Beddit

Fitness trackers didn’t always monitor sleep, but the feature is now a sought-after staple in most devices, as sleep is just as important as exercise to a healthy lifestyle. Most wristbands monitor sleep now, and there are even specialized devices that go on your head or bedside table that can also keep track of how long and how well you sleep each night.

But sleep tracking isn’t as simple as step tracking, and you need more than a simple accelerometer to measure it accurately. While motion is an indicator, it’s not the only metric you should track to get a full picture of how well you slept.