Sleep Is The Single Highest-Leverage Longevity Intervention

The hierarchy of interventions

If I could only recommend one longevity intervention, it would be sleep. Not exercise, not supplements, not fasting.

A single night of 4-hour sleep reduces insulin sensitivity by 30%, drops natural killer cell activity by 70%, and impairs cognitive performance more than a 0.05 BAC.

What good sleep actually means

• Duration: 7.5–8.5 hours in bed
• Architecture: 90+ min deep sleep, 90+ min REM
• Continuity: fewer than 5 awakenings per night
• Timing: Consistent within ±30 min nightly