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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. David

    I had rust / corrosion problems after only 2-3 weeks of use. No idea if it was my sweat or some water that had got in behind the cover…

    However, I was very impressed with Polar’s service! I’ve never had such a positive warranty experience.

    I contacted Polar (in Sweden) and they apologised and asked me to send it to them. They fixed and returned the unit within the same day. To me it looked like the new USB plug was much sturdier in comparison to the one that was there before, but it also looks exactly the same as that in DC’s picture above so I’m not so sure.

  2. jamey Ward

    I think the answer to this would be yes, but can I pair the M 400 with either my Mio fuse to avoid using a chest strap? I would think so since it’s ANT+ and Bluetooth. Thanks for any help

  3. Helena

    Hi there
    I’m running my first marathon next Sunday and bought M400 last week – it’s my first GPS watch. As far as I’ve read, it’s supposed to have good GPS accuracy. My watch, however, seems to be having trouble with it. As long as I’m running under clear skies, it’s perfectly fine but as soon as I run under a tree (and I don’t mean a thick forest but just a random tree in the center of the city), my pace plummets. E.g. today, I was running at a steady 5:30 pace but when i passed a tree, my pace dropped down to ridiculously low numbers, such as 10:00 or 15:00. It happened quite a few times over a 45-minute run and my average pace can’t be trusted in any way.
    As I haven’t got any previous experience with GPS watches, I don’t know if this is the way they’re supposed to work. If yes, I don’t really see how they can be much use :) Or can it be that my product is somehow faulty? Thank you so much for any comments or advice! :)

    • Ricardo Martins

      There’s no GPS watch in the world that will be accurate near high buildings unless you would like to run with a 10 meter antenna on your head :P Some people complain about the GPS accuracy of the watches, but they forget that you are not gonna be landing a Boeing based on the GPS accuracy of a watch, its meant for running and for running is good enough.

      I have both a M400 and a V800 and the V800 is EXTREMELY accurate, having said that running near high buildings sometimes you see expected inaccuracies. If you have extra 160 dollars, just get a v800 and return the m400. In my opinion is the best watch in the market at the moment, aside with Garmin 920xt.

    • Pieter

      Did you update to latest firmware!

    • Mark Hughes

      The instantaneous pace is kinda all over the place on every GPS device I’ve ever used – but the overall average and lap average pace can be pretty good on the M400 so long as you have the latest firmware installed. The GPS accuracy got far, far better with the latest firmware – before that it was highly affected by just about anything being nearby, now it’s on a par (for me) with most other GPS devices – not amazing, but good enough, and much more consistent.

      Make sure you sync before running – it downloads assisted GPS data that helps it locate you and be more accurate when starting out, but that data is only valid for 3 days at high accuracy.

      With that and the latest firmware, I’m getting good results consistently from my M400 now.

    • Helena

      Alright – thanks for your comments :) I just really didn’t know what to expect from a GPS watch since it’s my first. The retailer suggested I restart the watch and in case it keeps behaving like this, take it to be checked by Polar guarantee team. I’ll try the firmware update thing before each run as well.

      Am I right to assume that the accuracy should be better in the winter, with no tree leaves blocking the signal? :)

  4. Kale

    Hi Ray,

    It’s me again….I’ve discussed this before and have been communicating back and forth with Polar with no solution yet. I have been using the watch 3-4 days/week since February with almost no problems at all. As soon as i bought a bluetooth set of headphones I keep dropping the heart rate about 10-30 minutes into a workout.

    It ONLY happens in the gym, and will not happen when cycling outside.

    Ray, is there ANY chance that the bluetooth headphones are interfering with the H7? Polar even sent me a new H7 and it worked for 1 workout in the gym, but the last 5 workouts, my HR has been interuppted anywhere from 10-30 minutes into my workout.

    I have loved this watch since February, but now it’s becoming VERY frustrating……..

    PLEASE HELP with any possible solutions or explanations of why this is happening now!

    • Unfortunately I’ve never heard of anything else like this. The only other times folks see sensor interference is with WiFi, but it usually has to be very near and very strong.

    • konradsa

      Kale, did you try using the Polar Beat up on your phone instead of the watch as I suggested above? That’s my workaround for this problem, works like a charm, even though it’s kind of sad that you can’t use the watch for its intended purpose.

    • Kale

      Thanks Ray, I’m truly baffled why it does this. I have been going to this gym for months with no problems with standard wired iphone headphones, and as soon as I switched to the bluetooth ones these problems started. Happened 3 times last week. I’m going to try it today with the iphone headphones again to rule out that as the problem.

    • Kale

      Konradsa, thank you for the suggestion, but this does defeat the purpose of the watch. I wear mine while I lift weights and my heart rate typically depicts when I start my next set and I don’t want to look at my phone each time, I just want the watch to work the way it’s intended and has for the past 6 months that i’ve been using it…..I’m in communication with Polar trying to determine the problem, I am not happy right now with this…..

  5. jamey Ward

    Ray, can the Polar M400 Pair with a Mio Fuse vs a chest strap? I would think so since it accepts Bluetooth? Thoughts?

    • Jason Oltrop

      I’ve successfully used a Mio Link with my M400 since January.

      The only shortcoming is that the fitness test function will not work with the Mio Link.

  6. Amil

    Hi Ray and compliment again for your blog, simply the best. I bought the m400 thanks to your superb review. After a stop of a week due to a bad flu today I used it again and compared it with iPhone 6 with runtastic. The final results give runtastic 400 meters ahead in a run of just about 9 km. I’m copying below both path
    link to flow.polar.com

    link to runtastic.com
    Apart from a 12 seconds longer run recorded in RT, so let’s assume I did about 50 meters in that time, still a final distance difference of about 350 meters is acceptable? I know it well might be iPhone + RT might be wrong (though I now the path and I think it is not). I understand that my path is really hard, being in the very center of Milan and passing in small street and under some skyscraper area, but what should I expect in such a path? Admittedly the pure trace is not even bad.
    Anyhow I’m tempted to return the m400 and buy the v800 since I love all the other polar features, but gps accuracy is damn important, though actually I basically just run.
    Sorry for the long post, and I do hope I can steal a bit of time. If you pop up in Milan happy to show you some nice city run!

  7. Mark B

    Does anyone know roughly how much training data can be stored WITHOUT a heart rate monitor? It’s 30h with, but I rarely use one.

    I ask as i’m going away and probably wont be able to sync with Polar Flow for quite some time.

  8. Paul E

    Does connecting Polar Flow to Training Peaks also allow for an estimation of TSS?

  9. Ben

    Hi there. I’m new to sports watch and have been reading up a lot and finally cut down my shortlist to fr 220 and m400 but having a tough time deciding. Where I’m staying, there isn’t much difference in the two prices.

    I want a watch that has
    1) better and faster GPS lock down n accuracy
    2) more durable (I perspire heavily)
    3) good battery life

    I’m really not into:
    1) heart rate monitoring
    2) activity tracking (wouldn’t mind having as a feature though)

    Basically I think fr 15 is suitable for me if not for the lack of bluetooth connection.

    Would you still recommend the m400 over fr 220 at this stage? Thanks

  10. Conor Garvey


    Can someone confirm that the M400 is in fact compatible with the stride sensor and if so has anyone any experience or feedback on it?

    The updates on polars site is quite confusing hence my question.


    Polar seem to have acknowledged the usb issue and will remove the rubber flap to help avoid sweat ionising the usb port this happened me twice already so fingers crossed this wont happen again.
    if this fixes the usb issue and the support for the cadence through the stride sensor is true then this is an impressive product (+ the auto link for strava)

    • Jason Oltrop

      Yes the Bluetooth stride sensor does pair with the watch and provides cadence and non-gps based pace.

      I had it enabled for the session linked below which I’ve set to public.

      link to flow.polar.com

    • Riaan

      I can confirm that the stride sensor works with he M400 for non GPS based distances, like treadmills.

      To calibrate it, you have to run outside with it first, with the GPS functionality… (or you can manually calibrate it, if you know the delta figures)

  11. Tom

    So what exactly is the “fix” they announced for the USB cover?

  12. Kinda happy polar user

    Hi Tom,

    I had to send two watches back cause of the sweat in the usb port issue where it gets ionised.

    Polar have removed the rubber flap from all new models on the market since August and will remove the flap and replace some pieces of the watch if you send the device to them when it’s under guarantee.

    I’m not saying they fixed the issue as it’s too early to draw conclusions ?

  13. Kinda happy polar user

    Hi Tom,

    I had to send two watches back cause of the sweat in the usb port issue where it gets ionised.

    Polar have removed the rubber flap from all new models on the market since August and will remove the flap and replace some pieces of the watch if you send the device to them when it’s under guarantee.

    I’m not saying they fixed the issue as it’s too early to draw conclusions ?

  14. Kinda happy polar user


    say a few requests about strave
    Flow to strava and other mainstream sports apps works well with an app called sync my tracks its not free but is worth the 2,95 IMHO!

    Im also trying a link called link to flow2strava.com which looks pretty good.

    Polar said the strava link would be up and running by the end of October but that could easily get delayed by a month or so….

    • Andreas

      I bought the app long ago but have not had it sync correctly to my Endomondo account yet.
      If anyone knows how to do this I would greatly see a Youtube manual :)

  15. Bad Red

    For me the selling point was Polar’s promise of M400 internal sensor usage for cadence, daily activity tracking with MyFitnesspall conection, and somewhere along the line notifications.
    Gues what?
    As Android user I’m dissapointed 6 month afterwards.
    First week in: firmware error and one week without running tracking. The device just froze and said: “something went wrong with your m400” till firmware update came. (Ok about 1 week afterwards new fw came, but steel…)
    After 3-4 months of use, broken strap replacement.
    Now what looks like oxidation on micro-usb connector.

    No MyFitnessPal on Android.
    No Endomondo
    No Strava
    No Cadence, if you don’t want to pay for their ugly over-sized yesteryear fotpod
    No notifications on Android
    And a TON of promises and sweet talk on their blog site.
    BTW where is Polar user forum? Nothing else to do but go commando stile bad review posting across the web :)
    Still, they have good news. Now it comes in new colors. Oh the irony.
    And, as always “hang in there, new promises on their way…”

  16. Sarel Prinsloo


    Can you replace the strap on the polar m400?

    Thank you
    Sarel Prinsloo

  17. Sarel Prinsloo


    Can you replace the strap on the polar m400?

    Thank you
    Sarel Prinsloo

  18. hermanl

    I have an allergy for nickel and would like to know what kind of metal Polar uses for the backside touching the skin/ the wrist?
    Thank you.

  19. Alex

    Yesterday, after my run I couldnt sync or charge the watch anymore. Since the beginning I always have to try several times and use the “good” cables (all my cables work perfectly with other devices but the M400 is specially “cable-selective” and needs a perfect fit/match…). I could just sync via BT right? but even then I always have to give it a few shots before it actually works… Oh I’m on Android, which for polar means months of delay for features, if they ever exist…
    Anyway, funny coincidence (well not really funny…) that I go to the website and find that the latest notification is specifically aimed at trying to keep that poorly designed USB-port alive…. link to updates.polar.com
    So according to that, after every single run you have to open the port, rinse it, and wait hours for it to dry before you can actually pull your data… Good thing they didn’t publish this during the long months were they promised android BT sync and didn’t deliver for awhile…
    I finally managed to get mine to work again after some fine and subtle toothpick engineering around the USB port… so looks like I may still have a watch to race with until I switch to a decent Garmin 920XT.

    • Ricardo

      U have to wash the usb port with warm water after every training session.. You can also use a toothpick to clean up inside the usb port… If you don’t do this most likely after few months you have issues

  20. AndiT

    SOS! Is there any way to get a replacement strap for the watch? I noticed today after my run that there’s a tear on the strap…

    • Bart

      I don’t know where you live but last year i contacted Polar directly and within a few days i had a new strap for my 8 year “old” polar for less than a few online stores offered.

    • AndiT

      Sounds great, thanks! The thing is, I’m not sure whether the strap is swappable by users, as they don’t seem to sell the straps separately.

    • Bart

      They do sell the wrist bands separately.
      One shop that i found now (and looks like the same i found last year) when looking for mine is: link to fitnessmaintenance.com.au
      I ended up contacting Polar in my country because shipping from Australia was to expensive.
      Replacing the band on a M400 is done by pushing out the metal pins all the way. (can be a little tricky)

    • Ricardo

      You have to send the watch for service at polar, costs about 27 dollars. The m400 and v800, the band has to be changed by polar

  21. Steve

    After reading your article I purchased the M400 and found it easy to use and was quite happy with it until after 3 months it stopped syncing and charging. A quick search on the internet revealed that I was not alone and quite a lot of people have experienced similar issues.

    Have you experienced anything similar and do you have any advice?

  22. I own the M400.
    Great watch.

    For running, is there a way to adjust the “training views” (or screens) so I can view ALL my splits during a run?

    I can only seem to see my last split on a screen.
    I would like to see, say my last 10 splits or something like that whilst im running.
    Anyone that knows how to do this, I would be eternally grateful.


    Follow me on strava
    link to strava.com

    Ben Fowler

  23. Stefan

    Hi Ray,
    Im considering getting a M400 as my first training watch this autumn. i have been using a box of the old CS300 and polar beat up until now for my indoor spinning sessions.

    I wonder how you feel about the readability of the screen? It seems as if the option to customise the screen offer possibilities to have quite large digits, at the cost of less information. I need to use reading glasses in order to read normally and its ok on a stationary bike, but out jogging i cant wear glasses. Radian of the iPhone screen is of course an option, but if prefer not to have to pull out the phone and unlock it while running.

    • fotis

      Hi ben fowler,

      It’s my 1st watch also for my daily activity and i have read Dc Rainmaker review throughly [ (which i dont know how to thank him for his deep analysis of the watch review) also (thanks Ray!!!! hope you are doing well for many years] before i buy it.

