Sleep 3.0 · Chapter 3 · 1 min read
Deep sleep
The part of the night we measure most closely.
Deep sleep comes in the first half of the night, in long slow waves. It is the stage we look at most closely in the Sleep Impact Report, together with REM, heart-rate variability and resting heart rate.
We do not promise more of it. We measure it, before and after, with your own device.