Sleep tracking including deep sleep via Band

How does Band determine what is deep sleep and what is times awake? Somehow it feels not correct and I wonder if my understanding is incorrect.

Also on the activity on the band face itself, what is purple bar indicate and what are the blue vertical lines?


The band has motion sensors.

If you go into the app and press the “Activity” icon, it will open a new page with stats. There you can select “Sleep”, and at the bottom is a explanation of the colors.


Thanks for your detailed reply. I see the colors on the app and they make sense. But I was wondering on the band itself. There is a big purple box and then blue spikes. The app has different colors.

Also, I wonder if the activity tracking is correct. e.g., this morning I woke up and walked from room to kitchen and back to room. Physically it is around 30 steps. Plus/minus 2 steps. But the band shows 3.

Then I woke up in the night to go use the restroom and the band doesn’t show any timea awake at all. I think the motion sensors and algo are not yet tuned or accurate.

hopefully when they update the sleep page in the app it will be more helpful. I’m using the beta app & the colors match, purple for deep sleep & light blue for sleep. I toss & turn alot at night & the graph on the band clearly shows that. I assume the light blue spikes indicate movement, whereas the purple no movement possibly? Maybe the band is using HR too to determine deep vs regular sleep. I too would like to see a better explanation on how it determines sleep vs deep sleep

I think the colors are the same, but the app is showing them in smaller increments.