      Steps for training views….
      1)go to polar flow start page
      2)click your profile name top right right
      3)click sports profiles
      4)choose training profile you WANT to customize and click EDIT
      5)under tab RELATED TO DEVICE
      is Training Views
      6)CUSTOMIZE ANYTHING….!!! :)
      7)a pop up messages says please dont forget to sync your watch..
      8)sync and voilaaaaaaaa……..

      ps: I hope i helped you. (i included a picture of mine set up of running profile)
      ps2: Greetings from Greece

  24. Gadi

    I used to have Garmin 110 and I could easily see my current pace for the current KM/Mile.
    I have hard time to identify it at the Polar M400.
    Can someone advice ?

    • frankis

      Polar calls it either “automatic lap/speed pace average” which gives you the current lap pace for the current autosplit. That is, if your watch is set to automatically register a split after a fixed distance, this field will report the lap pace for that split.

      Polar also has a “Lap/Speed pace” field which is a measure of the current lap pace for a manual lap. That is, you have to manualy push the lap button to reset the field.

      Treating a manual lap different and recording it separately from an automatic lap is different than how garmin does it.

  25. Raiteens

    I am searching for my next Tracker watch and came to Polarm400 and Garmin FR220. In all cases seems that M400 beats FR220 but only thing (for me important) with what FR220 is better is vibration alert. Because I like to hear music while running (using mobile phone) but I wonder if there could be some possiblity to hear those beeps from M400 in my headphones? Some app or other connectivity possibilities?? How do you think?

  26. TR

    I’m highly interested in M400, since I’m disappointed with Garmin as my FR110 screen was misting last year fall when running and same happened again now with the warranty replaced unit. I’ve shipped them the unit back and stated that my next one won’t be Garmin probably. I still need to see what they’ll do, but probably I’ll get the refurbished FR110 again and pray what’ll happen next year, when I’m out of warranty again.

    Is there a replacement device for M400 planned by Polar ? Like some A300 features like underwater HR and vibrate option in the M4xx series ?

    In light of Garmin, who are spewing new devices with little difference every year, I generally prefer Polar style of achieving more on the software side, then just leaving their last year customers behind. So getting a M400 now, when a new device ships shortly would be a bit nerve wrecking…

  27. Rajeev Arora


    i have been using M400 for over six months now and very happy with it. one of the things that i read in the forum is that one has to stand still to get a GPS fix. that is indeed an issue

    WELL, i have found a work around for it.

    i put the watch in indoor mode. it catches the heart rate and carry my normal activities without any restrictions on movement or any specific way in which to hold my hand and so on. after 1-2 minutes, i shift to running mode and bingo, GPS is already ok.

    so, all of you who are tired of standing still while the watch gets GPS, there is hope. pl try and let me know if it works for you.

  28. PierreP

    now that android notifications are out for the V800, does anyone know if and when it will be released for the M400?

  29. Tim L

    I’ve noticed that a number of people have had an issue with a fluctuating current pace field. I had the same problems on my watch (~2 month old) and sent it back to Polar Customer Support who resolved the issue and gave the following explanation:

    “The issue was caused by a fault on the main circuit board inside the watch. This particular fault affected the distance calculation provided by the GPS sensor.”

    My experience of Polar’s customer service has been very positive – they serviced the watch within a day of receiving it and have stated that they will refund the cost of shipping.

    • fotis

      Hi Tim L,

      How can i confirm that on my watch?compare the results with another gps watch?(which i dont have) or testing with gps apps via my mobile phone application?

    • Tim L

      I initially noticed a problem because the current pace would vary by 1-2 mins/km whilst I was running at a steady pace in an areas with good GPS reception.

      Easiest way to test would be to run with a second watch, but the pace fluctuation I saw was so large that there was no way it was due to anything else.

    • fotis

      Thanxs Tim for your clarifying. I ‘ll test it with a 2nd watch borrowed from my friend.

    • Tim L

      Since the servicing I’ve been getting a whole bunch of issues with the watch – frequent GPS signal loss, and distance measured is short compared with the Forerunner 110. The distance measurement was also short prior to servicing – it measured a half marathon course at 21.0km which was unusual since 90% of other runners on Strava recorded 21.1km or longer as expected.

      I’m in touch with Polar again – will update this once I find out more.

    • That’s not that unusual. Recently I did a run with both Garmin 310xt and Polar M400 on. After 30 kilometres Polar came with 30 kilometres whereas the Garmin recorded approx 300-400 metres more.
      Last weekend I did a run which I ran a couple of times. Before I used Garmin and it came to 9.9 or 10km. With the Polar it wasn’t further than 9.55km. And during the run I got ‘strange’ automatic laps. Whereas I thought not to slow down it recorded 5’38 for a kilometer. And the signs stating the kilometres along the way were way off. Upon expecting the map the route got completely messed up. This must be caused by running a great part of it in a forest and the map shows the route not on the tracks but cutting off etcetera.

      It was the first time I got a GPS Signal lost. Just after the start in open field (although cloudy). I sometimes I get a signal lost when I pass under a bridge.

      The distance between 21.0 and 21.1 isn’t that big. Did you check the map to see if you can clarify this?

    • Tim L

      The GPS track shows a number of corners where it looks like I cut through the buildings on the side of the road. I think the issue was particularly exacerbated as this route has quite lot of corners compared to the the routes I usually run. Given the density of runners in the first half, I was probably nowhere near the shortest distances on the course, so expected the track to actually measure long.

      Polar seem to have acknowledged the issues and are now sending a replacement rather than servicing the existing watch.

  30. Rolf

    Is this watch compatible to Endomondo ?

    • Greg

      If you are an android user, you can use the “SyncMyTracks” application. It will sync automatically your activities between polarFlow and Endomondo (or other)
      (If you are on iPhone, there is a similar app but I don’t remember the name, if anyone can help).

  31. Pieter

    Export TCX / GPX from Flow and ‘import from file’ into Endomondo.

  32. Tom

    Where in the hell is the android update for notifications? Polar said September?

    • Tim L

      According the the FAQs it’s only available for the Loop 2 and V800 at the moment. M400 implementation is due “during the upcoming months”.

    • Tim L

      The latest firmware update adds smartphone notification functionality – seems to work fine with calls, texts and WhatsApp for me so far.

    • Tom

      Only for I phone. They said android would be released in September back in August. They are late

  33. lester

    New firmware is available

    Release Date: 22nd of October, 2015
    Version number: 1.7.1


    Smart Notifications for Android users, added. Requires Android 5.0 or later.
    Pause mode, distance and calorie info shown in training summary, added.
    Possible to deactivate backlight with light button, added.
    Notifications to remind user to avoid charging M400 when USB port is wet, added.
    Sound alarm for end of phase, added.
    Alarm, impossible to change AM/PM using UP/DOWN keys, fixed.
    Route starting point in equator, fixed.
    Other minor updates and bug fixes.

    • Neil

      If only I could get my M400 to connect to my PC to transfer data/update firmware. Despite trying every cable in my house (and USB port on the PC) it will only connect for charging now…. Polar should enable firmware updates via bluetooth on this model.

    • Neil,

      That is probably a cable-issue. I have different USB-cables and some only charge and some are capable of transferring data. Seems that cables might be different.

      But it could also be that the usb-port is end-of-life. I encountered that also a few months ago and had it turned in for repair.

      Do you have cables around which have worked?

  34. Anyone having NOT problems when syncing the M400 with the FlowApp on Android and having it automatically synced with the Flow WebApp?
    If I sync through BT the FlowApp gets updated but the webversion not. I still have to do this throught USB. And viceversa, because when using USB the Android FlowApp doesn’t get updated.
    This issue has also been addressed before on the Polar-forums but no reply until now.
    And I’m using the same account in both apps.

    • Tim L

      No issues here syncing from M400 to the Polar Flow app via BT, nor from the app to the web service.

    • But syncing should be automatically done between Flow app and webservice but in one way or another this isn’t working in my case. Or what am I overseeing here?
      It’s quite annoying having to sync 2 times.

    • And it seems finally, after months having this issue, solved after a good tip: removing the Android app, restarting the phone and reinstall the app. After that it seems to sync between Web App and Flow App. Hope it contiues doing so.

  35. Dejan M.

    Im very dissapointed in Polar.

    The watch wont sync via bluetooth with the flow app. It only work like once in 5 tries (and sometimes eaven then the status on the watch says syncing has failed…although it hasnt). This is a well know issue since Polar started shipping the product. Its mentioned on all of the running forums as well as on its own official forum…yet Polar has still not fixed the issue to this date. Furthermore since Android 6.0 came out the watch wont pair with my Nexus 5 at all any more (i removed it from my phone but its impossible to re-add it as it wont pair any more).

    One of the reasons i bought this device was the possibility to sync via BT (as this was one of the earliest devices where this was an option).

    Polar really should focus more on its software…as its really unfortunate for the software to be holding an otherwise really good hardware down. They should also in the future use more quality accessories in the future (my USB cable died a week after i bought the watch…and lots of people have the same problem).

    If the situation will persist im selling the watch and never buying a Polar product again.

    • Tom

      Never had that problem with my watch since March this year. I did have an issue after the latest up date with incomplete data upload after bluetooth synch. After a factory reset and removing /installing app have been trouble free

    • Jason Oltrop

      Weird thing about the Nexus 5 on Android M BT sync issue is that if location services are off it will not pair. Doesn’t appear to affect the Nexus 6 or other devices on Android M.

    • Dejan M.

      Hm…thanks… im gonna try to enable the location settings tomorrow and give it a go…although i have no idea what location has got to do with syncing via BT.

      As for the general syncing issues are concerned…i have read quite a few forums and google play reviews…and lots of users are having problems with syncing via BT (so im definately not alone in this) and it doesnt seem its a HW issue…

    • fotis

      Hi I got the same problem with you and many others as i guess.

      The solution is unpair your watch from your phone. Delete polar flow application from your phone. Pair your watch with your phone. Download again the application from google play store and sign in with your account.Then try to sync with bluetooth and everything will work just fine.The message sync failed wont appear again but instead sync completed.

      I synced in the past with bluetooth but message sync failed appeared but syncing was completed as normal.

      These things are nothing to do with serious problems….Dont get frustrated by such things….just keep running,cycling and other activities…try to perform the best you can!

      Greetings from Greece

    • fotis

      I also found out that my watch likes more the Moto G cable and its own polar included because i got strange message via my computer and believe me i have tried many time with different computers and still the same. So when i want to sync via pc the watch i just connect my phone’s cable and never have a similar problem.

      So people if you find a good cable keep it just for your watch and the polar’s cable just thow it away,put down in the drawer ,burn it lol, give it to as a gift to your friend i dont know.

      Take care of your watch and it will last many years.I am really happy with it thus it helped me to improve my fitness in many levels just for 180 euros with heart rate included.


    • fotis

      I also found out that my watch likes more the Moto G cable rather than its own but you get the point! :)

    • Jason Oltrop

      Totally agree that location services on the phone shouldn’t have an effect but with the update to Android M on the Nexus 5 my watch stopped being recognized by my phone.

      Upon enabling location services as advised by Polar Tech sup on their Facebook page, I was immediately able to sync.

  36. Tom

    Did you factory reset watch Uninstall reinstall app?

  37. Dejan M.

    I enabled the location service and now it does sync with my nexus 5 (marshmellow). It is pretty strange though…because a few days ago (since i didnt know what the problem was) i deleted the Polar watch from my bluetooth devices and tryed to re-add it (which didnt work). So now it doesn show it anymore (eaven if i click pair on the watch Nexus doesnt list it under bluetooth settings). Since it wont pair the “regular” way its strange that syncing works via the app anyway (if location is included ofc). It would be morel logical that it wouldnt since i manualy deleted the device and i cant re-add it under BT settings…but hey…im just happy that it works ;)

    Tom: i haven tryed that yet…for now ill keep using the location…and if that stops working ill try your advice as well.

    Thanks for the tips guys.

  38. Arturs

    Hello! Maybe someone can give me advise regarding Polar M400. I was considering this device with Hear Rate monitor bundle or Fitbit Charge HR as Christmas present for my girlfriend. She mainly do walking, so I was considering are there any advantages of GPS in walking mode ? For example, can you see later in the app your walked path on map, distance, etc ? Currently, I am leaning more towards M400, because I’ve seen many complaints with Charge about skin rash issue and not so precise optical heart rate sensor.

  39. Dejan M.

    Arturs: check DCRs review of the FitBit charge…while the optical sensor is not good (accurate) enough for more serius exercies ie running etc…it should suffice for the walking purposes and for beginners (runners).

    If a watch has a GPS you can (after syncing) see the distance you made on a map (consequently also pace etc).

    Fitbit also has a nother model called Surge which also has a GPS. Dunno about the skin issues though…i never owned any of their products.

    Since she is only going to use it for walking and her being a girl it comes down to two things: Chest strap vs Optical sensor and looks of the device. I doubt she will like putting the chest strap on every time…

    • Arturs

      Thanks for reply. It is really hard to decide, what device could be the best for her. I liked the M400 judging by review, but after some more thinking, it could be too bulky for her. On other hand, Fitbit Charge HR and also Surge could be ruled out, because of common cases of allergic reaction. Maybe I have to look for devices from other manufactures like Garmin in a budget of 200 EUR.

  40. jp

    I just bought a polar m400 watch however when i go onto the sportsmode on watch i am missing activities such as swimming etc. when i go onto the website after logging in there is no option to add sports activities as its dull and nothing else displayed. Any solutions please!!!!!!

  41. Lars


    First of all a big Shout out to Ray for his extensive work here.

    I’m looking for a new watch, I dont’t need all the powermeeters and such. I just need one like the M400, a happy non elitist 5 times a week running biking peron. Heartrate and intervals is the most important for me. The M400 seems to tick all the right boxes, apart from this.

    Am I correct in assuming in order to create intervals, and change layouts on my different screens (for different actvities) I need to go to the websync and physically hook up watch to PC/Mac. I can’t create it on the web, and then sync the changes/layouts via the flow app?

    This is what I do when on the road (which I am a lot), often without access to PC/Mac for weeks, but have phone/tablet with me.
    I log into Garmin Connect on web (but in my phone’s/tablet’s browser). Create an interval, Close my phone’s/tablets webrowser. Open Connect App, find the newly created intervals (the one I created a minute ago on the phones browser, synch to my Gramin product via BT. No Cables, no PC./Mac Just Garmin product and phone..

