Sleep

Your Sleep score is how much of the sleep you needed you actually got last night, tempered by how efficient and well-structured that sleep was.

We reprocess the raw sleep stages your watch records (deep, REM, light, awake) rather than using its own figure. Against that we set your personal Sleep Need, which rises a little after a hard training day and when you have been carrying sleep debt across recent nights.

A short nap or a partial capture is not counted as a night, scoring a fragment as a full night would be a wrong number.