The Longevity Index

Sleep

The TL;DR

Sleep is the single most powerful lever for longevity, cognitive performance, and metabolic health. Poor sleep accelerates aging, impairs immune function, and increases all-cause mortality. This protocol synthesizes evidence from sleep science into actionable steps.

Accessibility Level

Level 1 (Foundation): Low cost, high return on investment. This is non-negotiable for anyone serious about longevity. Master this before moving to Level 2 interventions.

The Protocol

Phase 1: Light Exposure (Circadian Entrainment)

Your circadian rhythm is controlled by light exposure. The goal is to anchor your master clock with bright light in the morning and darkness at night.

Morning (Within 30-60 minutes of waking):

  1. Get 10-30 minutes of natural sunlight exposure
    • Direct sunlight is 10,000+ lux (even on a cloudy day)
    • Indoor lighting is only 100-500 lux (insufficient)
    • Face the sun (no sunglasses), but don’t stare directly at it
    • If sunlight is unavailable, use a 10,000 lux light therapy box

Why It Matters

Morning light triggers cortisol release (good in the morning!) and sets a ~16-hour timer for melatonin production. This anchors your sleep-wake cycle.

Evening (After sunset): 2. Minimize blue light exposure 2-3 hours before bed

  • Use dim, warm lighting (red/amber spectrum)
  • Enable blue-light filters on screens (f.lux, Night Shift, etc.)
  • Consider blue-blocking glasses if screen use is unavoidable
  • Avoid overhead lights—use lamps at eye level or below

Phase 2: Temperature Regulation

Your body needs to drop its core temperature by 1-3°F to initiate sleep.

Environment: 3. Keep bedroom temperature at 65-68°F (18-20°C)

  • Your body dissipates heat through extremities (hands, feet, face)
  • Use a fan for air circulation
  • Consider a cooling mattress pad (e.g., Eight Sleep, ChiliPad)

Pre-sleep: 4. Take a hot bath or shower 60-90 minutes before bed

  • The subsequent drop in core temperature after warming up promotes sleep onset
  • Aim for 104-109°F (40-43°C) water temperature
  • 10-20 minute duration

Phase 3: Behavioral Interventions

Sleep Schedule: 5. Maintain consistent sleep-wake times (within 30 minutes, even on weekends)

  • Your circadian clock thrives on regularity
  • Aim for 7-9 hours of sleep opportunity
  • Track with an Oura Ring or similar device

Pre-Sleep Routine: 6. Implement a wind-down ritual (60-90 minutes before bed)

  • No stimulating content (news, social media, intense exercise)
  • Light reading, journaling, meditation, or breathwork
  • Avoid caffeine after 2 PM (half-life is 5-6 hours)
  • Avoid alcohol (fragments sleep architecture, suppresses REM)

Sleep Environment: 7. Optimize the bedroom for sleep

  • Darkness: Use blackout curtains or a sleep mask (zero light)
  • Silence: Use earplugs or a white noise machine
  • Air quality: Consider a HEPA filter to remove allergens
  • Mattress: Replace every 7-10 years; invest in quality

Phase 4: advanced Tactics (Optional)

Supplements (See Supplement Basics):

  • Magnesium Threonate or Glycinate: 300-400mg, 30-60 minutes before bed
  • Apigenin: 50mg (chamomile derivative)
  • L-Theonine: 100-200mg (promotes relaxation without sedation)

Avoid Melatonin Long-Term

Melatonin is useful for jet lag or shift work, but chronic use may downregulate natural production. Use sparingly (0.3-1mg, not the 5-10mg doses commonly sold).

Breathwork:

  • 4-7-8 Breathing: Inhale for 4 seconds, hold for 7, exhale for 8. Repeat 4 cycles.
  • Box Breathing: Inhale 4, hold 4, exhale 4, hold 4.