    Can anyone tell me if Polar have realized that we don’t need PC/Mac anymore??


    • Jens

      I can only tell from the v800 but the systems should be similar. You can create a workout in flow (the website) and it will get syncronized through the Android App to the watch. You don’t need to sync the watch via USB.

  42. Paulos

    Major Fail. Why would a product that touts direct syncing with Android phones and tablets require a Microsoft Windows computer in order to add the device to the Polar Flow account? So I need to buy a laptop to get my Polar phone to initially work? Why can’t I simply enter my device model and serial number into the website?

  43. Paulos

    Why would Polar require users to have a Windows computer for initial setup of this watch, especially when Polar touts this watch as a device that can communicate directly with an Android phone or tablet–bypassing the need for having a laptop?

    I called customer service. The representative was snide and insisted that I should have known a laptop was required.

    • Heath

      As of now, polar watches are unable to update its firmware from handheld devices. The only way to keep them updated requires Polar flowsync. To make things even completed, the mobile app sync its backend data with the server. This is a potential problem when there’s a firmware update for the watch as you won’t be able to sync your workout to PolarFlow. One one or another, you need at least a laptop for it or you could ask for a refund if they allows it.

    • Lars

      Well to be honest, I got the part with the windows and all..
      But I would love a product where I don’t the have to borrow a PC / Mac (yes I actually don’t have a PC/Mac, I do all on tablet and phone) in order to get my future watch to work. I can for the life of me not understand why it cannot be done on phone/tablet. And then synch via BT.

    • Heath

      As of now, polar watches are unable to update its firmware from handheld devices. The only way to keep them updated requires Polar flowsync. To make things even complicated, the mobile app sync its backend data with the server. This is a potential problem when there’s a firmware update for the watch as you won’t be able to sync your workout to PolarFlow. One one or another, you need at least a laptop for it or you could ask for a refund if they allows it.

    • And to be fair, that’s the case with many Garmin watches as well (requiring either desktop or WiFi for updates).

  44. Lars

    No problems… I don’t have a Polar (it was Paulos who bought one) I were just enquiring on some questions earlier (making intervals on the go/no need for laptop for the m400). My latest comment were actually just a wish. I’m not a supertech kind of guy, but I’m still baffled why we can’t make updates and all that, only with phones /tablet in this day and age. There might be some technical circumstances I’m totally oblivious to (probably). But I can still do all my banking, payments, shopping, work, entertainment without computer, so that’s why I wonder…

    What about the new TomTom…. Do they also need a regular hookup with computers? What about suunto? Is there any watches that can update and customize only by phone/tablet?

  45. Q!

    Does anyone know when will the new “m400 version” come out? Should I wait to get a newer version?

  46. James

    Note to regular Polar M400+Flow users… Polar have sent out a survey to some folks giving us a direct opportunity to influence product development. I’ve taken the time to respond in the hope it will!

    For what it’s worth this was my feedback to the “what essential(!?!?) features is either M400, app or Flow missing”:

    1) Ability to override Max HR and Max Speed in Flow (Max HR in particular is an important metric to track accurately – if I forget to wet my HR strap I get ridiculous readings I can’t correct and the “best session” area in progress section on Flow is meaningless)
    2) Ability to name individual training sessions to be able to see at a glance in diary view e.g. “Intervals 5x5mins”, “Long slow distance”.
    3) Ability to combine sports in progress reports (e.g. Running+Treadmill running, Cycling+Indoor Cycling, Swimming+Open Water Swimming etc)
    4) Use internal accelerometer to avoid footpod requirement (pain when using multiple shoes)
    5) Allow bluetooth speed/cadence sensor integration (cycling)
    6) Allow open water swimming smoothing in Flow
    7) Addition of vibration feedback to watch
    8) Fix Android smart notification (The background flow service either gets stopped by Android or crashes and doesn’t restart on Galaxy S5 – not sure which but this unreliability makes it useless)
    9) Add simple stopwatch that doesn’t record a session (e.g. kids want timing running round a track etc).

    • jonlynch

      Nice list James, I didnt get a survey from flow but have sent mails to the polar product team previously, none which I got any response from.

      I had similar issues with some of the items you have listed too.
      1) with bad HR readings, so I downloaded the tcx file, deleted it from polar flow, modifed the tcx manually to remove the invalid HR readings thinking I could upload the tcx file but no, but you cant upload a file to polar flow. Only sync from the watch. So I lost this session which would contribute to my running index.
      5) the FR230/235 now supports cycling speed/cadence sensors. I stopped using the m400 for cycling over it not having cadence support and went out and bought a garmin edge for cycling. Im not wearing a dual B+/ANT+ HR strap during my commute so my polar daily activity stats are not very useful seeing they are missing this cycling activity.
      8) With android smart notifications I end up restarting my phone if Im not getting notifications. (maybe force stopping the polar flow application and restarting would work too, but I preferred the restart option)

      Additional things I would like with smart notifications
      a) in dark when a notification comes and im cycling, I cant easily turn on the screen light to actually glance at the notification so it would be useful if there was an option to automatically turn the backlight on when an notification arrives for a few seconds
      b) a small history of notifications (e.g. the last 5) which I can browse, the notifications disappear off the polar m400 screen after some length of time and I may not have had the chance to read them. It would be great if there was an option when I press up/down buttons for notifications so I could browse these.

      * Does anyone know if the polar flow app “consume” the notifications for certain applications, ie, if I get a whatsapp message, the notification is delivered to the m400 but disappears from android 5 drop down notification area, whereas for other applications the notification is delivered to the m400 and remains in the android notification area.

      * I couldnt find the character count previewed by the m400 of the notification in the documentation/release notes. But it seems to be 35.

    • James

      Hi jonlynch,

      Good to see you have similar experiences and have provided feedback to Polar so we hopefully get an even better product! I also use Garmin Edge for cycling (but wish I didn’t have to bother).

      I like your other suggestions around notifications. I guess I don’t have much experience of these due to the unreliability I’m experiencing and it now seems to have auto-disabled itself and I’ve kind of given up on them. How often do you find you have to restart phone/app to keep M400 notifications working? (I seemed to have to do it every few hours!).



    • jonlynch

      with the latest update of polar flow 2.5.0 on the 4th of Nov, it has improved, my phones uptime is 36 hours (no manual app restarts) and notifications have been sent to my m400 for all this duration. My phone is Moto E (2nd Gen) with 4G with Android 5.0.2

    • James

      Ah interesting! That 2.5.0 4th Nov release was badged as A360 support but I’ve just dug into the release notes and it says “Smart notifications cause Flow app to crash in some cases, fixed”. I had another go re-enabling smart notifications last night and although early days at least it was still working this morning. I will keep my fingers crossed this is now a lot more robust! Thanks for sharing.

  47. Andrew

    After reading and re-reading this brilliant review (thanks Ray for all your fantastic, in-depth work on here), I finally bought this back in August.

    I went in expecting a few quirks based on what Ray and others have said, but for the price point, and as my first GPS watch, I thought it was worth taking the plunge. But I have to say I’m a bit disappointed with my M400:

    1) The battery life is not close to what is advertised. I wear it most days as an activity tracker, but am getting about 4 hours of battery life when GPS is used (I run and cycle). As it stands, it won’t last long enough for me in a marathon (something I’m looking to train for over the next 12 months).

    2) The GPS lock is not great. At first, I was amazed by how fast it was finding GPS (even finding it when I was indoors), but now it takes several minutes. I don’t live in a built-up area, but even standing still, with the watch facing upwards, it’ll take 2-3 minutes to find signal, often going up to 90% before dropping to 40% or less.

    3) Like many others, I’m incredibly frustrated not just by the lack of Strava integration, but the repeated delays in delivering something that is standard on other competing devices, and in Ray’s own words, is not difficult to deliver.

    I’m going to reset my device today and see if that helps with 1) and 2) – hopefully I’ll see an improvement.

    • Tom

      You have a faulty watch. Battery life is no problem. I am a slow 4:20 minute marathon guy and had plenty of battery left over. Replace it under warranty.

  48. Pieter

    Just my personal observations, which might of course differ from yours:

    1) Battery life: Have done many events > 4h, longest 7h and I still had 10%+ left at the end of my 63 km run;
    2) GPS lock on – quick and stable, even beneath cover (latest firmware);
    3) Strava integration – not such an issue for me, I export the TCX file and import into Strava and voilà! Yes it does take 3 or 4 clicks exactly, but really not such a pain for me.

    Kind regards

    Pieter .

    • Andrew

      I do wonder whether I might have a hardware problem. Been running the latest firmware (1.7.1) and have been syncing via USB (which refreshes the A-GPS) but it’s been a real irritation for me. Which is a shame, because I really like the watch and it had been great for the first couple of months.

  49. Niek

    An easy way to transport your activities to Strava is http://www.flow2strava.com

  50. Amil

    Hi All,

    I also bought the m400 in August thanks to the splendid DC review (thanks again Ray) I never had any issue at all since yesterday: all of sudden fixing took minutes (instead of the usual 30 secs) in the first 5 km of the run lost GPS about 30 times and then, in the last 4km, I did not get any gps signal at all! I wrote to polar in my country and they suggested factory reset; I did it, and today no fixing problem but at 8 km, again GPS signal totally lost and not recovered in a huge boulevard without tall buildings around or trees. now seems polar is saying that fro GPS issue new sync would solve the problem with A-GPS; however I doubt that my huge problem is due to that, probably hardware issue? any thought? thanks!

    • Tim L

      There are problems with the latest firmware update – I’ve been getting extremely bad GPS issues recently with constant loss of GPS signal.

      Polar have confirmed that there have been problems with the A-GPS:

      “The M400 has an GPS issue at the moment, I’m afraid. A-GPS data isn’t updated to device after firmware update. However the fix should come out tomorrow [10-Nov-2015]. It doesn’t require M400 update but is made in the background services. ”

      I’m on my second M400 now, and have had issues with GPS accuracy on both watches. Polar support have generally been responsive, but the watch has been so unreliable that I’ve been doing all my runs with an FR220 as backup in case the M400 screws up the data, which it has done frequently.

  51. joli

    The fix is now available. Please sync M400 with FlowSync to get the A-GPS data updated.

  52. Martin

    I’m about to buy the M400 but I’m not sure if I can use the Scosche+ and the Polar Bluetooth Smart footpod at the same time?

  53. Alex

    Here’s my feedback after 1 year of ownership:

    Generally pretty happy with the watch for basic running. I usually leave it near the window while I get dressed so it has a GPS fix by the time I’m ready to go (+ I sync several times a week after each activity so A-GPS is often up-to-date too).

    GPS trace is good enough most of the time, but altitude is always out of whack at the beginning, and settles in after a while…

    I’ve had a few crashes during runs/rides, maybe 3 or 4 max in a year, so not that bad, fortunately not during important events, and mostly during previously loaded workouts (but not only).

    Not very pleased with Polar’s ability to keep up with their update “promises”, to say the least… actually I hate them for it! Be it MFP integration, phone notifications, strava integration etc… never seem to make it on time…
    And when they finally get their shit together and actually deliver something, it’s often for iOS first, and us Android users have to wait another (few) months… By that time, I’ve usually gave up the idea of actually using the watch for anything else than the most basic functions…
    The “Oh sorry LOL!!! maybe next month! Finger’s crossed!” attitude only makes it worst…

    Anyways… the watch died a few weeks ago… couldn’t charge or sync, even after cleaning the connector with toothpick etc… so I sent it back to Polar. They fixed it pretty quick and sent it back after replacing the USB connector on the back (the one without the cover)… but now it also has scratches all over the back (also they ripped up the original box and the front had greasy finger marks all over… not that big a deal but shows how much they care…). Hey at least it works, not sure for how long but I can run without my phone again.

    So, over the course of the year and about 250 sessions (run, bike, OW swim, tri…), and a kind of love/hate relationship with the watch/company, still not that bad of a deal for 160€ at the time.

    Now waiting for Santa to bring me a Tri watch / 920XT for next season.

    Sorry for the wall of text / rant, just my experience… :p

  54. Mike O

    Hi Guys,
    Just wanting to follow these comments and this is faster than scrolling down on a mobile!

  55. Tim L

    Does anyone have an issue with inflated average pace data when GPS signal is lost during a run, and then the run is uploaded from Flow to Strava (via the .tcx files)?

    Typical situation:

    1) Watch loses GPS signal during run and the M400 doesn’t record any data during this period
    2) Strava doesn’t include this no GPS period in the moving time calculation, but does include the distance travelled, thus decreasing average pace,

    This doesn’t seem to occur with any of the Garmin watches I’ve used as they don’t seem to lose GPS as easily, whereas with the M400, at the slightest sign of difficulty I will immediately receive the no GPS message.

  56. Johnny

    Curious, never saw this mentioned. With the watch, if you’re doing interval or phase training, can the polar m400 give you audio cues over bluetooth earbuds similar to runkeeper app? I’m hoping with interval trainig, it will cue when to rest, resume, etc. Hope this question makes sense

  57. Steve

    While using the bluetooth HRM (H7) with the watch, can I connect the HRM with Strava at the same time?

  58. Dénes Szluha

    I just realized that training load and recovery time is now indicated on the Polar Flow app (iOS version). It suggest me that we can expect upgrades on the Flow web..

  59. JL

    Has anyone had the rubber around the watch start to peel? I bought the watch back in January 2015 and it started happening about a week ago.

    • Stevie

      Bought my in Nov 2014 – have used it pretty much everyday (run or cycle to work) – have not looked after it any special way – sometimes it comes into the shower with me, sometimes not. Not done much swimming at all, but like I said very impressed with in the ocean last week. No rubber peeling and very little dis-colourisation (I got the white version). I am sure if I had a brand new white one to compare mine would look a little tarnished but it does not look bad at all.
      Still really happy with it.

    • sportgebbi

      Using mine since October 2014 basically every day 24h and got since three months the same problem. Is getting worse and will send it to Polar for replacement of strap.

