming a better runner and is really what initially focused my attention on the Surge.
    Through your reviews, and some other reading I am now looking at the Polar M400. The problem I see with that is that it doesn’t seem like the activity tracking is as accurate as the Surge. Additionally it looks to me that Fitbit’s software integration via iOS is much better than Polar.

    Do you agree that Fitbit has better software and do you think that should push someone toward the Surge from the M400? Also, how would you rate the M400’s activity tracking compared to the Surge.

    I really appreciate your reviews, they are very detailed.

  100. biker30x

    I’ve been using my M400 for a week, outdoor, treadmill. Accuracy good, GPS lock not bad and until today, sync wasn’t bad. Using an iPhone 5. Today EVERY sync has failed. It pairs, but after a minute or so, both the phone & the M400 say sync failed. I’ve re-installed polar flow & sync, forgotten & repaired devices repeatedly – still fail. It will sync easily when I plug it in via USB.

    Anybody got any ideas beyond trying it over & over hoping for a different result?

    Other than that, I really like the M400, and find it to be accurate, easy to configure & read & comfortable to wear. I’m coming from a Motorola Motoactv and REALLY miss having music on board and only one device with me – did somebody say there’s an expected Polar update allowing the M400 to control music on my phone?

    Any help on the sync issue would be appreciated.

  101. steve

    Hi, haven’t been able to resolve my issue of app and flow sync displaying sleep even though not worn at times during the day (white instead of grey lines) therefore displaying incorrect active and total sleep time. Have had contact from Polar thru FB and email and have suggested a few things but with no success. Has anyone any ideas or have this issue? Thanks.

    • Grant

      Steve, I have had the same experience. When I initially used the M400 (Christmas) it showed the grey lines when not worn. That lasted a week or two. More recently the only time it records the “not worn” grey hatching is when it’s plugged into the computer for charging.

      More generally, I’m still very happy with the M400 for the price. Syncing is sometimes an issue, but I suspect that’s because I sync with multiple devices; iPhone/iPad; it first tries one (last one used) and if the sync fails and I sync again, it then tries to pair with the other device.

    • Steve

      Grant, thanks, that is about the same time as the last update same when it started for me. Kind of over it now as I have tried everything but it is frustrating. Hopefully next update will fix it, cheers.

  102. Joe

    My apologies if this is a duplicate post. I received an error last night when I tired to leave the comment, however when I tried to post it again another error came up saying it was a duplicate post. I figured I would give it overnight and see if I saw my comment and try again.

    I live just outside DC and am a 25-30 mile a week runner looking to buy a first GPS/Activity tracking watch. I was sure the Peak Basis was the one I wanted until my reading lead me to the new (at the time yet to be released) FitBit Surge. The biggest problem I see with the Surge is heart rate accuracy. I feel like HR is the key to becoming a better runner and is really what initially focused my attention on the Surge.
    Through your reviews, and some other reading I am now looking at the Polar M400. The problem I see with that is that it doesn’t seem like the activity tracking is as accurate as the Surge. Additionally it looks to me that Fitbit’s software integration via iOS is much better than Polar.

    Do you agree that Fitbit has better software and do you think that should push someone toward the Surge from the M400? Also, how would you rate the M400’s activity tracking compared to the Surge.

    I really appreciate your reviews, they are very detailed.

    • I’d agree that the Fitbit produces more in-depth software than the M400. But, on the flipside, the Surge’s HR monitoring during activities isn’t that accurate (see my review).

  103. JS VT

    I have been using the M400 since the first week of November and overall I am very happy with it and think it is a very good deal for the price (I use the H7 belt).

    I have found GPS to be consistently accurate and have not had to reset the watch. I think I have had the first 10 – 20 meters track in error 2 or 3 times when I started right after getting the GPS lock OK. GPS lock is usually pretty quick but sometimes takes up to a minute. I try to wait another 20 seconds after lock before running. I have run in some nasty winter weather with the watch under a couple thin layers of clothing and GPS accuracy was not impacted. I also run through some woods – but they are hardwoods and at this time of year with no leaves there is little obstruction for the signal. I have not run in urban areas. I am looking forward to using it while cycling but that is a couple months away for me.

    The elevation is almost always starting at zero but I adjust elevation in Training Peaks anyways so not an issue.

    I also have used the watch for indoor workouts and with the H7 it has worked fine for treadmills, yoga, strength and rowing.

    On time stamp – the activities when uploaded to Flow show the correct (my time zone) time the TCX files for upload use GMT (5 hour offset from my time zone in eastern US). The time stamp for me has always been the activity start time and not the upload/sync time. I always sync using the USB cable and I don’t use android or ios app.

    In Training Peaks adjusting the time is simple so not an issue for me. Endomondo does not allow the time to be edited but the activity shows on the right day unless I am starting at 4AM (not going to happen). I uploaded a couple files to my old Strava account and they also posted with the start time albeit in GMT and I did not see any way to edit it. THe funny thing is that I also uploaded some runs to Runtastic when I was looking at their apps (since they support Windows phone) and the time stamp is the start time and adjusted to my time zone.

