Why We Sleep

Joe Rogan had a 2 hour discussion with Matthew Walker, author of Why We Sleep. Listen on Overcast. Below are my key takeaways.

Key takeaways:

  1. Sleep 7-9 hours a night.
  2. Effects of sleeping less than 7 hours:
    • Time to physical exhaustion drops by 30%
    • Lactic acid builds up faster
    • Lungs take in less oxygen and let out less CO2
    • Lower peak muscle strength, lower vertical jump, lower peak running speed
    • Higher injury risk
  3. Serious side effects of extended lack of sleep:
    • Men have testosterone level of someone 6-10 years older
    • Cognitive performance suffers greatly
    • A study with one night of 4 hours of sleep saw participants have a 70% reduction in cancer fighting cells (!)
  4. We can’t regain lost sleep with naps.
  5. Our brain demands sleep to replenish our bodies.
  6. Alcohol (and other drugs) keeps your brain from entering REM sleep.
  7. The DTs (Delirium Tremens) an alcoholic experiences are the brain hijacking the waking consciousness and forcing the brain to dream while awake (!)
  8. If we don’t get REM sleep, our brain keeps a record of how much we should have gotten and will cause intense dreams in order to catch up.
  9. When sleeping in an unfamiliar environment (a hotel) only half our brain sleeps, so we don’t sleep as well, this is a defense mechanism.
  10. Many children diagnosed with ADHD may be simply under slept.
  11. Our bodies become resistant to fat loss when we are under slept.
  12. If you’re getting elective surgery, ask your surgeon how much sleep they’ve gotten in the last 24 hours. If they’ve had 6 hours or less, you have a 170% increased risk of a major surgical error (!)