Data Stories

Your sleep score looks great. Your body is still running empty.

WHOOP says 87/100. Oura says 92. You feel like a zombie.

Sleep score measures one thing

Sleep trackers measure duration, architecture, and heart-rate variability during sleep. They tell you if you slept well — not if you're recovered.

Your nervous system tells a different story

You can sleep 8 hours and wake with elevated resting heart rate, low HRV, and high stress hormones. The device says 'good sleep.' Your body says 'I'm exhausted.'

What actually predicts recovery

Readiness score (HRV + heart rate + sleep + previous strain) is a better predictor than sleep score alone. But even readiness can miss chronic exhaustion if your stress load is high.

The test: How do you actually feel?

Before you trust the score, ask: can I think clearly? Do I have energy? Am I irritable? If no, no, yes — your body is right. The score is noise.

Screenshot: the honesty check

Sleep score: 90. Readiness: 80. Mood: exhausted. This happens. So what actually proves recovery? Your body composition tells the month-long story sleep scores miss. Data is input, not judgment. Your body's report matters more than the algorithm's.