    So for me the TCX file is consistently uploaded with the start time and then depending on which platform I am looking at the workout in the time stamp may be accurate without editing (Runtastic), can be edited from GMT to my time zone easily (Training Peaks) or is posted with the start time in GMT and can not be edited (Endomondo and Strava).

    I wear my M400 24/7 unless I am going to be in a more formal business/social situation. The activity tracking seems very solid during non-workout time. When I remove the watch to sync or shower the activity “dial” in Flow shows that time as “Not worn” with the hash bars. The sleep tracking seems pretty accurate with the only issue I have seen being that my dogs have at times woken me up for more than 60 minutes and so the watch assumes I am awake even if I finally get back to bed for another hour or two. In general I use the activity tracker as more of a trend line (did I do more today than yesterday) vs an absolute measure of distance/steps/calories during a day so I am not to concerned if those three are not measured accurately so long as it is consistent. Having said that I found the measures to be in line with both a Fitbit Force and a Garmin Vivofit (both of which were replaced by the M400).

    I am not a big fan of the Polar FLow site and other than the activity tracking use other sites for tracking training. I do like the ability to customize the screens by workout type and usually use 2 data fields for the first screen so they are easy to read and then 3 or four on the next screens depending on what I am interested in seeing.

    As I stated at the beginning I think the watch is a very good value for the money but I do not use the phone apps so their utility, or lack thereof, doesn’t impact my opinion.

    Have fun – John

  104. biker30x

    New M400 user, I recently replaced my Motoactv which is finally getting too “glitchy” to be reliable. While the Motoactv more or less sync’d automatically via wifi with my home computer, it looks like I’ll have to rely on syncing the M400 with a USB cable.

    I saw a number of comments about slow GPS initial pick-up – so far, the Polar gets locked in much faster than my Motorola did. Then I noted Julian Middlewick’s concern about race times over training runs. With my old device, in a race situation, I would get GPS lock, start the work out (what Polar calls “recording”) and then immediately pause. I would do this in the chute with a minute or two to go before the gun and then “un-pause” as I crossed the start mat. While this maybe added a second to my time, I never lost GPS and was ready to go. With the Motorola, I had to do this, because if I didn’t start the activity fairly soon after getting lock, it would reset and I’d have to re-acquire.

    This makes me wonder – does the M400 have any kind of max pause duration that will close & reset if you don’t resume? OR do I need to do this at all – will the M400 basically idle at the “GPS OK” screen, holding GPS lock for 5 or more minutes until I press start?

    BTW, the % acquired display is SO much better than the Motorola’s old 3 minute countdown where lock could happen (or not) at any point.

    I’ve also found GPS accuracy pretty spot on – even showing spots where (to test it) I ran across the street & back or sprint for 1/2 a block or so – the path & pace both reflect those short term deviations. Pretty cool! If only it had 16 or even 8G of music storage! Oh well.

    • Henry

      “This makes me wonder – does the M400 have any kind of max pause duration that will close & reset if you don’t resume? OR do I need to do this at all – will the M400 basically idle at the “GPS OK” screen, holding GPS lock for 5 or more minutes until I press start?”

      From my personal experience with my M400, it will stay forever at the “GPS OK” screen until you restart/battery dies.

      I took it to cross country skiing in the morning last week, paused it to re-wax and have lunch, then 2 hours later, it was still at the “GPS OK” screen and I was able to start activity right away.

  105. Joe Adamson

    New Android Flow app update release, and a firmware update for V800 and M400 as well to improve syncing. Fingers crossed this fixes issues some have experienced.

    I have noticed recently that the Flow app in android has started showing more information, e.g. giving a percentage to activity target (where in past it just showed 0%) as well as suggestions for different activities you could try to meet your target and how long you might need. I apparently only need 40 minutes of squash, 1 hr 56 minutes of gentle dancing, or 3 hours 59 minutes of slow walking.

    Very happy so far with everything. One thing I was frustrated with was I did not buy the HRM strap package as I thought my Adidas Bluetooth Smart Strap would do the job, which it did but unfortunately not for the Fitness Test functionality as it does not record/transmit HRR data. I have since bitten the bullet and bought an H7 and now very happy!

    • MikeJ

      Thanks for the heads-up about the update, just finished updating my watch and the work computer (where I sync by cable), also updated the android app. I haven’t tried any app sync’ing yet and may wait for a bit with that option.

      Interesting that the Polar update site isn’t showing this latest update yet, could be due to time zone differences or something.

      In any case, I’m happy with my M400 and it works well for me while using the cable to sync it.

    • Stefan A

      any other improvements except sync? I´ve never had problems syncing with iOS app (the app is still at 2.2.1)

  106. Joe Adamson

    There was an update put out by @polarglobal about two minutes after I tweeted them to ask what was in the update. It says that the android app release was to fix “data visibility issue”. The M400 and V800 firmware update was for “improved sync”. Given the limitations of Twitter there may be more.

  107. spounz

    still sync issues with this update : ‘sync failed’ (trough iphone and bluetooth).

    polar sucks !

