In , David Foster Wallace describes the lopsidedness of competitive teen tennis players, the forearm of their stronger sides having grown out of proportion relative to the rest of their bodies. I remembered that passage as I looked at the Polar M600 dragging my left side ever closer to the earth, wondering whether I, too, would wind up with one enlarged arm after reviewing it. The $329.95 M600 fitness tracker is a hulking beast, and I say that as someone who's hardly a petite little thing. It measures heart rate during activity, and it's sturdy, made with high-quality materials, and well designed—if you're six-foot-three. Because it's also an Android Wear smartwatch, it can do some neat things that other trackers and running watches can't, which makes it an intriguing option for anyone who can deal with its size and shortcomings. Design, Display, and Battery Life The emphasis on high-quality materials, such as Gorilla Glass and a soft silicone band, is immediately apparent with t...

Polar's latest and most impressive device to date is a three-in-one runner's watch, fitness tracker, and smartwatch. It has an optical heart rate monitor and is fully waterproof, but cramming in all that functionality means big hits on battery life and wearability.

High-quality build; Built-in optical heart rate monitor; Runs modified version of Android Wear; Waterproof; Works with both Android and iOS devices

Bulky; Short battery life; Occasionally high heart rate readings in testing; Can't set a custom activity goal

Throughout the past few years, we've had to choose one or the other – fitness trackers or smartwatches . Dedicated fitness trackers might be better at tracking your daily activity and heart rate, but they normally lack things like voice commands and proper notification support – two features...

Accurate activity and GPS tracking IPX8 water resistance Two-day battery life Plenty of third-party fitness apps (thanks to Android Wear

Large; bulky design Display is a tad small compared to the overall footprint Software can be buggy at times Should be ~$100 cheaper

For an Android Wear smartwatch with fitness chops, you can currently do no better than Polar's M600. It offers the most intuitive third-party integration with Google's wrist-based OS we've seen yet, and the comprehensive set of workout options should be exactly what most generalist gym visitors are...

Built-in GPS; Robust fitness tracking; Waterproof

Screen shows scan lines; Not the best-looking smartwatch; Poor battery life on iOS

Polar isn't short of know-how when it comes to sports watches; its M400 GPS Running Watch was one of our all-time favourites. The M600 is altogether a different wrist-based wearable.

Comfortabe to run with; Accurate GPS and HRM; Water-resistant

Silicone strap picks up lint and fluff; Poor-quality display; Charging is slightly fiddly

While we were disappointed with Polar's first attempt at wrist-based tracking with the A360, we found the M600 to be extremely accurate when compared to a chest-strap. We did multiple runs with either a MyZone or Wahoo chest-strap on and the M600 never let us down.

Great Polar Flow integration; Battery life is great; Android Wear fitness apps

Design is bland; Quite pricey (for a Polar; No auto activity detection

The Polar M600 is a near-perfect combination of smartwatch and fitness tracker, blending both worlds into a true multi-functional device that is easy on the eyes and easy to use.

The explosion of smartwatches and fitness trackers has thrown up some real gems and thrown down some real turds, leaving us all to step carefully when choosing a new device. Polar is an established name in fitness devices, one of the oldest, perhaps, when dealing with heart rate monitoring.

Solid design; Sports takes priority over smartwatch; All of Android Wear's functions; Polar Flow does so much; Respectable battery performance for a smartwatch; IPX8 waterproofing

Design could be more exciting; Swimming could be better served; Heart rate can be a little erratic; Price

Delivery was fast, product working fine. Keep it up!

Great tracker.. previously used jawbone

There's no shortage of Android Wear watches to choose from. Companies including Huawei, LG, Casio, and Fossil all have smartwatches that run on Google's wearable operating system, and all of them can use Google Fit's activity tracking.

Bold; bright touchscreen display; Onboard GPS and space for local music; Rated IPX8 so you can swim with it; Android Wear will add useful features and notifications for those connected to an Android smartphone

Bulky design makes it hard to wear all day; Heart rate monitor can be slow to catch up to high pulse rates; Expensive for what it offers; Not worth the money for iPhone users when they can get the comparable Apple Watch Series 2 instead