The 80/20 of sleep: why most athletes get this wrong
Forget eight hours as a goal. The variables that actually predict recovery are different — and easier to control.
"Get eight hours" is the worst sleep advice in fitness. It's an average, not a target.
Consistency beats duration
Going to bed and waking up at the same time every day has stronger effects on circadian regulation than absolute hours. A consistent 7 beats a varying 8.
The first 90 minutes
Most slow-wave sleep — the kind that drives recovery — happens in the first 90 minutes. Disruptions here (alcohol, blue light, late meals) cost more than disruptions later.
Temperature and darkness
Sleep onset is gated by core temperature dropping. A cool room (16-19°C) and complete darkness aren't comfort preferences — they're prerequisites.
Caffeine's long shadow
Caffeine has a 5-6 hour half-life. A 3pm coffee leaves measurable caffeine in your system at 11pm. If you're struggling with sleep, this is the first thing to cut.