    • konradsa

      Delete the app and all data from your phone and reinstall it (they posted this advice on German Facebook page). Also delete the Bluetooh pairing and re-pair.

  108. Steve

    Hi, I need some help understanding how the Sleep analysis works as per DC’s images in review. In my web sync summary it says 7 33 sleep last night but in Activity Overview (underneath man resting) it is 7h 15 and some days it is a bigger difference. Not sure of why as DC’s example shows different times as well in review. The mobile app has different time again. I presume the app starts monitoring after midnight and sync before and after midnight. Would really appreciate if someone could take the time to explain how it works. Much appreciated. Thank you in advance for any help.

  109. 1LightningFan

    What’s going on with Polar? For the last 2 or 3 days when I try to sync my M400 with the mobile app I get the message that I need to update the watch. Ok, no issues there… So, I plug into my PC with a quality usb cable and the Polar FlowSync webservice is unresponsive. Even when I try to open the program by double clicking the FlowSync icon I get an open window but little more. I uninstalled and tried to reinstall only to find that the Polar website won’t let me download the program now. I tried to contact them using their 24/7 chat only to find that they are offline (not 24/7 in my book). Is Polar in serious trouble? I’m getting a little worried due to the service (or lack of service) I’m seeing (or not seeing)…. When can we expect a reliable mobile app, a reliable web service and reliable customer service? I’m really getting discouraged here….. The M400 watch is great. I can’t say the same for the mobile app and web service. What good is the watch if you can’t access the data?

    • Not sure why the download icon isn’t showing on the M400 page. No worries though, it’s the same software as the V800 and Loop, so you can use the icon there: link to flow.polar.com


    • 1LightningFan

      Thanks for the advice, but still no dice. I tried the download link on the V800 page and I get the same “could not be downloaded” message. I also have a Mac desktop which I had previously installed the FlowSync app to. When I open the app on that computer I don’t get anything either. The app is totally unresponsive. I thought it may be some issue with my internet security on the PC, but since it isn’t working on the Mac either that rules that idea out. Is anyone else experiencing this issue? The latest version of FlowSync is 2.3.8, right? That’s what is attempting to download but fails. Thanks again.

    • I think you’re running into a n issue related to your network or something else. I just downloaded the file from the site with no problem. I’d try rebooting your router, and failing that – giving up for the night and seeing if your ISP can solve their issues.

      (By giving up for the night, I mean going and finding ice cream)

    • 1LightningFan

      That’s great advice (the ice cream part). I’ll keep trying… starting again tomorrow. I left a message on the 24/7 Polar chat line. Maybe I’ll hear something from them soon. Thanks for the help.

    • MikeJ

      Just as an “all is not lost”, a few days ago I was able to update the desktop linking app, and then the M400, and all is well as long as I sync and upload via the usb cable. The android app still has issues but I can work around that.

      My opinion is that things are improving step by step.

  110. John

    the newest download worked for me 5 minutes ago MAC, USB and a reliable DSL. So…. not the Polar site this time.

  111. Wesley Forbes

    I just got my M400 last night! Followed the directions, plugged in the USB cord, connected to my computer, hit the sync button and everything worked perfectly! It asked me to sign up for an account which I did and let me know that there was a new update, 1.3.? (I don’t remember) which again worked fine. I was even able to get a GPS lock while in my house! I also installed the Android App to my phone and after signing in, it knew who I was already and was ready to go.

    I took it on my run this morning after pairing it with the H7 monitor and everything went smooth. It told me to be still while acquiring GPS, and once it did, I was off. While running I kept checking it out to see how my heart rate was doing and things looked great there as well. Showed my zone and everything!

    Once I got back and hit the back button then held the back button for the time needed, it recorded my activity. I then plugged it in to my computer and synced it and my activity came up on the right day and hour as when I actually did the activity. I then wanted to check out the app on my phone and see if the activity was on there since when I recorded the activity right after my run, my phone was in my pocket since I listen to music. The activity was not on there, which I thought it would be. I then opened up the App (which was open during the activity) and held the back button again, and it did sync up with the app and upload it! Now, I am not altogether sure that everything went in all correctly but it is there and on the right day and time.

    I just wanted to let all new users read that despite posts of things not working correctly and there being problems, Polar may have gotten it right with this last update, and I look forward to all the new features that are planned down the road. So far so good!

  112. Stephen

    I’ve just connected my (fantastic Garmin-smashing) m400 after a week or so away from computers and downloaded the latest update.

    Now I’ve got the watch back on I find that the only update is that the data for my previous runs is much more limited – it used to show a little graph with times / pace per automatic lap, now shows nothing more than the summary screen. Great update!

    Anyone else found the same?

    • -running-


      maybe this was not even releated to the update.
      Memory is limited, so Polar removes details of session once memory gets filled up.
      So new sessions contain all details, and the older sessions grow details are getting purged. But I have no idea if this is documented some place


    • Magnus Helander

      Hi Stephen,
      maybe you have already figured this out but when you flip through the days in the Diary on the m400, and you select a workout, you then flip to the “Summary” screen with best lap / average lap – this is where you press the red start-button to get the graph and for each lap see duration / heartrate and pace max/avg by pressing the red start-button repeatedly.

