Sleep analysis: understand duration, efficiency, deep sleep and REM

It's more than 'hours slept'. Vita breaks down your sleep structure so you can see whether the problem is falling asleep, too little deep sleep, or an irregular schedule.

• Duration & efficiency: time actually asleep vs time in bed
• Deep / REM split: the stages for physical repair and memory
• Sleep debt: your recent accumulated shortfall
• Consistency: how regular your sleep and wake times are

Faced with a screen of sleep data, what do you actually check? Vita's layout mirrors the triage order:

• Step 1: efficiency — below 85% means time in bed isn't converting to sleep. Slow to fall asleep (stress / caffeine / screens) or waking through the night (alcohol / temperature / noise)? The per-night detail shows where the wake segments cluster
• Step 2: structure — efficiency fine but still tired? Check deep and REM share: deep under ~13% means the body isn't repairing (alcohol and late training are common causes); low REM usually tracks short nights and early waking
• Step 3: consistency — decent single nights but a jagged weekly trend? Bed times drifting ±1.5 hours hurt recovery as much as short sleep. Vita's weekly view is built to expose exactly this pattern

In Vita, sleep is not an isolated tab. Last night's sleep flows straight into today's Recovery score; your long-term sleep trend is one driver of Body Age; and the AI coach reads it whenever it answers 'what should I do today'. So the payoff of fixing your sleep shows up in three places at once — recovery climbing back, the sleep driver of your Body Age turning positive, and the coach's advice shifting from 'catch up on sleep' back to 'push'. That's using sleep data, not just looking at it.

WHOOP records your sleep; Vita helps you use it — viewing sleep alongside recovery, training and Body Age as trends, and letting the AI coach give concrete adjustments based on it. Without a WHOOP, Apple Watch sleep data supports the full analysis; with both, they merge and de-duplicate automatically and overlapping metrics trust WHOOP.