Polar M400 Watch

The Polar M400 is one of a new breed of fitness wearables – combining the simplicity of fitness bands such as the Fitbit Flex with the heartrate and GPS activity tracking of high-end running watches such as the TomTom Runner Cardio in one device. And all at a price that is closer to a fitness band than GPS watch.
The first and foremost thing about the Polar M400 is that it’s incredibly slim (11.5mm) and light (56.6g). It is no more arduous or bulky to wear than most fitness bands and is certainly less obtrusive than just about every other GPS-tracking watch on the market.

Quite where its antenna is hidden is unclear, but it’s vital it doesn’t get in the way when you’re wearing a fitness band day and night. The Polar M400 gets this right more than any other rival. That also means that it works better on skinnier wrists. Again, this is in stark contrast to key rivals.

The light weight and low profile may be to its credit, but elsewhere it is perhaps too unobtrusive – and borders on plasticky. The 128×128 pixel, 33mm screen may not set a smartwatch fan’s hair on fire, and the resulting info screens are bereft of design flair or interest. But at least everything’s bright enough to be visible even in fairly direct sunlight and, there’s loads of information on display. There’s a backlight for those late evening runs, too.

The five buttons (up, down, select, back, light) all work well and are designed so you don’t trigger them accidentally. On the back, there’s a micro-USB socket – which means you can travel with one phone and watch cable to charge. You can sync via Bluetooth to a smartphone app if you prefer. The socket is rated to 30m water-resistant without its cover, which may turn out to be important.

The Value

If there is a let-down to the Polar M400’s design, beyond its blandness, it is that both the USB cover and main watch strap – made of similar material – seem worryingly flimsy. It’s that kind of slightly cheap plasticised rubber that can be prone to brittleness.

There was no sign of any tearing, stress or breakage in either during testing, but the combination of the design of the clasp and the rubber may give rise to concern long-term. That said, pins hold the strap in place, so it’s clearly replaceable, and the USB socket is waterproofed without its rubber cover.

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