    • Stephen

      Thanks Magnus – yes, that’s exactly why I was soon before the update but now the best/average screen has been removed from all runs including most recent (not many on it yet) and the red button does nothing. It’s odd – I could access the screen on all the runs immediately before.

    • Odd indeed – the best / average screen should be there….

    • Stephen

      I asked Polar via Facebook and they responded.

      Apparently, when you upgrade the firmware, the training data is removed from the watch and then restored but only partially – lap information is not restored. No explanation as to why this would be – my M400 was up to about 8 hrs worth of training, nowhere near the limit.

      The lap info on Polar Flow remains intact and for runs after the upgrade lap info is accessible on the watch (until the next upgrade…?).

  113. Anders

    Just wanted to drop by and thank you for the in-depth review, bought the watch after reading.
    I’m sort of a novice runner, who’s training for his event (a half marathon), and the M400 feels like the perfect running companion. And also, I think this is an outright steal in terms of price/features (paid 165€, strap included).
    My other option was the FR 15, but to me the M400 felt like the more modern watch in terms of look and feel, (I’m a designer by profession and looks do count). The Suunto Quest was also something I was checking out, but Suunto in general felt a bit pricier for models which are essentially last generation.

    To help fellow readers make a decision, here’s my list of features that I absolutely had to have when buying:
    – Built-in GPS. Wanted to get rid of my phone for my runs. Not too many options in mid range watches.
    – Optical HRM wasn’t an option (I Live in Finland, which can mean down to -25°C on my winter runs, and sometimes have to wear the watch on top of my jacket to avoid exposing bare skin)
    – Customizable screens. To me, should be mandatory for anything that calls itself a modern wrist computer, no excuses in 2015.

    Few thoughts so far:
    + The GPS is exceptional, and compared to my Lumia 925 + Runtastic, more accurate and in familiar trouble spots, like running under certain bridges, not a single drop on my Polar. I live in the center of the city, and the first time the GPS was horribly slow in getting a lock. Now, I just let it sit on my apartment balcony while I tie my laces, and it’s good to to go in seconds when I get outside. Other times, the caching really works.
    + The screen and contrast is great, and the always-on backlight is a great feature, compared to my older, budget-priced HRM.
    + Setting up training targets in phased mode is a huge plus. Just add my usual training targets for running, weight training, etc. into my favourites, and can just go from warm-up to main workout seamlessly, without even having to look at my watch. And you don’t even have to have them in your Diary, which means you can mix things up on the go, if you feel like the planned workout for the day feels boring.
    + The process for setting up the customised pages for sport profiles is quick and easy. I just wish you could using multiple profiles of the same sport. Would make customising the screens for different types of runs more convenient.

    – Polar Flow is still a work in progress. All in all, it works great, but some minor kinks are getting more annoying by the day. My main gripe is setting up a training program is painfully cumbersome and outright stupid. And the fact that if you’re already a polarpersonaltrainer user like me, you can’t import anything from there! At least not yet.
    You have to manually input every training session, and having a training target already in your favorites does not speed things up. Adding multiple dates using the same training target in one go is not supported. And the process is very counter-intuitive:
    – You click a date on your diary, and in the second page you select a favorite workout. And yet, you still have to bring up the calendar, and select a date to add, and manually type in a time of day (why is time of day even a mandatory field?). I would assume the system would be smart enough to autofill all the required fields, since you are already accessing it through a specific date on your diary…or when the calendar pops up, you could just click on multiple dates in one go.

    Anyway, excited about the product, and even found the activity monitoring fun, even though the algorithms are wonky sometimes (burned 200 calories walking 200m the other day). 😀

    Awesome site, keep up the great work!

  114. Lesley

    Hi Love your reviews. I bought an m400 yesterday – set it up. Went outside had a heart rate and it got the GPS signal – great but I wasn’t going for a run so stopped it. This morning went for a run and it didn’t pick up my heart rate. My app on my iPhone did but nothing on the watch.
    What am I doing wrong? Thanks for any help

    • It’s likely because your iPhone is blocking the connection to the HR strap. With Bluetooth Smart, you can only have one device connected to the sensor at a time. So if the iPhone (or an app on it in the background) connected to the strap, the M400 would be unable to.

    • Kale

      Exactly! I have a bluetooth speaker at home, and when I have friends over and they want to put on their play lists I have to disconnect from the speaker before my friend can connect his to play. Same concept here. That ‘threw me for a loop’ the first time I had that problem too.

    • Lesley

      Thank you! Now if I could just get it to sync without having to plug it in I’d be a happy runner 🙂

  115. Wesley Forbes

    Quick question: Is the M400 supposed to sync and update the app through your phone automatically, or do you have to manually do it every time?

    • Kale

      AKAIK, It will not do it ‘in the background’ (automatically) you have to prompt it to sync each time. A quick trick is to just hold down the ‘back’ (lower left if looking at face of watch) button and it will begin syncing.