Evidence Matrix

SourceVerdictNotes
Huberman Lab✅ Strongly Recommends10-30 min morning sunlight; avoid bright light 10 PM - 4 AM
Peter Attia (Outlive)✅ Strongly Recommends”Sleep is the most important pillar of longevity”
Matthew Walker (Why We Sleep)✅ Strongly RecommendsTemperature drop and circadian regularity are critical
Clinical Consensus🟢 High EvidenceSleep deprivation linked to Alzheimer’s, CVD, all-cause mortality
Andrew Weil⚠️ NuancedSupports sleep hygiene but emphasizes individual variation

Key Studies:

  • Irwin et al. (2016): Sleep deprivation increases inflammatory markers (CRP, IL-6)
  • Xie et al. (2013): Sleep clears beta-amyloid (Alzheimer’s protein) via glymphatic system
  • Walker et al. (2017): Sleep deprivation reduces natural killer cell activity by 70%

Measuring Success

Track these metrics with an Oura Ring, Whoop, or similar:

  • Sleep Latency: Time to fall asleep (goal: <20 minutes)
  • Sleep Efficiency: Time asleep / time in bed (goal: >85%)
  • REM Sleep: 20-25% of total sleep (critical for emotional regulation, learning)
  • Deep Sleep: 15-20% of total sleep (critical for physical recovery, growth hormone release)
  • Resting Heart Rate: Lower RHR indicates better recovery
  • Heart Rate Variability (HRV): Higher HRV indicates resilience to stress

What "Good Sleep" Feels Like

  • You wake up naturally without an alarm (or just before it)
  • You feel alert within 15-30 minutes of waking
  • You don’t need caffeine to function in the morning
  • You can maintain focus and energy throughout the day

Connected Concepts

  • Exercise: Exercise improves sleep quality but avoid intense workouts within 3 hours of bedtime
  • Diet: Food sensitivities and blood sugar spikes can fragment sleep
  • Supplement Basics: Magnesium, apigenin, and theanine for sleep support
  • Heat Exposure: Sauna use can replicate the temperature drop effect
  • Cold Exposure: Avoid cold plunges close to bedtime (raises core temp temporarily)
  • CGM Protocols: Nighttime glucose spikes correlate with poor sleep quality
  • Blood Panels: Low vitamin D, magnesium, or iron can impair sleep

Biomarkers & Tracking

  • Wearables: Track sleep stages, HRV, and recovery metrics
  • Blood Panel Guide: Test for deficiencies that affect sleep (Vitamin D, magnesium, ferritin)

Common Pitfalls

Mistakes to Avoid

  1. Inconsistent sleep schedule: Going to bed at 10 PM on weekdays and 2 AM on weekends wrecks circadian rhythm
  2. Alcohol as a sleep aid: It sedates you but fragments sleep architecture and suppresses REM
  3. High-dose melatonin: 0.3-1mg is effective; 5-10mg may cause grogginess and receptor desensitization
  4. Late caffeine: Even 3 PM coffee can reduce deep sleep by up to 20%
  5. Relying on “catch-up sleep”: Sleep debt accumulates and cannot be fully repaid

Implementation Checklist

Start here and build the habit over 2-4 weeks:

  • Set a consistent wake time (7 days/week)
  • Get 10-30 minutes of morning sunlight within 1 hour of waking
  • Cut caffeine after 2 PM
  • Dim lights and reduce screens 2 hours before bed
  • Keep bedroom temperature at 65-68°F
  • Use blackout curtains or a sleep mask
  • Consider magnesium glycinate (300-400mg) 1 hour before bed
  • Track sleep with wearable device for 2 weeks to establish baseline

Further Reading

  • “Why We Sleep” by Matthew Walker: Comprehensive overview of sleep science
  • Huberman Lab Podcast, Episode #31: “Master Your Sleep & Be More Alert When Awake”
  • Peter Attia’s “Outlive”: Chapter on sleep as a longevity pillar
  • Sleep Foundation: sleepfoundation.org

Last updated: 2025-12-30

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