Sleep is when your body repairs, your brain consolidates memories, and your immune system recharges. Chronic poor sleep is linked to nearly every major disease. Optimizing it is one of the highest-leverage things you can do for longevity.
Key Insights
The 7–8 Hour Sweet Spot
strong evidenceA large-scale study in the European Heart Journal found that sleeping fewer than 6 hours per night is associated with a 13% higher mortality risk. Most adults need 7–8 hours for optimal function.
Sleep & Alzheimer's Risk
strong evidenceDuring deep sleep, the glymphatic system clears beta-amyloid plaques from the brain. Chronic sleep deprivation has been linked to significantly higher Alzheimer's risk in longitudinal studies.
Consistent Sleep Schedule
moderate evidenceGoing to bed and waking up at the same time every day — even on weekends — is strongly associated with better sleep quality, improved mood, and healthier metabolic markers.
Temperature Matters
strong evidenceYour core body temperature needs to drop by about 1°C (2–3°F) to initiate sleep. A cool bedroom (18–19°C / 65–67°F) can dramatically improve both sleep onset and sleep quality.
Quick Tips to Get Started
- 1
Keep your bedroom cool, dark, and quiet
- 2
Stop screens 30–60 minutes before bed (or use blue-light filters)
- 3
Avoid caffeine after 2 PM — it has a half-life of 5–6 hours
- 4
Create a wind-down ritual: reading, stretching, or journaling
- 5
Get morning sunlight within 30 minutes of waking to set your circadian clock
🤓 Fun Fact
“Humans are the only mammals that deliberately delay sleep. Every other species sleeps when their biology tells them to. Maybe they're onto something.”