  116. patricio

    Hello people.
    I used to train using micoach so i understand the concept of pace zones and its a good concept but what i really don’t like of the micoach’s method and now Polar’s is the restrictions in the creation of each zone. You can’t create a pace zone for example from 6:00 min/km to 6:30 min/km like in Garmin because the software tells you there’s a limitation of at least 1 min/km difference between each zone BUT you cant either create a zone with less than 1:45 min/km…i don’t know if is a problem in the web or that’s the way it was created but in my opinion that lack of freedom make more difficult to create complex training sessions.
    I dont understand why such restrictions. Ray do you have at least a theory about this?


  117. KilkennY

    Rungap app for IOS was just updated, so that you now Can import from Flow- and Then export to Strava, Runkeeper, garmin Connect, polar personal trainer etc.
    This is so great, that we now Can do it alle from the phone and with only a few clicks 🙂
    Just hope it all works 🙂

  118. Kale

    Hi Ray,

    I’m trying to save a ‘favorite’ route and it says ‘Will not be synced to training device’ I’ve tried to save, sync, etc. but nothing seems to change it. I ‘star’ the route and go to my ‘favorites’ page and it gives me that error message at the bottom of the rectangle. Sure enough it isn’t listed on my M400 when I go to favorites.

    Are you familiar with this?

    Thanks in advance,


  119. johan


    does anyone of you has/had any sync issues today after updating to 1.3.3 when using the Polar FlowSync (Desktop version)? I came back from training today, uploaded my activity – although it took longer than usual – and launched the firmware update to 1.3.3. It took about 20 minutes and it didn’t gave me the final window that the update to 1.3.3 was successful. The whole process got stuck at the section “Synchronising Activities/Trainings”.

    I’ve done already a reset of the device twice, but it simply doesn”t sync new activities.
    Is there any other option left beside of the “restore to factory settings option” or is this a general issue that syncing simply doesn’t work? I’ll probably wait until tomorrow to check if the same issue reappears again

    BTW. There was a message today on Polar Flow Website that they updated Polar Flow portal.Maybe this has something in common.

    Thanks for any suggestions or feedback.

    • JS VT

      I got my workout to sync (indoor so just time and HR) but when I went to the diary to see the detail no HR data was available even though on the M400 it shows time in zones and min/max. Exported TCX file and that does not have any HR data either.

      Synced using USB cable.

    • Simone Pillon

      Yes I’ve had simliar problems yesterday. The watch synced only the daily activities using the App and not the run, no matter what I tried. Attaching it to the PC it apparently synced my run but looking at it on Flow website it seems to lack any GPS/pace data. A soft reset didn’t solve anything.

    • Simone Pillon

      Okay issue partly solved: this morning syncing through the PC it worked, yesterday’s run activity shows correctly on Flow website. The app still doesn’t sync though…

    • Joe

      I have also had issues syncing. Often it will not work at all, after a few minutes the watch says syncing failed. Usually if I try it again it works, but sometimes I need to do it three times. Very annoying.

      Do we think this is a firmware issue? Has anyone had this issue before?

      Any other suggestions?

  120. Dannigirl

    OK, I have a GF 15. I was thinking about getting the m400 or the G220. I do yoga, spin classes, 5k’s, and pilates. I want a watch that accurately counts my calories. Should I stick with what I have or are the M400 or G220 upgrades? Thanks. oh yeah, if I order through your Amazon link, will it still benefit you? I love my prime shipping!

  121. Danni

    OK, I have a GF 15. I was thinking about getting the m400 or the G220. I do yoga, spin classes, 5k’s, and pilates. I want a watch that accurately counts my calories. Should I stick with what I have or are the M400 or G220 upgrades? Thanks. oh yeah, if I order through your Amazon link, will it still benefit you? I love my prime shipping!

    • I’d go with the M400 if I were you. You’ve got slightly more flexibility on calorie burn metrics/modes than on the Garmin FR220, for gym activities.

      And yup – the Amazon links help support the site. Cheers!

  122. Noë

    Hello, DC Rainmaker, Thanks for your review. I am doubting if I will order a RC3 GPS or M400… I really like cycling and therefore I would like to use the cadence sensor on my bike. Do you think this cadence sensor for cycling will be included in the M400? Or will there only be a footpod for running?

    Next to cycling I like running and speedskating. So I am still thinking which one too choose…

  123. Kale

    I ‘chatted’ on line with a Polar rep. this morning and found out they have currently have a ‘usage break’ (is the term they used) while they try and fix the problem with syncing through ios app.

    They are working on ‘Flow web service and FlowSync/Flow app data transfer’ and there is no ETA on when it will be fixed.

    Just thought I would pass along the info……

  124. Wesley Forbes

    I am glad to see that they are working on something. I jogged this morning and attempted to sync to the Android app, but it did not take. The activity was on my watch and when I went to the PolarFlow website, it was also on there, just not on the app.

    Several hours later, I checked the app and it was there….??