  60. NorCalGal

    Distance runner, female, 5’10”, competitive (sometimes).
    Have owned the Polar M400 for almost a year. Here are my impressions:
    The Good:
    -4 data fields per screen
    -easy to read display
    -band is comfortable & fits well, even on a small wrist (5.75″)
    -universal usb/mini usb connection is convenient compared to proprietary connections
    -no problems with mini-usb on watch (I am careful to wipe it off before/after each use)
    -GPS seems reasonably accurate & locks on quickly
    -on-screen review of workouts from past week is great — pace, distance, etc.
    -multiple sport profiles w/customizable metrics for each is handy
    -interval timer can be set w/2 different times/distances — very handy for workouts
    The Not-So-Good
    -the soft material of the band makes it difficult to pull a sleeve over it — found this more irritating during the colder months when I’m pulling tops on/off
    -relatively short battery life (8 hrs in GPS) compared to other watches
    -the alarm (interval timer) isn’t very loud, as others mentioned. I have excellent hearing & if my armswing is behind me, I don’t hear the “beep”
    -Polar Flow for iPhone looks pretty, but the bluetooth upload has worked maybe 1/30 times I’ve tried it. Not exaggerating. Finally gave up & plug in to USB to upload.
    -No push to Strava
    -can’t turn off activity tracking (which I don’t care about)

    What finally killed it for me is the unsuitability of the Polar Flow website for a competitive runner who wants to plan/review training. You can’t look at a month (or a week’s) runs on one screen to see total miles run.

    Polar Flow shows activity time elapsed and calories (which I don’t care about) rather than useful info like miles run, miles walked, etc. The “reports” is currently not working, and again doesn’t provide useful info for a competitive runner such as the ability to see miles run vs. miles/time spent in other activities.

    The only way to see miles run in each training bout is to click on the activity & wait for the screen to reload. Every. Time. Cumbersome & slow. Finally exasperated. Just bought a Garmin Forerunner 230 online & can’t wait until it gets here. I’ve owned 3 Forerunners & switched to Polar after the screen fogging/reliability issues w/Garmin got me to try Polar. Going back to Garmin, fingers crossed.

    DCR, thanks for all your great reviews over the years. Yours is the first site I refer people to when they ask re: gear info.

    Cheers & happy holidays.

  61. Brian M

    I’ve noticed the 2 times that I’ve been cycling with my watch mounted to my handlebars and I’ve also gone out of bluetooth range to use the bathroom when I come back in range the watch doesn’t reconnect to my heart rate. It is kind of disappointing when you don’t have HR results for the 2nd half your ride.

    Does anyone else have issues reconnecting your heart rate to the M400 after going out of bluetooth range? Do dedicated cycling computers have this same issue? I know that iPhones don’t have the issue. Thanks.

    • Eric

      @Bryan, if this happens again, press long on the light button and scroll down to “search sensor”. It will reconnect straight away.

    • Brian M

      Thanks Eric. I will try that next time. Sadly Polar support didn’t suggest that method to reconnect. Im looking forward to trying that out.

  62. Kaue Pepe

    Finally! Strava Integration!

  63. John P

    I recently had a Polar 400 for 28 days but returned it to the vendor due to its barely audible sound levels. This is really too bad as I appreciated many other excellent features, particularly the ability to select information to be displayed in training views. This enabled me to display one or two parameter at a time in larger font and thus not need to wear glasses while exercising. There is no vibrate mode and not wanting to look at the display to see when I pass a kilometer point or stay from a heart rate zone, I need reasonable sound levels which in the unit that I tried were quite pathetic (all sport profiles had sound set to “very loud”). The alarm also emitted a muted sound that would not wake anybody. I have excellent hear and can easily hear sound from Garmins and other devices warn by running companions.
    I have suggested to Polar that they publish decibel sound levels for the various sound level settings

  64. David Goh

    Why doesn’t Polar support uploading of training files into Polar Flow?

  65. Hugo


    Thanks for the fine review. I bought recently the M400 and i am very happy with the watch, but it misses two functions that i consider that would take this watch one step ahead and make happier a lot of m400 owners. Virtual racer and virtual pace are the two functions that i mentioned. For alone runners, like me sometimes, i think that is nothing more motivation than running against our own, and see the distance i am in ahead or behind. Do you now if polar team is considering include this options in further updates? what is the main channel to reach polar team in order do request this options.

    Thank very much

  66. Kurt Owens

    I have had the watch for 2 days and it is driving me nuts. I seem to constantly hit that center button when I move my wrist throughout the day next thing you know I have hit the button to get to the run screen then hit it again to start a run. I have started about 6 runs just doing stuff around the house. I can’t help but feel this watch is unusable as an activity tracker. I have moved it from my left hand to my right hand this morning but it just feels so weird on that hand there is very small chance that I will keep this watch.

    Am I the only one that has this problem?

    • Greg

      You can choose to lock automatically the buttons to avoid these issues. You’ll have then to press the upper left button for a while to unlock it.

      From the manual :
      “Choose Manual lock or Automatic lock. In Manual lock you can lock the buttons by manually from the
      Quick menu. In Automatic Lock the button lock automatically goes on after 60 seconds.”

      Hope this helps.

    • Jan

      I’m guessing you are… since neither me or my wive have experienced this during 1 year of daily use! The most simple solution is just to lock the buttons (push long on top left button to lock and repeat to unlock). Fact is I need to do this while mountain biking since otherwise indeed it activates the buttons with wrist movement of gloved hands…

    • Kurt Owens

      You guys rule. I was wanting to keep this watch as the price I paid was ridiculous. REI had it in the returns section where it was labeled “won’t sync with phone and chest strap. Untested…..Possible user error” and most importantly “$29.83″…..I took it home restored software and it was good to go but it had no instructions.

      Went there to buy the Garmin FR230 or 235 so to walk away with comparable product at $30 was a no brainer.

      Looking up how to lock again I appreciate the help

    • dojo

      You can find user manual online or you can download it as pdf

      link to polar.com

      There is no manual in the m400 box. Just some short guide.

    • Tom

      I would say you are one if few. Work great for me. Every once in awhile it does that to me. Had watch for 9 months now

  67. Wesley Forbes II

    Hello and Happy New Year to everyone! I have had my M400 since it came out. After waiting for them to finally get Android notifications to the M400, I am having a problem. Every type of notification comes through to the device, except for incoming phone calls. Instead, after the call is missed, then it will notify me of the missed call with the option to call back. I am sure that I have something messed up. Any suggestions?

  68. Jean-François

    Hi guys,

    I’m looking for a gps watch for mountain biking and cross country skiing and the Polar M400 looks like a winner for me (it’s cheap and does what I need)

    I don’t need any power, ANT, Heart Rate stuff, training etc. Just the basic recording of distance to put that on the map in the web app at home; the recording of elevation would be a plus.

    My only concern is the ability to custom the display. All I want on my first page is the distance, the elapsed time and the actual time (clock).

    Can I put those 3 informations on the main screen and will it be easily readable while biking or cross country skiing, i.e. would the numbers be big enough for an easy read.

    Considering my usage (for mountain biking and cross country skiing) would there be another watch better suited ?

    Thanks for your time guys.

    • Tom

      Yes you can have several screens showing different things all set up by you. Each screen can show 1 or 4 inputs up to you.

    • Jean-François

      Thanks Tom.

    • cuh7b5

      I think you cannot go wrong with the M400, this is the best-buy GPS watch available today IMO. Maybe you will use only a small subset of all its features but I cannot mention a cheaper and less featureful model. And yes, you can customise the training views. You can place up to 4 items (including the ones you need) on each view and as many views per sports as you like. If you place only two metrics on one view then they show up quite big. If you place more, the letters will be half the size but still quite readable in my opinion. You can see the elevation as well but I am not concerned about its accuracy as I do not use it. Elevation is measured by GPS which is known to be less accurate than metrics based on baromatric pressure. But hey, why don’t you read the review and posts above? ;)

  69. Mark Hughes

    Has anyone managed to get an updated A-GPS download from Polar Flow sync this year? I’ve synced my watch about 10 times and it steadfastly seems to stick with an A-GPS expiry date of 11/01/2016. Looks like maybe Polar haven’t updated the source since the new year?

    Can a few people check and see if they’re seeing the same expiry date? (Settings -> General -> About Your Product -> one of the screens has the A-GPS expiry date on it).

  70. firsthuman

    Running cadence is available.

    link to updates.polar.com

    Is it accurate?

    • Neil

      Thanks for the heads-up firsthuman. I’ll update later and give it a go.

    • Mike J

      I just updated for the cadence functions and added it to some of my activity profiles, no idea yet if or how accurate it is functionally since it is below 10degF outside and I don’t feel like going outside right now.

    • Neil

      It’s 40C/104F here, so we have similar (but opposing) problems :)

  71. AndiT

    What happened to the cadence update? Did it get pulled? The link from Ray’s twitter feed is not working anymore, and it’s now not listed amongst the updates on Polar’s site.

    I downloaded the update yesterday.

    • It was pulled, sounds like folks were having bricking issues.

    • AndiT

      Great… Thanks for the info!

    • Mike J

      Uh oh, that doesn’t sound good. Now I’m wondering if they will provide an uninstall update since I already updated and configured cadence into some training views, but haven’t used them yet. To be safe I think I’ll go back and remove the cadence from my training views, don’t want to wear a brick on my wrist.

    • Riaan

      I updated the FW yesterday, and had no issue re bricking, etc.
      I never changed any view settings, as my unit were set to use the Polar “Chicken Egg” Footpod, for cadence/steps in the views.
      In previous cases where I ran without the “egg”, it never showed any cadence.
      Today, without the footpod egg, and using the built-in accellerometer , it did show me my cadence/steps.
      I didn’t have the Garmin “Dove Egg” on the other foot, so I cannot compare the accuracy.
      However, looking at the same run(route) done previously on numerous occasions, and my normal cadence, it seems to be spot on.

    • Pieter Oosthuizen

      I sync yesterday afternoon with the cadence release, and also created a cadence view.

      Went out for a run this afternoon – the cadence view didn’t show (I am quite sure I did sync afterwards, but the I do remember the connection was very unstable, losing the M400 regularly.)

      However – I do see the cadence now on Flow:

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



    • Pieter Oosthuizen

      Note the difference in reporting of the SPM between Flow & Strava

    • Mark Hughes

      Unluckily I managed to get the update for cadence – I thought I was in the clear as the update worked fine but now every time I try to start a running activity, it immediately crashes with the “Something went wrong, press OK to restart the M400” message :(

      I’m going to try a factory reset tonight using flowsync and see if that clears it up, else it’s properly broken.

    • Mike J

      Please let us know if it works out for you.

    • Mark H.

      The factory reset didn’t help, but removing the new training view I’d added with cadence/stride length and syncing that did. I was then able to re-add the screen with exactly the same details I’d had before, and now it seems to work fine.

      I haven’t been for a run with it since fixing it, but bashing the watch about with it on running mode shows some cadencey type figures coming up so I assume it’s all working now. I’ll report back on Monday whether it continues to work while running, but for now I think we can assume this was something to do with the process of adding the new screen rather than the firmware update per sé.

  72. Panos

    Running cadence via internal accelerometer with the last update works perfect!

  73. 1LightningFan

    I downloaded the update with the cadence feature on my M400. I also update my training views on my watch to include the cadence results. I used it in a run last night with absolutely no issues. I synced my run via the IOS app – again no issues. Everything seems to be working fine. From my experience I don’t understand why the cadence update was pulled.

  74. Robert B.

    My M400 is working sweet, It did take 4 times longer than normal to update, something like 20 minutes when its normally far less than the quoted 10 minutes. I see the V800 is also affected so I best go for a run with that tomorrow.

    • Neil Aldridge

      Cadence is working for me now too.
      After going through the training view setup for running (which automatically had a new screen of ave cadence/ave stride length), I had expected that stride length was also being calculated/displayed (like my wife’s Garmin VA) but I got zero values on my latest run.
      So it needs a footpod (unlike the VA)?

    • Same here. After the FW-upgrade I made a screen with current en avg cadence-pace and also stride length. Finally I got to run again, after 2 weeks of backproblems. Stride length was continously 0. Cadence-pace gave quite the same values as I had before with the Garmin and a footpod. But it only calculates half of the steps per minute. But I can live with that. ;-)

    • One thing I forgot to mention was that under a clear blue sky with Sunny weather after approx. 600 metres my GPS signal was lost. Had to finish the workout and start another after getting GPS signal again. Never encountered that before, except when passing under a bridge. A-GPS-data was recent (end-date Jan 26th).

    • Pieter Oosthuizen

      Confirming the above observations. (Zero length showing, and only ‘half’ the cadence :) )

      But a cool feature nevertheless, which I find very useful. Thanks to Polar for keeping on bringing new functions to the M400!

    • cuh7b5

      I agree! Cadence is a very welcome feature even if it came far from being fully tested. :) Same here: 0 stride length, 0.5*cadence, but seems to be quite accurate. I am happy that I could update before it was revoked, who knows when it will be fixed and offered again…

      The update took a while but went fine. I do not have any GPS issues either, the expiry entry is up-to-date as well.

  75. Pete Beatty

    I was using my M400 with a Wahoo Tickr Run and on uploading to Polar Flow it was showing cadence information and graph.
    I am wondering if this is going to be accurate?

  76. Ellen Marie Ariansen

    Rey (or anybody who can answer), how does this watch compare to the forerunner 230? The m400 is nearly half the price of the forerunner. Thanks :)

    • runnershigh

      First of all; both are good deals. The FR230 is not that cheap but much better battery lifetime (16h instead of 7/8h), a colored display, a may be better GPS (which is only an advantage if you have slightly bad gps-conditions). The FR230 is slightly easier to wear (less size/weight).
      If you basicly use HR-based training than the m400 would my suggestion/favorite.
      If not, than I would prefer FR230.

    • Ellen Marie Ariansen

      Okay. Well i do orienteering, so a good gps is one of the more important functions. At the same time pretty much all of my training is based using my HR. I have the same impression of the watches though, that the m400 is better on puls, but that 230 could have a better gps. But in the end I suppose the fr230 is a better watch, but that the m400 is cheap for all the functions it has.

