How does it calculate restful vs light sleep?

[dj9281]

Well some one has already tried to compare it... a good read.. hope it clears some doubts..

Kodierer [Coder]: ZzzZzz - Microsoft Band Sleep Tracking in the Testbed

That's a great article and shows that the band is very innaccurate in the area of restful sleep. It's better with light sleep. So really, it's safe to assume that the sleep restoration and deep sleep values on the band are not accurate and shouldn't be taken seriously.

 

[ThreeMcc]

The only exception to the rule about fitness trackers using just heart rate and movement is the UP3, that uses galvanic skin response (skin conductance) which changes depending on what state you're in.