  125. Mark Hughes

    Yeah sync seems to have been utterly broke today – my run from lunch time didn’t sync at all via android across several attempts. It finally did sync, after a fashion, later in the day, but the GPS data is all missing from Flow, I just get a heart rate / pace graph with no map. I can see the map in the app on the phone, though, so the data does exist somewhere… Hopefully it will turn up soon.

    It would be really good if FlowSync allowed export of TCX direct from data on the watch, so when Flow isn’t working you can get hold of your data and analyse with the tool of your choice. I don’t know if other watches do this, but it would be a very good feature for any of them to have – this requirement that you have to use their web application to get to your own data is tiresome, particularly as the reliability isn’t all that great (and from what’s been said, it seems Polar is not alone in having trouble with their online platform availability being more patchy than one would hope!).

    I’d happily write the code myself to translate the data if I could get any idea how to talk to the watch over USB…

    • Mark Hughes

      If anyone else has this exact problem, I managed to force the android app to resync the training in question by adding a note and telling it “how I felt”… After doing that, the map and lap data now allow appears on Flow web too. Yay!

    • Simon Anthes

      Go do a search on GitHub for “Bipolar” – this does pretty much what you want, so no need to write the code yourself 🙂

    • Mark Hughes

      I love you! Thanks, that sounds perfect!! And open source too so I can play… Woot!

  126. Jesse

    Does Polar Flow have a way to track shoes and mileage the way that Runningahead.com does?

  127. Melanie

    I currently have a Garmin edge for cycling and I would like to get this watch… I would also like to get a heart rate monitor. Should I get the heart rate monitor that comes with the m400? Will it work with my garmin edge? Or should I forgo the polar heart rate monitor and instead get a garmin heart rate monitor? Will I need a different heart rate monitor for each device? Thanks!

    • Melanie

      Or since I already have the Garmin edge should I just get a Garmin watch? I really like this watch though….

    • KilkennY

      Hi Melanie.
      Garmin uses Ant+ and Polar BLTE.
      My advise would be to get a Dual band HR strap like the wahoo tickr or tickr X. It will work with your polar watch, your Garmin and your phone.

  128. Menno

    Hi Rain, Thanks for the nice review! I think you made a miscalculation in the battery life comparison between v800 and m400. 8 or 50 hours? The difference is huge!

  129. Steve

    Hi, is anyone else having problems with sleep time on M400 as todays sleep time started at 4pm when didn’t go to sleep until some 6 hours later??

  130. Sandijs

    Love my M400, but have one big problem – can’t sign in Polar flow app on my Iphone 5s. I get – “polar.com/flow is currently no available.Please try again later”. Tried “later” for almost two weeks now and nothing…
    Tried on my old Samsung S3 android and all works. Tried reinstall my iphone app, nothing…

    Is it only problem on my Iphone or is there problem with Polar flow Iphone app???

    • Kale

      My app works, but I cannot get my iPhone to sync with my M400. This is pretty pretty annoying. Ever since I upgraded to this 1.3.3 firmware it doesn’t recognize my M400 when I try to pair it.

      Ray, I have been writing Polar and calling (usually on hold for 20+ minutes until I give up). Can you reach out to one of your contacts at Polar and see what the status is on a new firmware update to cure this Bluetooth probelm?


  131. Geoff

    Hi Ray,

    Will doing activities like boxing while wearing the watch potentially damage the internal accelerometer?


  132. advaita

    hi you have a great site and i like the way you write=)
    i am a person losing weight. i go to the gym, bike and swim .
    i like the tom tom multisport becuase of its “no chest strap.”. and because it is cheaper than other thriathon watches
    yet i also like this one

    what do you recommend for me

  133. GAB


    Thank’s for the detailed review.
    Question about first battery charging: need format the battery to ensure better battery life later.
    It is right – Battery is completely finish charging when is no batt. sign any more. How long shall I live it connected.

  134. Jo

    M400 (blue line) vs RC3 (red line) GPS tracking:

    link to gpsvisualizer.com


  135. Anders Bech Mellson

    Thanks for another great review!

    Does Polar have similar training plans such as those found on the Garmin Connect platform?
    Eg. training plans included suggested heart zones for various distances.

  136. Claire Pruitt

    Thanks for your review! I’m considering buying this watch along with the footpod for accuracy since I run on the treadmill quite a bit. I read in your review of the Garmin 220 that you need to calibrate the footpod (using math). Is that required with the Polar? And, is it difficult? Thanks.

  137. Enrico

    thanks for the excellent review. I’d buy.use this M400 if it has the possibility to drive me when exercising… i.e. is it possible to create a training program via Polr Personal Trainer web site and load it in the M400 rto receice directions? Should I buy for this another Polar product like RC3? Thanks in advance.

  138. Alex Masidlover

    I’m currently using a Garmin FR60 (!) as my day to day watch then with a Mio Link to track heartrate and HR Zone during swimming – it seems to work reliably when the devices are next to each other (same wrist and same way up).