  77. Mark H.

    The cadence update is back for anyone who didn’t get it the other day (sounds like it was just the V800 one that was having issues).

    After sorting out my screens, I’ve had no problem with the update – it seems to give reasonable data, although I have absolutely nothing to compare it to :) I seem to average 78 steps per minute, very consistently.

    • feelthhis

      Thanks a lot for the updated.

      Unfortunately they took too long to release the update and I already got the TomTom Runner, which supports cadence but not in real time (just for show in the post run stats).

  78. Jeffery Rehner

    I’m having an issue with my m400 and wahoo tickr Run. If I use the tickr Run the m400 will not register distance or pace (both 0) but will register hear rate. If I do not use the tickr Run then the m400 will show distance and pace. I have tried repairing with no success. Any suggestions?

  79. Lana Allen

    Hi. I have read the GPS battery time is only about 5 hours. Is that still the case or by January 2016 has that been improved?

    • Pieter Oosthuizen

      I have done ~5:45 ultra and there were still some battery left. (WITH HRM etc) (Jan 2015 model)

      (Also completed an ~7h event but without HRM)

      The ‘issue’ is that you can’t start a new recording when battery is on 10%, but if your activity takes it below 10% it will still be recording.

      My GUESS is that you will be able to get 6,5h with 7,5h – 8h possible perhaps (?)

  80. Dan Hannigan

    DC, I am considering using this for tracking my progress specifically for bicycling, I ride based on a program that a close friend of mine has designed for me, he has recommended this unit for tracking my progress and making sure that I am in the proper zone on my daily rides. He is both an runner and a cyclist and had me review the entire review you had written and I am just concerned that this will allow me to be able to track and accomplish my goals for tracking my cycling, what are your thoughts on this for purely a cycling watch and tracking my heart zone workouts

  81. Jasper

    I’ve encountered the following problem: I’ve prepared some interval training sessions and stored them as favorites; warm-up, work-rest (x times), cooling-down. Pretty straight forward. All starts well, but the problem is in the cooling-down bit. The watch doesn’t log what I have entered as cooling-down distance or time, but takes the last ‘work’ distance or time and uses that as my cooling-down part. How weird is that. I’ve double checked what I have entered as my training, and that is correct.
    For example: I just ran 2.5 km warm-up, 10 x (2min work, 1min rest), 2.5km cooling-down. After the last work-rest session (and I assure you, I can count) the M400 tells me to ‘work’ for 2 minutes, instead of 2.5 km cooling down.
    I gets even more weird: when downloading the info to flow on my computer (did I already mention, the M400 doesn’t sync via Bluetooth to my iPhone 6?) the last phase is shown as ‘cooling-down’ (while the watch told me to ‘work’), but with the duration 2 minutes, instead of a distance of 2.5km.

    Am I totally missing something, or is something really wrong with my M400?

    Apologies for this long story, I hope it makes sense.

    Kind regards

    • Martin

      Hi Jasper,
      exactly the same problem here. Instead of cool-down, I get yet another ‘unscheduled’ repeat of the previous step (work). After syncing, Flow shows the activity structure as expected, even though there seems to be a weird/extra division line before the cool-down step. I haven’t found any solution yet.
      Any insights, anyone?

    • Nikos

      Exact the same problem. Non scheduled activation of training steps.
      The watch totally misses the training program. Wrong set count, wrong phase announcement, triggers rest step without activation e.t.c. Totally misses and breaks my work out.

      I have contacted with polar since January 22, and they told me it is the latest firmware update. They found errors and they are trying to fix it asap.

      I asked them to give me information for reverting to older firmware, cause my watch is useless, and they keep saying they trying to do their best to fix the problem, after 1 month of issue……

      I am happy that i have my Fenix 3 loaded with my work out training programs.

    • Jasper

      I’ve contacted Polar support in the Netherlands; they have forwarded my query to Finland development department. No reaction to date….

    • Nikos K.

      I did a follow-up with polar Finland and same answer.

      “We are waiting for software fixed”.

      It is so shame they didn’t fixed a firmware problem since 20 January release.

      The watch is unreliable, as for Custom Work-Out Training. It is also not comunicating any more for notifications.

      Very disappointed of polars error fixed responds.

      Their Latest Answer :


      There is no new update for M400 available but the latest version is 1.8.4 which yu have updated earlier.

      However, unfortunately we’ve noticed an error there and are looking into it. Hope to have it fixed asap. Thanks for your patience.

      Best Regards,
      Global Customer Care/ Anna-Leena
      Polar Electro Oy

  82. Fredric Luthman

    In order to get training load and recovery from the M400, what do I need? I’ve got a Schosche Rhytm+ and I prefer not to use a chest strap, but I will if I have to.

    Buying the polar HRM bundle costs about 25 euro more here, so I might just buy that.

    Do you need to enable all sport profiles beforehand on Polar Flow before using them on the watch? (Like Cross Country Skiing, Badminton etc etc).

  83. Teo

    hi!! what do you think is the better product, value for money the fr 620, fr 230 or the polar m400? thanks a lot

  84. stefano

    Hi there just some news to be updated: polar added cadence and recover time ( this only in polar flow web site).

  85. Hi. I purchased one of these a while ago based on your reviews and suggestions regarding all of these watches etc. and I’ve been very happy with it.

    I have a question though; if my main sport is ice-skating and I want my sessions tracked in as much detail as possible, what kind of watch or extra sensors would I need to look at getting? Ideally I’d like to know how fast I’m going and the distances that I’m travelling, and being able to work with laps etc. would be great as well.

    Thanks in advance, Charles.

  86. Bill K

    My name’s Bill. I’m a Masters Bike racer.

  87. Christian Köhler

    I have mine since may/2015. I am not impressed with the durability of the watch. Plastic on the backside under the watch got weaker over time and has finally broken. A piece of plastic that holds the cover for the USB port got lost (including the cover) and the plastic under the buttons is loose and can be pulled away with a finger. The wrist band also looks very worn out. There is a large gap between the band and the watch where the rubber comes of. The USB data connection is unreliable (many users reported that problem). While the watch is functional and water proofing is still intact, It doesn’t look acceptable as a day to day watch anymore.

    I have used the watch as a dayly watch, for running (6 hours/week) and casual cycling. No “contact” sports etc. Disappointing.
    I am using my old RCX5 again. The build quality was mutch better (metal case). It was in use for nearly 4 years and it is in much better condition. Scratches aside, everything is fine with that one.

    I like the functionality of the M400. Are the Garmin watches more durable? Maybe the V800?

    • Robert Black

      Hi Christian, did you know during the production run Polar did away with that plastic cover on the M400? I wouldn’t worry about that. On my V800 they went the opposite way and added a charge port cover.
      However I fully agree that my m400 looks decidedly tatty too for being 10 months old. better materials next time please Mr Polar!

      I will say that I’ve never had a sync issue, maybe I’ve been lucky or maybe it’s the fact I remove the watch after every workout and wipe it down with a microfiber cloth. I always have done this since my teens long ago when I once removed my casio watch to discover all this gunky grey matter. presumably sweat and dead skin. Yuk.

      My V800 seems so much better material wise, but it’s not my day to day watch so can’t honestly say it’s immune to daily wear and tear

    • Nikos K.

      The Garmin Watches are more Software Reliable, from my personal scope and experience.

      I am owner of M400 and Garmin Fenix 3, since May 2015.

      The M400 is totally mess since firmware update 1.8.4 from January 18…. No firmware correction yet, no solution for the problem. And the worst, no public awareness for the issue.

      No doubt that m400 is a very capable watch BUT it is burned from software issues and VERY long time waiting for corrections….

      From the other side, the Garmin has no such a problem since purchased. And if you search for their software update you will see fast response to any bugs with updates.

    • Pieter Oosthuizen

      I had my M400 since Jan 2015 and durability IMHO is good, no issues. (Apart from the hassle free replacement of the USB port due to corrosion (partly my fault) – one of the reasons Polar did away with the rubber plug)

      To be fair – the Garmin forums are filled with FW issues for many devices, e.g. see link to forums.garmin.com (I moved from Garmin to Polar as their Connect platform was down for weeks end 2014 / start 2015. The Fenix GPS accuracy thread is already running to 213 pages. )

    • Nikos K.

      Garmin, has the ability to revert back to previous firmware if you want to.
      Something polar won’t do, and stay bricked for long long time…

      And as i already said, this is my personal opinion using both brands.

      I don’t say polar is worst, BUT, they already leave me without properly working watch for more than a month. With no instructions or comments for how on earth revert to working firmware. And if, as most people, didn’t own other training watch, i had to face 1 month at least with no training program (Custom Work Out).

      This is not professional and definitely not proper customer care awareness.

    • Pieter Oosthuizen

      Agree :(

  88. Tia

    Thank you for your reviews!! I feel like I can really trust what you say about products, I also really appreciate that after you get sent the product by the company for free, you then go and buy the product to support them.. I think that is stand up and I appreciate that! Which makes me trust you more!!

  89. Christian

    Thanks for your reviews, they strongly influenced my decision to buy the Polar RC3 GPS and recently the Polar M400.

    I am pretty happy with the M400 except for the GPS-based altitude measurement. There is a considerable lag-phase in recording the altitude. When running or skiing in hilly terrain the watch records an increase in altitude although I am in a descent, and vice versa, the altitude decreases although I am in an ascent. The resulting values for the total ascent are therefore considerably underestimated. Is this a general problem for GPS-based altimeters or something specific for the M400?

  90. Yurii Manin

    The Polar M400’s latest firmware update (of February or March 2016) allows to show running cadence​ during runs using internal accelerometer. I have these watches and calculation are pretty accurate and steady. I was running two times with different metronome apps on the smartphone and copmaring results of these apps and the watches. While app metronome shows 180 BPM the Polar M400 shows 91-92 SPM (it counts steps of one leg). Thus taking this slight tolerance in mind you can run withing the 180 SPM sweet spot. Great tool!
    Anyway, the watches are very good. Except for one thing and this must be taken into consideration by anyone who wants to buy them. There is no vibration alerts in them and the sound alerts are VERY quiet. Thus, it’s almost impossible to know what the watches want you to do while running on the city streets. The only way is to repeatedly giving a glance on the screen. If there is a strong built-in vibro in Polar M400, I would rate them very high in the everyday sports use.

    • Pieter

      Did you try to increase the volume?

      “To view or modify sport profile settings, go to Settings > Sport profiles and choose the profile you want to edit. You can also access the settings of the currently selected profile from pre-training mode by pressing and holding LIGHT.
      – Training sounds: Choose Off, Soft, Loud or Very loud.

    • Yurii Manin

      Even with the volume increased to “very loud” on the streets the sound is hardly heard. During interval training lack of vibro must be pretty inconvenient!

  91. GCZ

    I’ve been using M400 for 1,5 yrs and was happy till Polar released soft 1.8.4. Now it’s a mess. I’m really curiuous why there is only one comment in this thread that mentiones this fact. What is more, after recent Polar Flow update problems with interval workouts are duplicated and visible on iPhones.
    May be you DC have some better knowledge what happened and when it will be fixed?

    To be honest buying Polar stuff now is a lottery, thus I don’t recomend it, especially M400.

    • Nikos K.

      And the worst part is, till firmware update back in January, no fix for almost 3 months…..!!!!!

      This is totally unprofessional, especially when polar is aware for the problem as you can see by their respond to my email back in January.

      “On 20 Ιαν 2016, at 13:25, customercare@polar.com wrote:

      Hi Nikos,

      Thank you for contacting Polar Customer Care.

      Unfortunately there seems to be an error there and we are looking into it now. Hope to have it fixed asap. Thanks for your patience.

      Best Regards,
      Global Customer Care/ Anna-Leena
      Polar Electro Oy

    • GCZ

      Should be rather signed…

      Global Customer DON’T Care
      Polar Electro Oy

      We are going Nokia’s way.


    • Nikos K.

      Just think about it..

      I got a sport watch based on features I need and for me custom work out is a killer one feature. I gave 170€ and now I am almost 3 month with out my primary feature…

      The funny ( if not sad ) think about it, is the last sentence in their answer… ” hope we have it fixed ASAP “….

      Maybe I missed the meaning of “ASAP….” Or maybe is my bad English language knowledge ….

    • fotis


      do not complain for the watch.It has many funcionalities at a reasonable price so you cant ask for anything more….i think it has improved since its release (adding many features).

      You can do custom work outs with a simple stopwatch in your hand or bike and just use M400 for heart rate functions , speed alitude etc.

      Mine…after six months usb port wasnt charged and got brand new one as replacement after 7 days.Meanwhile was training normally and keeping notes in traditional way(hand notes on paper) …wasnt an issue…

      M400 has so many features…at 180 euros(with heart rate) to unlock its full potential you must me a gym trainer or personal trainer..every day i am learning a whole new thing about my fitness level due to favor of this watch.

    • Nikos K.

      Hi fotis.

      I got a sport watch for training assistant and work out creation and following.
      If a have to wear 2 watches for proper training and work out sorry but i think this is the most unprofessional situation for polar. The M400 has all those features i need, i am using it for almost 1 year and the firmware error “erase” watch half operability.
      Just can’t understand why on earth Polar do nothing for almost 3 months…

      As i said, i am lucky that i have a Fenix 3 with all my workouts and keep properly training. With no disruptions and other than Optical HR equipment on my body.

  92. Erlend

    Where do I find the “back to start” function?

    • Erlend

      Forgot to say that I have the M400 watch :-)

    • Neil A.

      Log in to Polar flow. Click on your profile, then sport profiles, choose whatever profile you want that feature available i.e. running. Click edit on that profile, click on ‘related to device’ and ensure that ‘Back to start’ is ticked. Save and sync.
      That feature will then be available when you are doing the appropriate workout i.e running. Click the up/down arrows to scroll through and find it.

    • Michael Swann

      It can also be enabled temporarily when training by going into the Quick Menu (press and hold the Light button) and going down to Set location guide on.

