Polar M400

9.2 score
[Editors rating (9.2)] = (TheGearHunt) score (9.2)/10

Editor rating: 9.2 / 10
User's rating: based on 0 user ratings
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Editor’s Conclusion
Polar M400 Review Facts

Excited to start a new workout routine or training for a competition? The Polar M400 can be your personal coach by giving you your data information to motivate you to the next level. The GPS, 24/7 monitoring and smart coaching will allow you to see your levels of activities. With the Flow app you can plan your training out and analyze your results. Achieving your goals is what it is all about.

The heart monitor gives you the most accurate read by being attached to your chest. To read your most efficient levels and motivate you to perform at your best this system has one of the highest ratings. The price is considered in the lower range for this type of technology. Invest in yourself to make the most of your training or workout time with the Polar 400.

Editor's Pros & Cons

Tracks GPS, heart rate and daily fitness

Accurate and consistent results


Easy to use

For the price has excellent features


USB cover is flimsy

Heart Monitor is a separate piece from watch


There is no limit to the activities you can use this system for tracking. It can track your daily movements and sleep to intense training sessions. Run, walk, swim or bike it has you covered. Even general indoor and outdoor settings for a variety from HIIT to Yoga. Being waterproof you can leave it on all day long and just take off to charge it.

Basic Features

Having the M400 you are able to monitor daily activity and levels. To get the most accurate reading you need to set up your personal information like age, weight, sex etc. Once that is set up you are ready to use it. It will track your daily activity from step count to intense workouts done throughout the day. You can set interval timing which times your work and recovery phases. The watch and monitor system are designed to allow you to know the level and effectiveness of your workouts. When not set to an activity it will display the date and time.

The HR monitor is a separate unit strapped to the chest that is wireless and Bluetooth compatible to measure your levels. It will automatically register to your watch for instant results. The system is one of the most accurate as it is a direct chest read compared to other monitors that are built into the watch that are not as accurate.

Advanced Features

Polar Stride Sensor is great for the runners that want to improve their performance and technique. You can see the distance and speed, whether you are running on a treadmill or on a muddy trail. To break it down it measures your stride length and cadence. It is a sensor that fits on your shoelace which is shock and water resistant.

The GPS feature can be as simple as mapping your routes to being very detailed. It can break down distance, average pace, elapsed time, calories burned and overall ascent. Using this with the app you can actually see the map/route layout.

Polar Flow App is used to view your data and detailed activity levels. It also can be used as a planning guide and diary. Giving you your results with an easy layout while being accurate.

Sleep Tracking lets you know how restful your night was. This tracking is not seen on the watch however it is viewed on the app.

The heart monitor can be used with your smart phone via Bluetooth. This is a great feature in case you forgot your watch but still want to get in your workout and have it tracked. There is also the ability to get alerts for received messages and incoming calls.

Alerts can be set to your preference such as audible alerts while running so you know your mileage without looking at your watch. If you have no movement or decreased movement an alarm can notify you to move around to keep activity levels where you set them.


Overall there is good connectivity however the GPS sometimes takes a few seconds to register depending on your location. The connectivity runs at a high consistent rate which means that as you are running you don’t get blank spots that other monitors get. What that will do is give you a higher level of accuracy.

The other part of connectivity is the system itself. The H7 works simultaneously with your watch to make it spot on at any point of your workout. This means you can keep on moving while quickly seeing your current levels with a quick glance on your watch. Other systems are not as accurate as they don’t use a chest strap. The other difference is other styles make you stop and tap or connect units for it to read levels.


The Polar Flow app is what is used with the watch to view your results. The app is easy to use and setup. It allows you to glance at your training data after each session. The Flow Sync Software is what links the data between the watch and the web service. You will be able to see daily, weekly and monthly results. The app is designed to allow you to plan out your training. Having a plan saves time and stress.

Polar Flow allows you to see as little or as much detail that you want. It allows for even the person that is not computer savvy to use it easily. The Polar Company invested in the app to be fully functional with ease of use. Once you set it up you will find yourself playing around in it to find the results you need.


The wrist band and the chest unit are both flexible for comfort and movement. The watch is slim styled and fits nicely on the wrist for all day wear. The chest monitor is lightweight and compact which fits nicely under your gear. Once you wear it a few times you won’t even know it is there.


The Polar M400 has a slim retro style watch that has high functionality. The band is a soft white flexible band that forms to your wrist and is comfortable. The screen can be seen clearly and is big enough that while doing your activity is clear. It can be worn daily without looking to sporty.