    Sadly I killed one FR60 with a few months of day to day wear which including swimming 3 hours per week (even without pressing the buttons underwater) – Garmin did replace it under warranty… I suspect the new one may be going the same way (started fogging slightly) and am looking at candidate replacements as a day to day watch that can record my HR during swim sessions. I use a 310XT for the rest of my training, but its too bulky for day to day wear and would look ridiculous when swimming…

    Has anyone tried using the M400 (or V800 as I guess the results would be similar) with a Mio Link next to it just under some generic profile that leaves bluetooth HR enabled?

    • runnershigh

      I use the m400 combined with the mio link – but not for swimming; just running. If you connect the mio link via bluetooth with an device (for example with the m400) then you can’t connect the link with a second device by bluetooth again. You can connect each one device by using one transmission-protocol. I hope I could help you so far.

    • Alex Masidlover

      Thanks for that, I guess the question is then whether the signal transmits through 1-2 cm of water reliably; in principle it should be very similar to ANT+ as its the same frequencies (or near enough that the absorbtion of RF in water will barely change) – the question is whether the antennae in the two devices are as effective as the FR60 + Mio Link combination which does work under water…

    • runnershigh

      In comparison to my FR110 (ANT+) the m400 (BTLE) receiver seems to be more sensitiv by air. On the other hand, I would be careful trying the m400 under water / for swimming. I am not really convinced that the m400 is that much solid in that case…but I never tried.

  139. Ramachandran S

    Thank you for an excellent review.

    I have a question

    Can the Bluetooth foot pod and the H7 Heart rate monitor connect to the M400 at the same time? Can it track the HR and foot cadence in the same session?



    • There is an update coming for the M400 that will allow users to utilize the Bluetooth Smart stride sensor with their watch. You’ll be able to see both heart rate and stride sensor data at the same time – Mike @ Polar USA

  140. Not to be found on the Polar-forum but is there anyone reading here having the following issue with the M400?

    Last week I bought the M400 to replace my Garmin FR 310XT.
    Created a workout (10x200m interval) and started off with it yesterday. After the warming up and 2 quite fast 200m’s and scrolling through the screendata the Polar completely restarted, losing my data of my run so far. Started again with the same workout and after 7 200m’s the same happened.
    Now started a run, didn’t touch the buttons anymore and ran 3km’s towards home, resulting in, according to the polar, the longest distance so far etc. 😉
    Unfortunately no data was saved from my runs before the crashes happened. Anyone experiencing the same issue? Will this be a software or hardware-problem?

    So far, the 310xt can’t be sold yet.

  141. Nigel Deutrom

    First HRM style watch and absolutely love it. I use it to track all my HIIT, Boxing, Cardio, running and cycling that I do.

    Having just taken up running. I have been reading on on HR zone running and the types of running that you do to target specific HR Zones,. At the moment I just run anything up to 10k and it logs the time, distance and HR Zones used.

    Should I target specific HR zones? and also should I change the zones to the Karvonen method?


  142. tobias

    is it possible to see gps coordinates in UTM unit instead of minutes and seconds?

  143. themightye

    First of all, thanks for your wonderful writeups on the various products out there. I was torn between this and the Garmin Forerunner 220. I have found this watch to be great, easy to use, records my runs accurately, and allows me to capture my progress. From Toronto, there have been some mighty cold days which have led me to run indoors on a treadmill. Just waiting for the update.

    I have had no issues with the GPS, and the watch is not so bulky I feel it is a hinderance. Quality so far is good. I do not wear it when working out, just for runs and on days when I want to check my general activity levels. For the price, good choice. Especially as a new runner on the couch to 5k program. Just finished my 6th week!

  144. Joshua Schiffman

    I’m currently using the Timex Run Trainer v.1, but it’s been a little buggy lately and I’m thinking of making a change. The M400 seems like it might be a good fit, but I have a question or two and I’m hoping you can help.

    I’m one of those walk/run “interval timer” types. It sounds like the M400 can do simple intervals, which would work fine. Does that integrate with the display screen? In other words, while I’m running, can I see not only my pace and distance but also the amount of time left in my current interval?

    I apologize if I’ve missed the answer to this. Thanks for your help!

    • runnershigh

      If you use a time-based interval setting then you will show a “countdown” to each interval task you have set before. If you set distance-based intervals then you only can show the distance left you have to go.

    • Joshua Schiffman

      I’m not sure I made myself clear. I only use time-based intervals, but my question is more whether I can set the display to see the time remaining (as you suggest) AS WELL AS my pace and distance. In other words, can I customize a display that includes ALL of the following:

      1) Pace
      2) Distance
      3) remaining interval time

      I hope that makes more sense and thanks for the assist!

    • runnershigh

      As I remember correctly you can add in flow (online) at the training diary a specific training. You have to create a training with intervals by using “speed/pace zones”. Now you can see during your workout your current pace zone, but no current pace in units (km/min etc.). I think the polar interval training feature leads on heart rate or -pace zones and so the exactly pace itselfs is not the main idea for this.
      If there is a solution for your needs then I didn’t know a better way as to accept using pace zones. Sorry.

