Polar's latest fitness band called the A370 is a multi-tasker like the company's older wearables, and at $20 less than its predecessor, it's definitely the better choice. It monitors your heart rate every five minutes, whether you're resting or exercising, unlike the A360 that only does so during workouts. The device can even tell when you're active, so it can give you tips to be able to reach your activity goals. If you run for exercise, A370's accelerometer can estimate your running speed and distance. It also tracks the calories you lose, as well as connects to Polar's weighing scale if you want to use it primarily for losing weight.