  93. CJ

    Cadence from the wrist gives you the option to get your running cadence without a separate stride sensor. Your cadence is measured with a built-in accelerometer from your wrist movements. The get this feature you need to have at least firmware version 1.8 on your M400.

  94. Nolan Barrios

    GREAT JOB! Really appreciate the data analytics in the comparison tool. I’ve been a long time Polar customer and considering switching to the Garmin 230 or 235. Your analysis has been very helpful. Having owned a FS210, SX625/735, RC8000CX (Best Watch), M400; the M400 has missed the mark. And as you have suggested its the Micro USB. The problem is that its really not a Micro USB at all. It is simply a row of pins that correspond in size and shape to accommodate the connector. Of all my Micro USB devices – DROIDs, Kindle Fires, etc they all encase or surround the pins presenting one solid piece. This is where Polar has failed and failed miserably. As you point out with Garmin and their website, take some up front engineering time before GA. The price of this watch and its features are fantastic. However, the few dollars saved on materials has robbed them of these features; both the watch and the software. I am hoping they will replace the watch. But figured I’d reach out and perhaps you can have some influence on them. In my opinion, there should be a total recall of all watches purchased in 2015. That’s the honorable thing to do.

  95. Phil

    I’ve been using my M400 for over a year now, largely on the basis of your review and the good price point. I find it easy to use and it has featured really like including the race completion predictor which I find much easier to use than trying to keep track of a pace – I’m surprised other manufacturers don’t do this. However there are a few things that annoy me. Firstly it doesn’t give figures for the partial lap left over at the end of a run. It doesn’t automatically suppress auto laps when you are running intervals. It would be useful if you could put the backlight on permanently, perhaps at half setting – theses Swedes must run at night too. And when you use the race completion function it won’t show elapsed time, and these screens aren’t customisable. And I have just had the failure to recharge problem – the day before my first marathon so I am going to have to borrow an unfamiliar watch. But despite the niggles is has been a good first GPS watch

    • Christian

      Phil, you can turn on the backlight during exercising. While training, press the light button for a couple of seconds until a menu appears. Scroll down and press ‘Set backlight on’. In this menu you can even access the interval timer during exercise and finish time predictor.

      You can turn off the auto lap function quickly before you start your interval training. During exercise, press the back button, the press the back button for several seconds until a new menu appears. Scroll down and set ‘Automatic lap’ to off. Off course, this is not automatic but still relatively easy to do without starting a new training session.

      Btw, Polar is based in Finland :)

    • Philip Clark

      Thank you! I think maybe I should have explored that menu a bit more, although maybe it would be better to be able to turn the light on before you start a session. However it’s all a bit academic at the moment as I am still suffering the USB fail problem.

    • Christian

      I also found out about these extra menus more by chance. But now I use them quite frequently.

      Have you sent the watch to Polar? They have replaced my M400 and previously my RC3 GPS within a couple of days without any problems and any extra cost.

    • Philip Clark

      I’ve sent them an email. The watch is exactly a year old, and the fact that they had to change the charging port fitting shows they do have a problem with it. I don’t want to have to buy a watch just now as the market is in such a state of flux, and in any case it should last for more than a year before going wrong

  96. Antonis

    Hi, can you please tell me if it shows cumulative ascend (trail running)?

  97. Dan

    I was having trouble installing the PolarFlow software on my Windows Vista PC. To get it to install i had to first partially install websync_2.8.3 which install Polar Daemon and a MS Visual C++ update. Once those were installed I was able to download PolarFlow and install it. Hope this helps anyone else out there with an ancient PC ;)

  98. ryan

    hi everyone

    i would like to start out by saying thank you to ray for doing these reviews they are a huge help and i always look here before making a purchase. i have been using a forerunner 310xt with a speed sensor for cycling and a foot pod for indoor running. i dont use it for swimming so i am not to worried. recently it has not been syncing and i am having trouble with the screen. i have factory reset it a couple times but nontheless i am going to add to it. i purchased the polar m400 yesterday because of rays review of it and also it seemed like it was highly rewarded by several magazines and tech companies. i am currently training for a half marathon and decided to get this because of all of its features and the price point. after reading reviews i am wondering if i should return it. are people still having issues with loosing gps signal, and are they still having issues with the watch falling apart. my garmin after a year barely has a scrape on it

    thanks ryan

    • Nolan


      That’s a tough call. All I can say is that I have an order on Amazon ready to go for a Forenrunner 230, the Sosche Rhythm + Optical Sensor, and the Wahoo ANT+ Speed and Cadence Sensor. This order depends upon how Polar responds to my service request on said M400 thats only 7 months old. And candidly, I will probably just sell the M400, my RC800CX, H6, H7, and WINDs equipment and call it good. So if you want my old ones – I’ll gladly sell both watches, all 3 HR monitors and both external GPS units for a pretty low price. NOTE both the M400 and RC800CX will have been serviced by Polar Direct with very limited to zero use after the service. The M400 with HR is $259 – I will beat that price and then some. Sorry – did not mean to use the post as a 4-sale discussion :-) I can make a contribution to the site if the sell moves forward :-)

    • Luca

      Bought my m400 in december 2014. Used it every day continously since 2 weeks ago (bought an A360 I now use during the day) . Used it in any condition (includind at the sea, swimming or canoeing). The only care I take is not charging it unless sure it’s completely dry. I realized my limited usb sync issues were related to cables; I bought several 10cm. cables and had no issue ever since. Obviously that’s just my experience. The GPS track I see on map is absolutely precise (a few possible mistakes immediately after fix, but activating it a couple of minutes before starting avoids them) only downside I found is that GPS speed is probably an average of the last 20/30 seconds so speed is not useful in case of interval training (HR on the other hand seem just perfect).

  99. 1LightningFan

    Hi Ryan,

    I’ve had my M400 for a year and a half. I wear it every day and use it for running (no swimming or cycling). Personally I’ve not had any issues with it. I dry the watch after running to remove any sweat and leave the port uncovered to let it dry before charging or syncing. In my opinion if you take care of your stuff it should last. In total there are five M400 owners in my family and we are all very happy with them. So, before you ask, no, I’m not interested in selling it. By the way, I’m not sure where Nolan shops but Amazon has new M400’s with the H7 heart rate monitor for under $200.

    Good luck!


    • Nolan


      Makes you wonder why the watch is being sold for 40% off the list price of $259. As I stated in other posts relative to this topic, I have demonstrated my loyalty to Polar having trained and raced using multiple Polar watches. I am glad you and your family have enjoyed a wonderful experience. However, I and others have not been as fortunate. And I can say with a great deal of certainty that I took very very good care of the watch. My issues with Polar go beyond just the M400 having owned 4 other Polar watches. And, please do not assume that people who are having issues are being careless. Had Polar made the PolarTrainer 5 compatible for MAC or integrated PolarTrainer5 with PolarPersonalTrainer than perhaps I would still be using the RC800CX which is a GREAT watch and would not have purchased the M400. Perhaps if the S725 would have been updated to support GPS I would not have upgraded to the RC800CX. Polar has tied great devices (RC800CX) to legacy software with no upgrades and made “fragile” products (M400) tied to better software (Polar Flow and or PolarPersonalTrainer). Good Luck to you and yours and if anyone wants a like new RC800CX it is now listed on Amazon and is in GREAT condition.

  100. Tom

    I have had to watch for one year. I use it for running and biking. I take a shower with it on and only take it off to recharge. I used the rhythm+ heart monitor it’s a perfect match. I have only had to reset the watch Once. Other than that no problems. I bought mine at clever training no taxes free shipping 10% off heart rate monitor was 7999 well worth the money compared to wearing a chest strap. No regrets here my wife also has one and has had no problems.

  101. Ryan

    What is gps difference between m400 and Garmin forerunner 25

  102. Ryan

    What is gps difference between m400 and Garmin forerunner 25. Can’t decide which to get

    • Nolan


      The M400 has more features than the Garmin 25 for a slight uptick in cost. Others may disagree but I would compare the M400 to the Garmin 230. The M400 GPS is pretty good. But I am comparing to other Polar watches vs Garmin. So try compare the Garmin 230 vs the Garmin 25 and that would be a good guide. If the 230 wins – then compare price of the 230 to that of the M400, your budget and thats your answer.

  103. Julia

    Thank you for the review! It really helped me decide to get the M400.
    However being a female athlete, the fact that most in-depth reviews are written by men has left me with some doubts, which unfortunately have been confirmed after wearing the watch for a while.
    I wanted to get the watch as an everyday activity tracker and to track my heartrate and GPS while running, cycling and mountaineering. I am very content with the functions and find them sufficient for many outdoor activities.
    However I have had real issues wearing the watch on a day to day basis as it is not comfortable and feels to big (sometimes even painful) on my wrist. I am not an endurance athlete but I often include cardio into my training routines. For many of my workouts, that include running I would use the timer to run a certain distance and then have a given time that I use to do exercises (of course it would be inconvenient to take off the watch during the exercise sets). Or I would run/cycle to training and back, keeping the watch on during training. After such sessions I often find the back of my hand to be slightly bruised from the watch. These bruises worsen, when wearing the watch at work or during other daily activities. For me this unfortunately means that I can only wear my Polar M400 watch when I go running, cycling, hiking… After that I have to take it off for at least a day (and not wear any other watch) to allow the bruises to heal, or at least feel less painful.
    I am still happy with my decision to buy it as a sports watch, but slightly disappointed because I would have enjoyed being able to wear it all the time.

  104. Nolan

    Update. I too just received my M400 back from service. Good news bad news and why I just sold my complete inventory of Polar items. Polar replaced the entire Micro USB interface. Invoice 19.95 plus 8 for shipping covered under warranty. The watch has three parts; band, housing which includes the USB port, and watch computer. Polar replaced the entire housing with a new USB port. Per my previous post it’s now a complete port i.e.pins encased forming a solid piece. So question, why was the watch made like that from the beginning? Should Polar have recalled all M400s? Based upon my invoice the cost for materials was probably half of 19.95. Labor at the time of manufacturing would be a push. Net Net build the watch right the first time and charge the right price $189.95 or even 199.95. The watch would have been $50 less than similar watches. Instead customers are complaining, and the market value of the watch has fallen some $40…..see Amamzon. So my Fenix 3 Sapphire will arrive tomorrow. I wanted 1 watch that looked like a normal watch. While expensive, the sell of my RS800CX and M400 will offset 75% of cost – a value to have 1 watch that will do most things very well and syncs with MMF Strava and other. I tried to combine a Withings Activite’ Activity Tracker and Garmin Forerunner 230 but based on research the only App that might sync both into a complete combined dashboard was MapMyFitness….and according to them it was doubtful. I want to thank Ray and will contribute to his site. By far he fairly reviews almost everything, is careful, complete, and concise. And, he walks the walk having been and probably still is an accomplished triathlete and I will guess Duathlete and Ultramarathoner…..Thank you Ray and all others who have posted. Closing note for the woman with issues of the M400 being too big. Checkout the Forerunner 230…you can always sell the Polar ;-)

    • Nikos K.

      And last but not least, almost 4 !!!!! months after latest update and polar is unable to fix the firmware problem that cause custom work outs totally unusable.

      Even their own training programs they introduced today, are miss and mesh with M400 and latest firmware… !!!!

      Well done polar !!!! A “pro” company with kids like philosophy and customer care…

    • Nikos K.

      So, i come back to comment with new firmware installed.
      First of all, and most important for me, custom work outs working again. But there are 2 tweaks steps for success.

      Step 1 : Even if you don’t need time based or distance based workout (for example gym work out), you MUST add 1 sec “work step” before “rest step”. For example, my pull bar work out. For M400 to count sets correctly i had to set 1 “sec work” step, 30sec “rest step” and transition from work to rest “manually”. That wasn’t a problem with two versions older firmware.

      Step 2 : After “Warm Up” step you MUST set transition (from warm up to work) to “Manually”, not automatic. If you do leave it “Auto” you will end up with missed and mess work out sets…. Again, That wasn’t a problem with two versions older firmware.

      So after 4 months, polar managed to semi correct custom work out programs. But keep in mind, 2 step mentioned above if you want trouble free Custom Work Out program.

  105. John M Rea

    With footpads on bike shoes, will the M400 now give bicycle cadence?
    The V800 always has; the M400 did not do cadence for even running at first.
    I see this mentioned in the software updates–not otherwise, as far as I have looked.

    Has anyone attempted to measure cadence on a road bike? What results?

    • Jeff

      I have the BT Stride footpod. It works great in Running mode, Walking mode, and other activities.

      Today, I cycled with my running shoes to see if it would pick up cadence from the footpod. Nope. In Cycling mode, it doesn’t even try to detect a footpod. :-(

    • John M Rea

      thanks for doing the field test for the rest of us. Very gracious of you.

    • John M Rea

      It would be interesting to know whether this is a decision by Polar to set the software to block detection when in the Cycling Sport profile, rather than an inherent inability to detect. If it is then there would be a work-around to give you cadence when riding.
      To be more specific:
      —-If you have the footpads on, mount your cycle and put your Polar M400 into running mode, does it then detect the pedaling motion of the footpads and report them as cadence? Report them accurately?
      If it does, then we know that the cadence detection is disabled in software with the aim of protecting the market for Polar’s other two bike computers, which can report cadence.
      —If it turns out that the footpads can return cadence other than when in Cycling mode, then it should be simple to create an alternate sport mode that does not have the name “Cycling” and tell it to collect all the usual data, including cadence.

      I would be curious to see what happens.

    • Jeff

      Hi John,

      I’ll try it tomorrow and let you know.

    • Jeff

      Okay, I tried the Polar Stride BTS footpod in running mode while riding my bike. It does report my cycling cadence accurately. However, after riding 1.8km, it reported my “running” distance as just 0.19km! Strange, as I thought the distance in running mode was based on the GPS (which was on during the test). The route map shows my whole ride, so I didn’t lose signal during the test. So it seems that:

      1) Polar has purposely disabled the footpod detection in Cycling mode, so you can’t use it to measure cadence.
      2) Choosing another sport may not work since other metrics (e.g. distance) are misreported (deliberately?).

