Polar's new A370 fitness-tracking wristband is a course correction from its predecessor, the A360 , which was lacking in a few key areas. The A370 improves upon the last-gen model, with continuous heart-rate monitoring, GPS (sort of), an easier-to-fasten band clasp and a new sleep-tracking tool...

Large; colorful display; Accurate heart rate-tracking during outdoor workouts; Useful sleep insights; Waterproof

Connected GPS can be unreliable; Battery life could be better; Too expensive for what it offers

I'm a recent Polar convert. Ever since reviewing the M430 in October 2017 it has been a faithful companion on one wrist on race day. Aside from being a generally brilliant running companion, it also does a great job of highlighting when other wearables I'm reviewing aren't pulling their weight.

Polar is a company known, historically, for making heart rate sensors and hardcore GPS tracking watches - but its new fitness tracker, the Polar A370, is far more mainstream.

Phone notifications; Can GPS track runs with the help of a phone; All-day HR tracking

Only 2-day battery life with all features switched on; Chunkier than the competition; GPS not in-band

I had high hopes for the Polar A370. The Polar M430 is one of the best things I've ever put on my wrist . True, that's not an enormous list, but I have reviewed a lot of wearables, and the Polar M430 has passed the test of time.

The Polar Flow app is excellent; Micro-USB charging

Overpriced; considering its features; Questionable build quality; Unattractive design; No GPS

Heads up – April 8th, 2019! The Fitbit Alta HR (the one with the optical HR sensor) is currently $40 off – down to $89 (or Amazon here )! This is the best price we've ever seen for this unit, and the lowest price we've ever seen for a HR enabled mainstream activity tracker.

Polar's new A370 premium fitness tracker has some small but important feature upgrades over the A360: It adds 24/7 continuous wrist-based heart-rate tracking and the company's Polar Sleep Plus analytics.

Adding continuous tracking heart-rate monitoring to its list of features, the A370 is a modest upgrade over the earlier A360.