Polar M400 have been creating monitors for years and know a thing or two about durability. With the active person in mind, the watch and monitor system are created to withstand wear and tear. The band is flexible yet durable to prevent cracking or stretching. The face has a slight rounding to it to prevent the edges catching on items like other square models might. Users say that the screen stays clear of scuffs and scratches even with daily use.

The H7 heart rate sensor is designed to last the life of your watch as well. The hard casing protects the components and sensors while the band is a durable strap to secure to your chest. The sensor and the watch are easy to clean and is recommended to do often. We all know that sweat build up can prevent proper function as well as smell. The straps of the monitor can be washed with mild detergent and should be air dried completely before use. The monitor and sensors should be wiped and dried prior to use. The watch band can be wiped down with a clean damp cloth daily or as often as needed. Most recommend doing this each time they charge it to get in the routine.


Having a watch that can monitor your current activity level and be able to see it without stopping your activity sets this apart from other monitor systems. The smooth slightly rounded face molds into the band making it have a slim sporty look. The dot-matrix monochrome style has a retro look but allows you to see the numbers and information extremely clearly. Other types of screens have a style that the numbers and figures are so small you have to stop and raise to your face to read. The M400 can easily be seen in while in your natural form of running or activity.


The Polar M400 has a high quality band that is comfortable and durable. The lightly rubberized band is flexible to form and move with your wrist. It has the traditional buckle and hole strap to adjust to your personal preference. This allows those with a brawny to the very thin wrist user the ability use the same strap. The stainless steel buckle and double type strip allows the extra to be tucked in and is very durable.

Ease of Use

The M400 and H7 are amazingly easy to use. There are only five (5) buttons to operate the watch. The H7 just as simple, strap it on your chest and make sure your sensors have good contact. The app called Polar Flow has so much data compiled to help you assess your activity levels that it might seem intimidating. It is extremely user friendly to set up your plans, check your diary and look at daily activities.


A great feature of the M400 is that it is chargeable. Other brands or styles require battery changes that you have to ship in the watch to have done. When you first get your M400 you will need to charge the battery. It recharges with the USB included using your computer. If you want to charge in a wall outlet you just need a USB power adapter which are very inexpensive. This allows you to charge it if you are on a trip and don’t have access to a computer.

The H7 monitor has a user replaceable battery. This means you are able to change it safely while maintaining the water resistant features. This is a nice feature to not have a delay is use others might have due to having to send it in to change a battery.

The battery life has an average of 8 hours for GPS and HRM tracking and 24 hours of life for fitness tracking only. This is great for your longer runs or activities. If you are a runner in training you know that you might do a distance run and then do a deep stretch yoga session afterward that this monitor will last the duration. The heart monitor can be worn during the run for accuracy and you can either take that off for the next activity. The watch will keep on monitoring the activity. Going for a swim after a run, go ahead keep on the monitor to get accurate results for the whole workout. This is ideal for the active person who likes to know their target ranges and level of workouts.

To extend the life of your H7 battery it is recommended to detach the monitor from the strap after use. The sensors being wet or damp can keep the monitor sensors active which will drain the life. This also means after washing to be sure it is dried all the way. The other recommendation is not to put it in a gym bag near wet or damp clothes and towels.


Polar has priced the M400 lower in comparison to others on the market. The accuracy and features that this system offers are at a high level of technology without paying the high price. The basic system can be used on its own to get great results however the additional accessories you can pair with the M400 can get you specific tracking for your purposes.


There are other accessories such as smaller bands for the H7. The band that comes with it fits most users however if you have a smaller frame you may want to invest in the smaller band. There are bands that you can purchase in a wide range of colors to match any outfit.

Polar Stride Sensor is great for the runners that want to improve their performance and technique. You can see the distance and speed, whether you are running on a treadmill or on a muddy trail. To break it down it measures your stride length and cadence. It is a sensor that fits on your shoelace which is shock and water resistant.

Key Features

GPS activity tracking
Daily activity fitness tracker
8hr battery for GPS and HRM
24hr battery for fitness tracking only
30 M water resistant
Polar Flow App that is easy to use

Bottom Line

The Polor M400 outshines other monitor systems on the market. For the price you get a high level of product and technology that remains easy to use. It is comfortable, has a clean simple style that is incredibly accurate. The features such as the Polar Flow app, GPS, Sleep tracking give you the ability to put your fitness at another level. With an easy to read display you can see your current levels, set alarms to notify you of distance or goals you have set. If you are going to spend your time doing a workout or training session invest in a trusted brand like Polar to be able to see your effectiveness of your workout.