Polar M400

By Laura High @healthwriter61
December 23, 2016

This fitness watch is an effective tool to improve your running game but can also be used to track and improve many more activities.


Polar’s M400 is a serious piece of equipment that generates the kind of detailed information true fitness enthusiasts and data geeks are seeking. By wearing this sizeable watch-inspired fitness tracker, you are announcing yourself as someone who is serious about fitness, or data, or both. The functions on this tracker support more than a passing interest in how many steps you’ve taken in a day, and are really geared toward people who are already training competitively, or those looking for a device that will support their efforts to get to the next level. The M400 even analyzes your data and offers tips and insights based on your recorded data.





The M400 wears like a sport watch. It’s big — really big — which has its plusses and minuses. On the positive side, the screen has enough real estate so you can easily see what’s displayed, even if you find reading small type challenging. I like that because I don’t see small type well and have needed reading glasses to see the display on other trackers. Working out with readers is inconvenient, so I appreciated the fact I didn’t need them with the M400.

The drawback of having such a big tracker is simply that. If you’re a smaller person like me, the size of the thing is a little overwhelming. I also found it somewhat challenging to get on and off. The rubber strap, although comfortable once on, is pretty stiff and hard to maneuver through the buckle.

Navigating the M400’s various screens is pretty intuitive using the five buttons on either side of the device. A nice feature is the button that lights up the face so you can see the progress of your workout, the time, or a notification if you’re in dim light or the dark.

Comfort and wearability

As stated previously, the M400 is large. It’s not something you put on and eventually forget you’re wearing. It’s also designed to track your sleep so you’ll need to wear the device 24/7 if you want that data, but the size and weight made me feel claustrophobic, and I became eager for a reason to take it off.


The M400 comes in five colors — if you buy the heart rate sensor, a chest strap that adds $50 to the $179.95 price tag of the band alone. If you buy the band without the heart-rate monitor, it just comes in black. The look of the device says “I’m sporty” about the wearer. It’s not elegant, and there aren’t options for wearing it more discreetly as there are with some other trackers.


The number of third-party apps available to sync with your M400 is limited. In addition to the Polar Flow app, the M400 also syncs with MyFitnessPal and Apple Health.

Email and notifications

You can receive the same notifications on the M400 that you receive on your paired smartphone, including those from your social networks and groups you have joined or created around your fitness activities. The M400 is compatible with both Android and iOS.


YOU MIGHT ALSO LIKE: Garmin Vivosmart HR


Battery life

How often you need to charge the M400 will vary depending on the features you’re using and the temperature. If you’re using both GPS and heart-rate monitoring, the M400 battery may only last about 8 hours. Additionally, the battery will be drained more rapidly if you’re using it in temps below freezing. If you’re just using it to tell the time and track your daily activities, a single charge can last up to 30 days.

Maps and GPS navigation

Polar does a great job of helping you find routes and keeping track of routes you use regularly. There is even a “relive” function on the web app that shows a map-based video of a training session, including information like where you ran the fastest and worked the hardest.

Fitness tracking

The M400 is specifically geared toward runners, although it tracks much more. Polar offers a number of training programs for runners that can be customized for your event — 5K, 10K, half marathon, for example. The training program can then be further personalize based on your fitness level, goals, and date of your event. All training sessions include a warm up, exercise, and cool down. After you’ve created the program, sync it to your device and start training.

The smartwatch has the option for creating a sport profile for up to 20 activities. In each sport profile you can edit automatic laps (duration- or distance-based), training sounds, and heart-rate information, which of course requires you to have the heart-rate strap. Each sport profile can also be edited to show different details about your session time, environment (altitude, ascent, descent), body measurements (heart rate, time in target zone, calories burned), distance, speed, and cadence.

The Activity Benefit function tracks your day and categorizes every minute as either resting, sitting, or low-, medium-, or high-intensity activity. You can then look at the number of minutes you spent in each category. There’s something eye opening about seeing that you spent more hours on a given day sitting than you did sleeping. Thankfully, one of the options is a notification to move. You can look at the resulting stats by the day, week, or month in the Polar Flow app on either your phone or computer.

A feedback function provides insights and helps motivate you to meet your goals. You need to wear the band more than 10 hours a day for at least 5 days to get feedback from the app. To get the most out of the data, I recommend viewing it from the account you will create at Polar.com. Here, your data is compiled and displayed in easy-to-understand graphs and charts you can view in various ways to make them most meaningful to you.

Software ease of use

I was surprised that, to get started with the M400, I had to first go to my computer. For most fitness trackers you only need to download the associated app to your smartphone, and the web application is usually optional. You can download the app and sync the device to your phone after you’ve created an online account. As clunky as this seemed at first, it was nice to have the online account and access from my computer for reasons mentioned in the previous paragraph.

The M400 is a fitness tracker specifically designed for runners, but with the capability to provide tons more data and insights about nearly every other aspect of your life. If you’re someone who approaches fitness casually or engages in a wide variety of activities, this may be overkill, but if you’re looking to get as much information about your activities and health, the M400 may be just right for you.


YOU MIGHT ALSO LIKE: Microsoft Band 2


December 23, 2016