PRICE: £158

The sleek M400 is a running watch and activity tracker (keeping a record of steps, distance, calories and prompting you to move if you haven’t done enough). It uses a chest strap to record heart rate and an inbuilt accelerometer to measure movement and
also calculate cadence, a useful coaching tool to prevent over-striding. Set up is via the Polar Flow website and app, which you download to your computer or smartphone. From there, you set up your profile, configure the data displayed on the watch during training, and plan your training sessions. After your run you then upload your data via Bluetooth to your phone or by plugging the watch into your computer. It is also easy to send the data to Strava. Audible alerts keep you in the right zones, and a wealth of data is available mid-run by scrolling through the screens. A back-to-start function points you in the right direction if you get confused as to where you left the car! One great function is the End Time Estimator which estimates how long it will take to finish your run. At the end of each run the M400 uses what it calls ‘smart coaching’ to tell you the benefit you gained, e.g. improved aerobic fitness or fat burning. It also gives you a Running Index based on an estimation of VO2 max, which you can track over time as you strive to be classed as ‘elite’. It even tracks your personal bests and displays a trophy at the end of your session
if you’ve achieved a new milestone, such as longest run or
fastest kilometre. 


We liked Sleek enough to wear as an everyday watch. Lots of functions and the cadence and End Time Estimator are great coaching features.

Not so hot It’s a little bit fiddly to connect the USB cable to recharge.

Get-faster session Set your target finish time for a given race distance and use the End Time Estimator to ensure you run at the correct pace. Great for doing race pace workouts.


An attractive watch packed with useful training features, and good value for money. Neat enough to wear all day.