The release of the Polar M400 marked the advent of the now increasingly blurred lines between your standard affordable fitness trackers and the sophisticated workout gadgets that only the most hardcore athletes can afford. As the more affordable version of the Polar V800, a serious sports watch for those really into fitness, you get almost as much of the tracking capabilities and functionality with only a fraction of the price. What they sacrificed wasn’t internal tracking, but rather syncing with a dozen different accessories and other monitors that even dedicated gym junkies don’t use.

While functionality and features look to be completely on point, how does the Polar M400 stack up in the increasingly crowded world of fitness tracker-sports watch hybrids?


The first thing you will notice about the Polar M400 from the pictures is that it kind of looks like a sports watch would have looked like in the 1980s when everything was bigger and bulkier. However, the pictures actually lie. The Polar M400 doesn’t take a great photo because that large display screen makes it look like it sits like a lump on the wrist when, in reality, it is quite thin. It actually ends up more unobtrusive on the wrist than many other GPS-enabled trackers these days.

The screen itself could have benefited from less labeling that gives it a bit of a Casio-esque look and takes away from the display. As for a display itself, the 128 by 128 pixel, 3mm screen could also benefit from not only a touch of color every now and then, but less of the cheesy graphics. Clearly if you are cycling, you know you are doing it and you don’t need the like cyclist on the screen to remind you. Thankfully, most of the time the Polar M400 sticks to the numbers, which is the bit we want to see and the bit that actually looks fine on a black and white screen. It even features not only backlighting so you can see it in the late evening, but you can easily read the screen in direct sunlight too.

The rest of the watch’s interface is fairly straight-forward. It comes with five buttons (up, down, select, back, and the light) on the side and they are not so compact that you have trouble hitting them, but they also are built so they are hard to trigger accidentally as well.On the flipside of the display also sits the micro-USB charging port which is covered by a flap, but even without the flap it is water resistant of up to 30m.

Finally, as for the band itself, there is nothing particularly groundbreaking about it. It is made out of the same polymer of other fitness tracking bands so you get that nice flexibility, but it also feels decently sturdy. The M400 comes with the standard watch clasp which makes for a nice snug fit and so that you don’t have to physical cut and measure the band like some other Polar models


If the Polar M400 was just a fitness tracker, it would be rather unremarkable. However, while it can do much of what fitness trackers do, it also has the great added benefit of being an activity tracker as well.

True to a fitness tracker, you wear the Polar M400 all the time and it tracks your steps, calories burned, how many flights of stairs you climbed, and your sleep. However, unlike many fitness trackers, you don’t need to tell it when you have gone to sleep, it knows. It also senses when you have been inactive for too long and sends an alert to both your phone and your app. It also guilts you in to moving since if you don’t do so within the time limit, it leaves a bad mark in your daily diary.

All of this data is sent into the app, but you can also read it just as easily from the watch interface. The benefit of checking the app is to really see the long-term statistics after daily use so you can make adjustments accordingly. However, while the app is nice, it often feels like it doesn’t go deep enough. There isn’t much reason to check it more than every few days.

All that is pretty standard, but when you press the center button on the Polar M400, that is where it really shines. From the menu, you choose an activity, press start, and the built-in GPS signal from the watch logs you until you stop. Why is this so special? This feature allows you to get the most accurate calorie readings on your body as well as track routes and other metrics in the app. Since the Polar M400 takes things like height, weight, and gender into consideration, it easily gives the most accurate calories-burned estimates of any fitness tracker

The one downside of this? You need to have the Bluetooth HRM strap in order to get those beautiful accurate calorie readings. The fact that Polar, a company that makes heart rate monitors, wearable ones at that, comes with GPS, but not a built-in heart rate monitor is almost kind of insulting. While you won’t get the same accurate calorie count, you will still get activity-specific metrics like how many laps you swam or how far and fast you ran, which is nice, but it still feels like you are getting half a product.

Finally, the battery life is a major boon considering that so many screened, GPS-enabled models can drain down so fast. If you are using the GPS non-stop, you have about eight hours of battery life. However, without ever turning the GPS on, you have a very solid 24 days on one charge. For people that go for long or multiple runs, swims, or cycles per day, the battery might need daily charging. However, as a fitness bracelet, it has some superior battery life to it.


If you are going to throw down the cash to get a fitness tracker-sports watch hybrid these days, there are some things you expect. Once you get above a certain price range, you expect heart rate monitoring and GPS. What you shouldn’t expect is to buy an accessory for one feature to work. That is the real major pitfall of the Polar M400.

It is a great fitness tracker, and it could have been an amazing one if you didn’t have to throw down extra money to make it complete. It is likely the external chest strap makes it so it can get its extremely accurate readings from the way it sits on the body, but even without it this fitness tracker would still likely get it pretty close.

Pin It on Pinterest

Share This