summary

Lack of sleep is bad for your physical health, your mental health, your longevity, your ability to learn, your creativity, your emotional control, and more.

Our modern environment is terrible for getting good sleep. Bright lights, electronic devices, late-night weekends and drinking all impair your ability to sleep well.

Every single part of your body is enhanced by sleep. This is not hyperbole.

Two forces drive how sleepy you feel:

1. Circadian Rhythm

• A cycling day-night rhythm that makes you tired or alert depending on time of day
• Is internally generated, but affected by exposure to light, activity, and meals
• Melatonin is generated in darkness

2. Sleep Pressure (Adenosine)

• The chemical adenosine builds up throughout the day, causing you to be sleepier the longer you stay awake
• Caffeine blocks adenosine receptors in the brain, but does not prevent the generation of adenosine (this)
• Adenosine levels can only be lowered by sleeping

Two types of sleep:

• Dominates the first half of the night
• Helps shuttle information to long term memory
• Helps turn new physical skills into unconscious motor memory

2. Rapid-Eye-Movement (REM)

• Dominates the later half of the night
• Connects new experiences to distant, unrelated information. This builds creativity and understanding
• Helps forget painful emotions surrounding difficult memories

Alcohol suppresses REM sleep, and causes sedation, not natural sleep.

Stop taking sleeping pills: No past or current sleeping medications on the legal (or illegal) market induce natural sleep