Sleep Duration
Sleep Duration is a health-education page for Yuelu Body Age. Sleep duration reflects whether recent main sleep has been sufficient, and is one of the core sleep signals in Body Age. Read it as trend context rather than a judgment from one day.
Role in Body Age
Sleep Duration contributes to the sleep dimension of Body Age. Yuelu combines it with the other sleep, activity, and fitness signals so one weak or missing signal does not define the whole result.
Current Yuelu Method
| Field | Current rule |
|---|---|
| Data source | Apple Health sleepAnalysis |
| Lookback window | Valid nights from the last 14 days, using up to the 7 most recent main sleep samples |
| Metric | Average main sleep duration, in minutes |
| Missing-data rule | Missing when fewer than 3 valid nights are available |
Sleep near 8 hours is closer to the ideal range. Regularly sleeping far below 6 hours, or consistently beyond 10 hours, lowers the sleep-dimension score.
How to Improve
- Keep bedtime and wake time as consistent as practical.
- Reduce bright screens, alcohol, and late heavy meals before bed.
- Leave a larger sleep window when training load increases.
- Watch several nights of trend before reacting to one short night.
When Data Is Missing
Check Apple Health permissions, source priority, Apple Watch battery and wear time, and whether the relevant samples were recorded recently.
Rule Basis
- Yuelu Body Age follows the current in-product calculation rules for sleep, activity, and fitness signals.
- Data is read from authorized Apple Health and Apple Watch samples when permission is granted.
- Interpretation is for wellness education and product explanation, not medical diagnosis.
Disclaimer
This material is for health education and product explanation only. It is not medical diagnosis or treatment advice. Consult a qualified clinician for persistent symptoms or health concerns.