Polar M400 Review – For Exercisers Who Wants The Benefits


Detailed Route map – with summary duration, distance and calories burnt.

Daily Activity Summary

Graphical Summaries

Polar M400 Watch Image Gallery


Top Alternatives

Next Model UP


The next model up from the M400 is the Polar V800 reviewed here. The biggest difference between the two is probably the addition of MULTISPORT support in the V800.

They are both almost identical physically (the V800 has a more attractive/expensive alloy metal case) and everything the M400 does, the V800 also does.

If you want to be able to record ONE FILE with bike/run or swim/bike/run etc (all in the same file with discipline breakdown, transition times etc) then go for the V800.

Next Model DOWN


For those who run looking for something slightly less technical than this model, Polar have their M200.

The Polar M200 is 24/7 activity tracker with wrist based (strapless) heart rate and built-in GPS. For a majority of runners and recreational exercisers the Polar M200 could be the better (and cheaper) option. 

For those with less focus on running on more on exercise and well being Polar have the Polar A300 reviewed here. 

Best from the Competitors

The Polar M400 is one of my favorite GPS watches for runners, cyclists and anyone who partakes in sporting activities, indoors or out. The one thing that puts some people off the M400 is the need to wear a chest strap to acquire your heart rate. Personally, I still prefer a chest strap because they offer near 100% accuracy for near to 100% of the time. However, there is no doubting the convenience of wrist based heart rate monitoring. With this in mind, the best alternative to the Polar M400 (other than the M200) is the Garmin Forerunner 35 and, for those happy wear the chest strap, the Forerunner 25.

  • Forerunner 35 review – wrist based heart rate, no chest strap required
  • Forerunner 25 review – similar functionality, chest strap acquired heart rate

Great for HIIT

This Polar M400 is also highly recommended to anyone undertaking a HIIT (High Intensity Interval Training) programme due to it’s 5 x easy to read HRM training zones.


Polar M400 suitable for 90% of exercisers

During our test it soon became apparent that we were testing Polar’s new No1 heart rate monitor / GPS watch for the biggest chunk of the market. It’s such a complete product it really does appeal to 90% of exercisers. At less than £120 (or under $160) for the HRM version it’s not hard to see why this has become an instant hit.

The M400 is for the indoor / outdoor exerciser who wants to keep an eye on daily training patterns, ensure optimal training and recovery. At the same time, the M400 user may want to measure performance metrics like running / cycling speed and distance plus optional heart rate from the Bluetooth HRM sensor.

The M400 is Polar’s most popular heart rate monitor / speed and distance monitor competing head on with the Garmin Forerunner 220 / 230 and even the Forerunner 620 / 630 as an all round sports person’s watch without the MULTISPORT functionality of the Polar V800 / Garmin Forerunner 920XT.

Smart Notification Update (June 2021) : The M400 now has the ability to support smartphone notifications from iOS 8 devices and Android devices running version 5 or later. An alert message is displayed on the watch display when your phone receives an email, text, call or diary event. More details will follow shortly. If you own a Polar M400, please be sure to keep up to date with the latest M400 update notices.

Could Have Been Better?

The M400 is brilliant. Louise has really enjoyed wearing it day in, day out. Lou’s a gardener so she really have put the watch through it’s paces. A normal day for Louise is 44,000 STEPS !! Both of us give high praise to Polar for the M400. For those looking for something like a Garmin Forerunner 620/220 it makes a nice alternative. It also features activity monitoring, something the Forerunner 220/620 don’t have.

If we had to ask for ONE change… just like the V800, it would be useful to have a DAILY ACTIVITY GOAL. We both found that we were achieving our goal in the week… but MASSIVELY OVER-ACHIEVING at the weekend. Most people have certain days they try to train. The ability to set a daily goal would be great.

Review Summary

It was easy to award the Polar M400 a solid 5/5 star review rating as it’s such a complete and competent GPS training watch. The one thing I must say is it’s NOT just for RUNNERS. It’s brilliant for those that run. but it’s equally perfect for anyone else looking to track speed & distance with chest strap heart rate. For the CYCLIST it supports pedal cadence sensors making it ideal for the cyclist looking for a wrist mounted GPS bike computer. Polar have recently launched the M200 with wrist based heart rate, however, the Polar M400 remains a firm favourite of mine and will do for some time …

On another note, something to check out is the polar a370 waterproof capabilities and the Polar M600: cardiocritic.com/fitness-watches/polar/m600-review/

Andrew Wyatt

Andrew Wyatt

Andrew Wyatt has been a tech geek for as long as he can remember. Whether it's laptops, cameras, or projects, he's obsessed with it all. When he's not researching the latest tech products, he likes to go on long hikes with his dogs.

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