Gear review: Polar M400 Sport Watch Activity Tracker with GPS

polar-reviewIf you’re a regular reader of Run. Lift. Yoga., you know how much I love testing wearable fitness tech (see here, here and here). I currently own a FitBit Force for tracking activity and sleep and a Garmin Forerunner 110 for tracking and pacing my runs, so when an opportunity to review the beta version of the new Polar M400 GPS activity tracker came up — a sport watch that not only tracks your daily activity levels and sleep, but also your running, cycling and other indoor and outdoor activities — I obviously did this:



I was curious to see how the Polar M400 would stack up against the Force (which has an LED display and tracks activity, sleep and stairs climbed) and the Forerunner 110 (which tracks your runs and heart rate during activity). I like to use my Garmin’s heart rate monitor in conjunction with my FitBit and the MyFitnessPal calorie counting app to get a fairly accurate representation of what I energy I take in and expend each day (see my fat loss experiment here).

First, here’s a little bit about the M400’s features:

I tested the Polar M400 for three weeks, wearing it night and day along with my FitBit Force, and tracked my runs, hikes and indoor workouts with it along with my Garmin. Here’s what I thought:

Dashboard and App

Desktop dashboard view of a training run.

Desktop dashboard view of a training run.

Although I loved the desktop dashboard and how you can really drill down and analyze your tracked activities, view and edit your sport profiles, and compare yourself to other people tracking their running and cycling in the area, I wasn’t a huge fan of the iPhone app in comparison to FitBit’s app. I thought the circle-thing was kind of confusing, and you can’t really drill down into certain hours of the day to see your movement like you can with FitBit’s app.

As the day goes on, the circle-thing is shaded-in based on your activity level.

As the day goes on, the circle-thing is shaded-in based on your activity level.

However, I do like the feature near the bottom where you can see how much of your day is spent sitting, walking, sleeping and moving around in general, and the suggestions of what activities you can do next time to meet your daily activity goals. This doesn’t matter as much to me, but would be an awesome feature for someone looking for more accountability or motivation to get moving.

Look, feel and usability


For a sport watch, the Polar M400 is great. The display is nice and big and it’s fairly user-friendly. I was able to scroll my way through everything and figure out what feature was where pretty quickly without having to read the instruction manual (come to think of it, I don’t think my demo version even came with one). I did get a bit confused about how to pause and save my runs, though — but that’s probably because I’ve used a Garmin for seven years and am just too used to it.

One feature I thought was great was the reminder to get up and move when you’ve been sitting for too long. I wanted it to stop beeping at me so I would always get up when it told me to — and that’s a good thing!

But I'm blogging!

But I’m blogging!

Though it looks great as a fitness watch, it’s not very discreet as an activity tracker. One thing I like about the FitBit is it’s small size and hidden display, so it’s not totally obvious on your wrist. The Polar’s size is also not as comfortable to wear to bed — I found by week two I would take it off at night as it was bugging me.


The FitBit, Garmin and Polar M400 were all very close and comparable for GPS tracking. I wore them all on several runs and the kilometre distance, pace and time were all very close. The only time the tracking was way off was during any activity that didn’t involve GPS, such as strength training or anything indoors; this is where Garmin wins the battle. My FitBit doesn’t have a heart rate monitor, but I am able to go into the app and edit the workout so the calories tracked are more accurate. I couldn’t find a way to do this with the M400, which is too bad. If I were to buy this tracker, I would definitely get the one with the heart rate sensor option.

After an indoor strength training session -- you can see the difference in calories burnt!

After an indoor strength training session — you can see the difference in calories burnt!

As for sleep and daily activity tracking, I found the M400 was a few hundred “estimated calories burnt” per day lower than the FitBit, even though the step count was pretty close for both. That could be because of the underestimation of calories burnt during indoor activities when I’m actually working harder than it thinks I am! The M400 also thinks I sleep more than my FitBit does, which is nice! I think the FitBit is more sensitive to movement at night, so even though I’m not actually awake when I’m moving around in bed, it thinks that I am… which make me looks like a crazy person who only sleeps three hours a night!


Overall, I think the Polar M400 would be the perfect fitness tracker for an endurance sport athlete, or for someone who is just getting into running and fitness and general. I love the daily reminders and motivation to get moving, which is something I find is lacking in other fitness trackers. Though it was missing a few features that I have grown to love with my FitBit — such as syncing with MyFitnessPal, automatic syncing to the mobile app, and a silent vibrating alarm — the Polar M400 is solid sport watch that combines everything you need in one device. As I mentioned above, I would definitely get the heart rate sensor for this watch, so all activities are tracked accurately.

Disclaimer: I was not compensated by Polar to review this product, nor do I get to keep the product as it’s only a demo. I volunteered to test their beta version and write an honest review after three weeks of use.