      Just for clarity, my M400 is running firmware version 1.8.300.

    • John M Rea

      Well, we don’t have the satisfaction of getting the cycling performance, but we do have the satisfaction of Mystery Solved. Nice going.

      Somewhere out there in the ranks of Polar programmers and marketers, I think I can hear a faint chuckle.

      So it goes, at least until some 14 year old hacker gets one and revises the program.

  106. Melania

    Hi :)

    I’ve been reading your review on the Polar M400. I need a watch that has a good reading on GPS and especially on HR. I have only started running for a year so I’m still learning. I have an offer to buy either a Garmin 225 or this type of Polar. Which one is more accurate on HR? The strap or the incorporated HR in the Garmin as I can tell that they are both ok with GPS. I ran for a while using a Garmin Forerunner 610 which was very easy to use and quite accurate.

    Many thanks for your help!

    • Tim L


      I use both the M400 and FR225 for running. The accuracy of the Polar H7 HRM strap when used with the M400 is far better than the optical HR sensor on the FR225. The FR225 quite regularly displays ‘cadence lock’, where the displayed HR matches your cadence, and also doesn’t work well in cold weather due to low blood flow in the wrist. For these reasons I only ever use the FR225 with a HR strap.

      GPS is comparable under most scenarios, although when there is no GPS signal the FR225 uses the accelerometer to determine the pace.

      If I had to use only one watch I would choose the M400 – more data fields, more customisable, multi-sport support, better HR strap and better customer service. The only notable downsides are that you cannot import activities into Polar Flow, (export only), and no vibration alerts.

  107. john persson

    The best test to read!
    Really down to the buttom with all relevant questions.
    Thanks alot for sharing this info with me, much appreciated.

  108. Health

    I have M400 and have been very pleased with it but I have moved on to running longer distances in the mountain and need more battery life. Polar’s M400 does not last 8hrs in the mountains plus I would like something that last longer than 8hrs anyway but under 20hrs.

    Any recommendation? Garmin 230 and 630 are on my radar. A version of M400 with say 15hr battery life would have been good enough for me.

    • Pieter

      Yes it is pity Polar doesn’t e.g. has an option to customise the recording interval – so I got a Suunto Ambit 3 Run as well…

      I can also see the gradual degradation of my M400’s battery, I could reach ~8h in the beginning, after 1,5y I am glad if I can get 5,5h out of it , and then Polar sticks with the silly function that you can’t start a recording when the battery is on 10% – that is easily 30 mins – 1h left perhaps :(

      The manual states ‘The Polar M400 has an internal, rechargeable battery. Rechargeable batteries have a limited number of charge cycles. You can charge and discharge the battery over 300 times before a notable decrease in its capacity.’

  109. Nikos K.

    So, i come back to comment with new firmware installed.
    First of all, and most important for me, custom work outs working again. But there are 2 tweaks steps for success.

    Step 1 : Even if you don’t need time based or distance based workout (for example gym work out), you MUST add 1 sec “work step” before “rest step”. For example, my pull bar work out. For M400 to count sets correctly i had to set 1 “sec work” step, 30sec “rest step” and transition from work to rest “manually”. That wasn’t a problem with two versions older firmware.

    Step 2 : After “Warm Up” step you MUST set transition (from warm up to work) to “Manually”, not automatic. If you do leave it “Auto” you will end up with missed and mess work out sets…. Again, That wasn’t a problem with two versions older firmware.

    So after 4 months, polar managed to semi correct custom work out programs. But keep in mind, 2 step mentioned above if you want trouble free Custom Work Out program.

  110. Mike J

    I recently did an update to the OS on my Samsung phone (to “marshmello” or some other goofy name) and ever since then I have to frequently cycle the phone’s bluetooth off and on in order to get the M400 to sync with the Polar android app. Just a heads-up to people out there.

    Got my M400 when they first became available in local stores in Wisconsin and the charging port still works (knock on wood). During the workweek I take one to three various loops in the business park, then when I return I slide some paper towel or napkin between the watchback and my wrist figuring it will wick some moisture away. Works for me so far.

    If this watch ever goes bad I’ll probably switch back to a Garmin (whichever model I can afford whenever that happens), but for now it is working well for the most part. Sometimes I’ll get a goofy high HR reading from the Polar strap but probably just a poor skin connection since it seems to self-correct once some sweat forms.

    Anyway, mainly just posting to give a heads-up on issues with the android OS update possibly causing bluetooth pairing problems.

  111. Felix Alicea

    DC Rainmaker:

    I purchased a Polar M400 watch about a month ago. During that time I went for about 8 runs with the watch. Having read your review for this watch I was very careful with the rubber USB plug on the back of the device so that it would not get wet with sweat. Anyway, one day I pressed all the buttons and the watch would not respond. I sent it to Polar Tech support and they repaired the watch and sent it back. They said the device was corroded and to keep the port dry. They replaced the band with one that has no USB plug on it. I called them and they said that this was the latest band and it would be okay. What are your thoughts on this. Is this the latest band? Or are they pulling a fast one? As I said before the band I had previous to the repair had a USB plug to protect it from moisture. Please let me know ASAP since I may return the watch for a refund.

    All the best,
    Felix Alicea

    • It is correct, since roughly September of last year all new units ship without a USB plug/cover/thingy. Apparently the port is better waterproofed now.

    • Felix Alicea

      DC Rainmaker:

      Thanks for the quick response.

      All the best,
      Felix Alicea

    • runnershigh

      Hi Ray, are the new shipped units different in the dimensions than the “older” units?
      Is there any cheap alternative (other manufactor) to the electric H7-HR-Sender that also supports HRV transmitting as well?

  112. Rita

    Hi! How do you set up your name on M400’s face watch?
    Thanks in advance.

    • Moe

      Go to Settings > Watch Settings > Watch Face and then select the “Your name and time” option. You should get a “Watch face changed” message and you should be good to go.

  113. Michiel

    Hi, thanks Ray for the great work on tracking all equipment out there. I wonder if any one has the same issue as I have with the M400 after the latest firmware update; my watch stopped functioning. I cannot upload anything anymore to PC or flow app. Before it was fine.

  114. Ivan


    Bought M400 almost year ago (August 2015) via E-Bay. Now my unit doesn’t charge and slowly dying. But the reason I’m writing: called to service center (Kyiv, Ukraine) and just named ‘M400’, ‘replacing of USB port is USD 50 and half price for localy sold units’ was reply and they didn’t even asked what’s wrong. It was absolutely unexpected for me for a ‘budget unit’.

  115. Hi,
    I encountered a very strange issue a few days ago. I went to our runninggroup training and afterwards I synced my M400 with the Android-app which also automatically syncs with Strava and in Strava everything is private until I make the workout public manually. Last Monday I suddenly got kudo’s for a power-workout in Strava. When I looked I noticed it had the same starting time as my runninggroup training, but only contains heartrate. And the duration of this one was shorter. Strava said that the used device was a V800. I synced at home with no other devices near (and also not connected a V800 before). How can this happen?

  116. Ed

    I just got my Polar M400 which I bought through Wiggle (Internet Site). When I opened I immediately saw that the rubber cover for the USB port in the watch was missing (photo attached) and I wrote Wiggle about it. I got this answer:
    “I confirm that the new Polar models don’t have this cover and are perfectly prepared so water and sweat don’t get in so you don’t have to worry and use it without any problems. I case there is a problem you always can be in contact with us and we will help you to manage the guarantee”.
    I would like to know if that is the case why POLAR still adding a written warning inside the box where the watch comes which reads:
    “Do not charge the Polar device when the USB port is wet or sweaty. Please note the guarantee does not cover faults cuased by charging the Polar device when the USB port is wet” (and they added a BIG admiration mark !)

    What is your veredict DC RAinmaker?
    Thanks in advance

    • Pieter

      See link to support.polar.com

      After having some USB corrosion issues on my early M400 model, Polar refit a new rubber (?) ‘frame’ on my M400 which didn’t have the little plug which might have caused the port to stay damp.

      Enjoy your watch!

    • Jan Vdw

      The port itself is water-resistant, the rubber cap kept it too dry so corrosion occured (had it myself).
      Connecting usb-cable to wet contacts however was ALWAYS a bad idea…
      My routine now: sport, rinse under tap, blow port (and watch) dry using cold/medium setting on hair dryer, then simply connect (with a functioning) usb-cable and sync/charge!
      No issues ever since…
      The connector in the usb-port itself remains poorly designed :-(

    • Ed

      Thanks Pieter, now that I know that is better not to have the port covered I will enjoy!

    • Ed

      Thanks Jan. I will follow your tips!

  117. jonlynch

    Beware of updating the m400 to 1.8.500 firmware (June 7th update) on android 6.0, there is an issue where the M400 cannot be paired (“pairing failed” error) and can’t be synced with Flow app. Even though this worked on previous versions of the polar firmware with the same version of Android. Also the version of polar firmware cannot be rolled back on the m400. My handset with this issue is Moto E Gen2, and I have seen other handsets mentioned on the polar facebook page such as LG G4 and LG G3 with the same problem. Apparently the issue is fixed in Android 6.0.1 but you have to wait for the manufacturer of your handset to role out these updates (which may not happen for older devices) to be able to sync with Flow App.

    Of course there is no mention of this in the polar release notes to warn people of the potential issues of updating the m400 firmware.
    link to support.polar.com

    There don’t seem to be any work arounds to sync from the m400 for Linux users.
    Have any other people experienced the same issue with this version of the firmware.

  118. Nisar Khan

    Do i use M400 polar on different people with one watch by editing height and weight every time… ?

  119. Sharon

    I have a question about the steps measurements.
    How the steps are being calculated ?
    I wake up in the morning , drive to work and it shows more than 1000 steps in “Today’s activity”

  120. Andrew Seidman

    Odd request here. My girlfriend uses an M400, however she likes the interface of Nike run app. The app dynamically adjusts her target goals based on her previous runs. For the life of me I an’t figure out a workaround to get her polar flow data into Nike+. It supposedly works with Garmin so I tried exporting her polar flow data into Garmin, then hoping to sync it with NIKE+, but no dice. Thoughts? Thanks.

    • Mark H.

      If you use an Android phone, check out the SyncMyTracks app, it can synchronise just about anything to anything…

      The online service Tapiriik also synchronises lots of things to lots of other things.

      Hopefully one of those should do what you need!

  121. Janic Wesseling

    I have just bought an m400 for running, cycling and step counting.
    Today i ride with my bike to work for 10 km it counts 3400 steps while cycling?
    Is this normal?

    • Mark H.

      Yup, I see that too. I think it classes all activity as some sort of steps (i.e. using steps as a measure for all activity)… that or it just misunderstands the vibrations through your wrist when cycling.

  122. Shane Manner

    Does anyone know if music control is on yet? The product comparison calculator says no, but Ray posted saying it was going to be added Q2 2015, and I found a Polar press release saying the same.

  123. Timo L

    DC Rainmaker,

    Have you done or are you going to test M400 wrist/accelerometer based cadence accuracy? That feature was added on January version 1.8.4.

    • David

      I don’t know about accuracy but it usually corresponds well to my Garmin FR235. Garmin gives it’s cadence in steps per minute while Polar’s one is in cycles.

  124. Wil

    I apologize if this has been covered and I missed it, but is it possible to see both my current pace and average pace on the same screen? If not, how difficult is it to toggle to a screen with my average pace during a run, assuming that is an option?

    • Pieter

      In Flow – Setting – Sport Profiles – Training View – ‘Speed/Pace’ / ‘Average Speed Pace’ ?

      Remember to Synch.

      (Etc – build up the dashboard as you like)

  125. enrico

    dear all
    tring to increase battery life for an ultra… ( 7 hours and watch is 2 years old).

    i thought of the following:
    – charge full night before
    – keep on airplane mode until start
    – set screen to have text in black?
    – deactivate sounds?
    – deactivate gps at check points

    would you think of anything else?


    • Christian Köhler

      You can use a foot pod and turn off GPS.This will increase battery life dramatically.

      The other option is to charge during the run. M400 can be charged without interrupting the training session. Even a small USB Power bank (those used to recharge smartphones) will recharge the watch several times.
      There are cables with thin cornered micro USB connectors. With one of these you can even charge the watch on your wrist while running.


    • enrico

      thanks Christian!
      looks like cable would the best solution as i would like to be able to record with GPS the whole ´adventure´.
      I tried to look on Amazon.de (race is in 10 days so cannot order from abroad) and could not find an angled micro usb cable flat enough that would let me charge on my wrist.
      Any hint on where i could find it?

    • Christian Köhler

      Something like this (from German Amazon)?
      link to amazon.de

    • Christian Köhler

      I just searched for “‘Micro USB Kabel abgewinkelt” at Amazon.de

      Look at the pictures carefully. It is a difference weather the cable will go to the left or the right, up or down. If you have the “wrong” cable maybe you cannot wear the watch on the arm you are used to.

    • enrico

      exactly…all cables i found so far on amazon.de do not look as if you could wear the watch with the cable plugged in considering the m400 port is below the watch and not on the side…

      i guess i would need something like this (though this is hdmi instead of micro usb)

      link to aliexpress.com

      However the more i search the more i start to doubt it does exist…

  126. Ratacit

    Hi! Thank you very much for the review. Very comprehensive.

    I just bought a discounted unit with the HR and overall I am pleased with its appearance, feeling etc. Prior to using the M400 I only used mobile phone GPS tracking apps. Recently I mostly used my Samsung S7 running Endomondo, an app that I so really like.

    However, there are some inconsistencies between M400 and the S7 Endomondo records.