    • Joshua – You can indeed see the information you are looking for during an interval phase. You’ll likely need to update the sport profile you use to see the information however. You can very easily change those display settings by signing into your Flow account and then clicking on your name on the top right and then selecting ‘sport profiles’. It will be here where you can update the settings accordingly. Remember to sync your watch to the Flowsync software after you are done! – Mike @ Polar USA

    • runnershigh

      I think Joshua know how to edit sport profiles in flow. But I see no solution to do so because the “interval timer” has its own specific view.
      Did you mean Joshua has simply to change the view by button after starting the interval program on the m400?

  145. runnershigh

    I use the m400 now about 4 month. One thing I am worry about is, that it seems not possible to show the pace on an single automatic lap. Even it is not possible to let show the lap-time of an last automatic lap. Only by pressing the lap-button (manual lap) specific data fields will be filled on the display (average last lap time, average lap time to a current lap).
    So why are such many data fields only working with manual laps?

    @all; what are you thinking about this issue? Is there any senseful explanation for this?

  146. William Nunez

    Had this device for 2 months and used 3 hours a day 6 days a week. Has bee flwless till today

    Wil not charge on any USB cable. Any ideas>

  147. Krzysztof

    Thanks for great review.
    Three things I would like to ask about:
    1. Phased Training
    If I set up phased training on Polar Flow, then transfer it to M400 I am followed by watch through every phase of training. e.g. Warm-up 15 min+Work 15 min+ Cool-Down 15 min. I switched off the automatic laps to make sure I will get the laps only according to my phased session. But unfortunately it is doesn’t work like that. I didn’t get any laps at all. Do I do anything wrong? Or M400 software is set up this way. It looks like the one solution for this problem is do the laps manually when I go to the next phase of training?
    I was charging the M400 yesterday for about 2.5 hours but I did not see charging complete to be displayed on my watch. What is the length of time to charge fully M400? Or my watch is faulty?
    3. Training Benefit Feedback
    I changed the HR zones to free and I set up them to reflect my training needs. I was exercising for exaple in 70% of my HR max for longer period and it was my mainly first zone for 30min and 75% for 15min 2nd zone. At the end of the workout I got a massage on my M400 saying taht it was recovery session. But two days ago was doing the same training session and I got basic steady state training message. It looks like that description of the summary of training session is based on HR zones only. It means eg if I set first HR zone from 90 bpm to 180bpm and I will be exercising near 180bpm the feedback will be the same like for 90bpm to 114bpm – that it recovery training?

    • Krzysztof, you encounter the same thing as I am lacking with your remark 1:
      I would expect that the workout-intervals would be seen as laps, but unfortunately the M400 doesn’t do this, so you have to press the lap-key every time, or put it on automatic laps. This is different behaviour to what I encounter with my Garmin 310xt.
      Also I’m missing the warning beeps prior to the new interval. I might solve this by adding an extra ‘lap’ in the workout of 5 or 10 seconds just prior to my intervals, when I will also then press the lap-key.
      2. Charging: Guess the M400 doesn’t show if charging is completed. Only if you unplug it you might see that it charged to 100%.
      With 3 I can’t give you any help.

    • Krzysztof

      Thanks Dick,

      Three days ago I changed my Forerunner 610 to Polar. And I am bit disappointing.
      One thing only rewards this decision is HRM Bluetooth. I can use it with othe 3rd party apps.

      Is anyone from Polar reading our points, and taking it into theirs consideration?
      It would help them to make their products working much better and be more competitive.


  148. Marcel

    Hi Krzysztof,
    I am thinking of doing the same thing, as I am tired of my Garmin FR 610 battery problems and auto-resets.
    However, I do get the feeling the M400 is a good replacement. What is it exactly that you miss from the 610?

    To me, it seems like it has everything I used regularly, and then some, now that I can get messages from my mobile (if that supports Android). I asked a couple of questions, and at Polar support (which replied pretty fast, by the way) they said s3 footpod support, to measure distance in tunnels, e.g. (that must also mean: measures distance with the footpod) would arrive end of Q1 (march). Also: they are planning an export feature to Strava, which should arrive through an automatic update.

    • Marcel

      by Strava-export I meant a synchronisation feature.

    • Marcel,
      I miss customization mostly. The other thing is that the intervals are not seen as a laps and there is no thing such a training benefit based on heart rate but rather, it is related to HR zones only. FR610 training effect is based on HR no matter how you set up your training zones.
      Overall I thing this is good watch, but some of the functions should be easier to switch on or set up e.g. switching back-light on during the training or moving/skipping next training phase or luck of audio sound before ending each phase.
      I miss vibration alerts as well. But this is not big deal for me.
      I like activity tracking, fitness test and running index and the way HRM H7 works. I think it is more stable and more comfortable then Garmin’s HRM.
      I was using Garmin products for over 5 years so maybe that’s way this is a big change to me with all set ups and the way it works.
      I was looking for watch which allows me to track my activity and to track my running progress and to be water resistant that I could take a shower with it on, for good price.
      I think I got everything what I wanted.

  149. Callum Furey

    Does anyone know if the watch band on the white m400 is smaller than the black model?