    I did a long run couple of days ago and here are the readings:

    1) Endomondo

    DISTANCE 31.97 km DURATION 4h:51m:52s CALORIES 2,265 kcal AVG SPEED 6.57 km/h MAX SPEED 12.94 km/h AVG PACE 09:08 min/km MAX PACE 04:38 min/km MIN ALTITUDE 70 m MAX ALTITUDE 242 m ASCENT 603 m DESCENT 573 m HYDRATION 4.66 L

    2) M400

    Duration 04:51:16 Distance 31.06 km Average heart rate 150 bpm Max 221 | Min 41 Calories 4255 kcal 09:22 min/km Average pace Max 04:22 83 Steps/min Average cadence Max 113 45 Running Index Extreme Ascent 1110 m Descent 1085 m

    As you can see the distance difference is about 1K less, the Kcal is almost double, the ascent and descent are also very different…

    Any idea? Is the M400 less or more accurate then a mobile phone? Looking on the Google maps the M400 seemed a little closer to the track. (The M400 is the blue line)

    The price paid was OK (equiv. of ) USD135.

    • Pieter Oosthuizen

      I have many times seen my M400 out with up to the specified 2%, which is quite a pain when you do say a 50. (Yes I know 1km indicated more doesn’t sound like much sitting here typing but when one is tired! :) )

      That and the non configurable recording interval (High Accuracy or OFF) prompt my switch to Suunto Ambit 3 Sport which is a pity as I really really liked the M400, and still wear it as my daily watch. (Just not for running / cycling anymore.)

      PS : I did suggest to Polar to perhaps tune the firmware a bit, and to give us a more options re the recording interval, and the only response I received back is that it was ‘within spec’.

    • Ratacit

      Thanks for the replies.

      I looked at the Suunto Ambit 3 both Sport and Vertical but they are expensive. Worth but expensive.

      I guess I get to live with it as it is. I’ll run more tests and post is here as well maybe it will help others make a decision.

      And yes, one (1) Km more to go after 30 done it sometimes seems a LOT :)

      I also did address Polar but don’t have any reply yet.

  127. Joe Adamson

    I would say the M400 is likely to be more accurate for both GPS and calorie burn.

    1) for GPS it is showing a much smoother track, that may be down to a more accurate GPS track or just a smoothing algorythm,. I had same issue recently between m400 and Nike run club app on my LG G4. The m400 looked much closer to the actual route, much as I would like to think I had run the further distance suggested by the app.

    2). All else being equal, and assuming that you have updated both your polar settings and Endomondo with accurate height weight and gender I would expect a more accurate calore count from the M400 as it had heart rate data to incorporate.

    • mike

      Just a note (that will likely go unread!) to say I was mistakenly told by an M400 agent, that I could input my “real” VO2 max value if I knew the value (I do) That is simply untrue; you cannot input known VO2max results. Instead, you are stuck with VO2max estimates supplied by the M400 software after a “fitness test”. It turns out the VOmax estimates are meaningless, age dependent, approximations.

      The VO2 max values in the M400 are created through a “fitness test” (you lie down for 5 minutes with the unit “on” and it produces an “estimate” of your VO2 max based, apparently, on HR). After taking the “test” my M400 listed my VOmax at 41 when, in fact, it is near 70. But, by lying to the unit about my age and retaking the test several times in the same day, I was able to “trick” the unit into producing a VO2 max of 64, an “estimate” close to my tested VO2 max value.

      What’s going on here? A quick look at the M400 data table for VO2 max (link to support.polar.com) will make it instantly clear that Polar’s M400 producing VO2 max “estimates” rather than real VO2max data. The results in the table – based on tests of 62 “healthy” individuals (a ludicrously small sample size given gender differences and the age related ranges the data purports to describe) – have no absolute, objective, value.

      Perhaps more significant, the M400 algorithm produces VO2 max estimates that vary remarkably with the age you supply in the watch’s “physical settings” – the younger you “are”, the higher the VO2 max estimate produced on any given day.

      If calorie counts are unimportant to your training schedule, none of this will matter to you. But, if you train using HR zones and calorie counts, then VO2 max levels become very important because the M400 calculates your caloric output and “fitness” based on those fabricated VO2max values. For me, the caloric output using the “calculated” VO2 max of “41” were well below (about half) what I usually see in my training (for the record, my previous experiences are with the Polar F7, tool that produced excellent correspondence to lab test results).

      Fortunately, you can work around this flaw by lying to the M400 about your age in the “physical settings”, retaking the “fitness test” and, through iterative testing, eventually produce a VO2 max value that’s close to your lab test results. This approach will, in turn, produce caloric counts and ‘fitness’ that more in-line with expectations based on real lab test results.

    • ratacit

      Can you just go on your ploar.com/flow account, input the VO2max (Fitness Test result), save and then sync your device?

    • Mike

      I’ve dug around in “Flow” (every menu) but found nothing that allows me to do add a VO2max value or a “fitness test” result.

      That’s not to say it isn’t there, but my effort revealed nothing. Maybe you know something I don’t…if so, your guidance would be much appreciated.

    • ratacit

      Hope this can help. Cheers!

    • ratacit


    • ratacit

      I’ve been using it for over 2 months and I am very happy with it. I also was in touch with the support team and was informed that the watch does include the elevation in the trail runs, albeit with the accuracy of the GPS for altitude. The notifications are also quite useful even though limited. Battery life is OK. I can use it for a week without any GPS tracking. If I do 7-10K runs (1-1.5 hours) I charge once in 3 days.

    • Ratacit

      I had issues with my Polar M400 USB. Polar replaced it for free (still under warranty) but they also told me that I should only charge using the USB cable provided. I do use any USB that comes handy when I need to charge and I am not sure what can be so special about the Polar USB cable. I am not even sure it is marked Polar. Anyone here can have a look? I also look at FAQ and indeed they list: “Your Polar device can be charged via computer only with the custom USB cable that came in the box.” whilst for A300 they list: “A300 can be charged through a computer with a standard USB cable.”

      They asked me if I want to buy one for USD6.5. I’ll do it but I’m just wondering… Any comments?


    • Pieter Oosthuizen

      I also had to change USB cables to fix synch issues.

  128. Joe


    Using the desktop version of the site, go to the left hand menu, expand the “account” section and select settings. There is an option to put in your V02max underneath your activity level.

    Hope this helps


    • Mike

      Hey there Joe,

      Thanks for the comment…I followed up on your note and discovered that there is no “left hand” menu. When I open my account it goes directly to the “Diary” (picture attached). I checked all of the other possibilities and did not see any menus on the left hand side.

      That said, you can click on the picture icon (or, more accurately, the down “angle”) and the personal settings page opens up. The VO2 max entry is in that area. Hope this will help you next time.

      Still think the age based VO2 max estimates are a crappy way to handle true fitness measurements.

  129. Joe

    Thanks Mike. I was navigating on my mobile with it set to render as desktop and I found it on a left hand menu. Obviously a quirk of the way they have the site setup to render on different devices and resolutions. Glad you found it.


  130. Adéla Kraklová

    Is it safe to swim with it in a normal swimming pool?

    • Mike Neag

      Yes, it is safe to swim with. Unfortunately, the you cannot record your heartbeat in the water, though you can record the activity and get data – for what it’s worth.

      I’ve been using it and have found it’s much improved over my old Polar F7. The “sync” process works well and the watch produces a lot of information. The VOmax estimate makes the M400s accuracy doubtful….that said, it’s cool to look at the stuff it produces.

      Good luck.

  131. Kaue Pepe

    New firmware, pace and distance from the wrist.

    link to support.polar.com

  132. Brenda

    Hi there, could someone please give me their two cents.

    I’ve been using the M400 for about a year now and with my Samsung Galaxy S5 and I really like it despite the fact that the HR doesn’t go to Strava or S Health if while I’m using it, I’m about to receive a free gift of a Samsung Gear Fit2 because I bought a Samsung Galaxy S7 and my question is (I’ve googled and googled but haven’t gotten very far) should I swap my M400 for using the Gear Fit2.

    I don’t know anyone who uses it so can’t ask them, I run (neither fast nor prettily an not competitively just for me), but I’m predominantly a mountain biker and I like to run/pedal pushing myself using my HR zones where possible.

    Any advice for / against would be greatly appreciated, thanks Brenda

    • Pieter

      Hi Brenda
      I can only give you my opinion, but you need to decide :)
      I suppose it depends on your primary goal for the watch. I can’t see myself doing any sort of activity with the Samsung GF2, as I like more ‘activity oriented’ and customisable M400.
      Just one question if I may – you can see your HRM Zones on the M400 during exercise, and you will also see it after your synch to Strava as well, why do you want to see it on Strava ‘during’ exercise? (Polar has a neat bike mount for the M400 etc)
      On the other hand you CAN link your BTLE Polar HRM strap to Strava to see you HR dynamically while on the bike, but then you won’t see it on your M400 (IIRC) ) Your activity will then be recorded directly on Strava, and it will not be required to by synced to Strava afterwards from Flow.
      How accurate is the Gear Fit 2’s HR tracking? (I personally have my doubts) , as it seems to perhaps be THE most important item of your specific requirement? (Polar’s HRM strap approached ECG accuracy apparently)
      So maybe I didn’t understand your question correctly, as you mentioned 3 products here, but let me know :)

  133. Vitor Santos

    Hi! Great Review!!

    About the pink wristband, do you know if there’s a significant diference on the size of the pink wristband.

  134. Babs

    I purchased an M400 a couple of years ago & eventually the micro usb port became corroded/damaged when it was out of warranty. I am thinking of buying another one as I really liked it but I have seen a couple of references to a new model not having a rubber cover over the port, do you know if this is correct & if so is there a model number so that I can tell which is which when purchasing another one.

  135. Roelie Beukes

    Is the distance measured in a horizontal plane or on the slopes?

  136. SDW

    Hi DCR!

    If I wish to support you via purchases and am in UK (or Fr, quite often…) do you have a link to UK or FR suppliers



  137. ross weir

    Great in depth review, however a word of warning for anyone thinking of buying the M400. The sinc with mobile devices is a known problem for this watch and in my case and may others has proved to be a deal breaker. Carry out research and you will see this is a known fault which has been on going for some time. Without the ability to reliably sinc I would say its not fit for purpose.

    • Johan Germs

      Hi Ross,

      That was caused by the latest firmware update, which was withdrawn by Polar on 24.02.2017. A factory reset solved it in my case.

      Yesterday I updated with the new hotfix 1.9.600 solving the known issues from firmware 1.9.25

    • Ross Weir


      Thanks for taking the time to reply. I’ve sent the watch back for a refund, I’m sure it’s a good product when it’s working but I’m not prepared to except a device which makes you jump through hoops just to get it to work. On a point of principle I wouldn’t want Polar to get any money from me because they are aware of the problems and should either withdraw the product or tell people the truth.

      All the best


    • Art Isgood

      Johan, I see that the wrist based speed distance capability was removed in Feburary. Do you know when it is supposed to be re released?

  138. Skivandal

    Sone awesone Polar concepts that never saw the light of day on the Polar blog today.

  139. Alex

    No vibrating signal?

  140. Deb

    My polar m400 stopped working last month and polar repaired this foc out of warranty, as it was the known USB port corrosion issue. My question is how have people found their watches after repair? Does it last? Am in marathon training and don’t want the watch to fail again when I’m using it heavily.

    • Pieter

      Repaired mine April 2016, still going strong after that. (Bought Jan 2015)
      (But I do rinse and dry now after every run more or less)

    • Bought mine in Feb 2015, got the USB-issue in Aug 2015. Got it repaired and still going strong now. Although I am under the assumption that the 8 hour GPS-recording won’t be reached. When fully charged I get approx. 5-6 hours.

    • Pieter

      Funny that you mentioned battery life – I haven’t done a long run in the past month or so to test bty endurance, but I have a growing suspicion over the past 2 weeks or so that I need to charge more often now, e.g. approx once a week it is getting to 10%, and that is with ~4 – 4,5 h of GPS & HRM usage. (But honestly that is not too bad after 2.5y and many cycles. The battery is apparently not so expensive to replace?)

    • I don’t know if battery is easily replacable. I still have the 310xt around so if I need more batterylife I can always use this watch. Also looking out for the successor of a V800 with optical HR.

  141. Lizz

    I plugged in my polar m400 to charge last night and woke up to this white screen of death. Tried a soft reset as recommended by their website and tried to do a factory reset but the flow sync program won’t even acknowledge that it’s plugged in. I’ve had it about a year, been seriously using it for the past 5 months training for a half Ironman that is next week! I’m wondering if there is a way to fix it or I should cut my losses and get a new watch, and if so, what?

  142. fotis

    Hi guys

    I think Polar must update the firmware of M400 with CHRM continuous heart rate monitoring such as M430.

    • Neil A.

      Hi fotis, do you wear a heart rate strap 24/7 with your M400?

      Measures heart rate from your wrist at regular intervals, day and night”

      No point adding CHRM to the M400 as it hasn’t got an optical sensor.

    • fotis

      I would like to know my resting heart rate anytime i want as a feature but as you said cant wear heart rate strap all day long! :)

      Just eventually check HR is a nice feature and only available on devices with hr with optical sensors.

      Knowing my resting heart rate during day and night is good!

      maybe i give a shoot` wear watch and hr strap all night with indoor cycling as a training mode and check hr graph after the only way but is very uncomfortable! :P

    • fotis

      I did the experiment with indoor cycling mode ( no gps) and saw my heart rate graph during sleep time hr (strap was a bit uncomfortable) but the data is precious!!!

  143. graham alder

    how di i track my sleep with my Polar M 400

    • Peter

      link to support.polar.com

      “Sleep information at Flow webservice and Flowapp
      M400 will track your sleep time and quality (restful or restless),if you wear it at night. You don’t have to turn the sleep mode on,the device automatically detects from your wrist movements that you’re sleeping. Sleep time,and its quality (restful or restless)is shown at the Flowwebservice and Flowapp after M400 is synced.”

  144. Andrew

    Anybody successfully updated their M400 to 1.9.681?
    link to support.polar.com

    • Riaan Louw

      I did last night. Don’t ask me what’s fixed, as I have not checked, or used it since then. The USB charging issue “charging cancelled” is still there though.

    • David

      I updated mine. It no longer syncs with my iPhone at all. I’m giving up on Polar and going back to Garmin.

  145. I think this is what I’ll get for my husband/wife/son/dad/,… a new waterprooflab! I loved the explanations here and thanks so much for your articles. Now I need to choose one of them. the hardest job still. I’ll see what he likes.