Matthew Walker – Power of Sleep
Shane Farnam’s Knowledge Project
Very dangerous to stay in bed a long time while awake, because brain then associates wakefulness with bed
Go somewhere else, read, relax
You wouldn’t sit at dining table waiting to get hungry
Caffeine
Benefits of coffee are similar to benefits of sleep, but it’s not the caffeine, it’s the coffee BEAN bc it provides majority of daily antioxidants
Health benefits are similar with decaffeinated coffee
Keeps you awake (5-6 hour half life)
Caffeine accumulates over time
Not only can caffeine make it harder to fall asleep, but it can wake you up during sleep cycles
It can also decrease deep sleep from 20-40%
Alcohol
Helps you sleep but due to its sedative properties – it’s not healthy
Can spike your nervous system, produces sleep fragmentation (wake up multiple times)
Alcohol reduces REM sleep and growth hormone production
REM is good for creativity and emotional stability and hormone production
Even one glass of wine in evening can measurably impact sleep
Insomnia
4 types (eg, sleep onset insomnia, sleep maintenance insomnia)
Chronic grade insomnia – consistent symptoms for 3 months
Causes?
-30% heritable (genetic)
-stress & anxiety
-excess caffeine
-physical pain
Common cause of insomnia is hyper arousal – hyper alert nervous system (fight or flight branch) – the “tired & wired” phenotype
First line treatment is CBT (cognitive behavioral therapy) – benefits last longer than eg sleeping pills
1. if you’re awake, don’t stay in bed
2. don’t get anxious / angry, re-appraise and just tell yourself you’ll rest in bed, relax, even if you don’t fall asleep
3. constrain bed times (eg, instead of spending 2 hours tossing and turning, go to bed 2 hours later) – increase sleep efficiency. Longer you’re awake, the more sleep pressure there is. Teaches brain to become hungry for sleep
Temperature
A key regulator of sleep
Hunter gatherers fall asleep a few hours after sunset, and before sunrise (not at sunrise) when the temperature begins rising
When you feel most sleepy – your core body temp is dropping the fastest (1 deg C)
During sleep onset, blood swells to hands, face, feet – so paradoxically you’re warming up to fall asleep
Warming hands & feet can help you fall asleep
Mammals don’t have hair on hands and feet because it’s designed to radiate and release heat
That’s why hot baths and hot showers help – it’s because your extremities are hot, and your core body temp plummets (!)
As you approach waking up, your body temp rises
Part of why coffee helps is because it warms the body in the morning
Quantified self / Oura rings
He tracks with Oura ring and is advisor for them
Orthosomnia – anxiety about improving sleep that it’s self-defeating, becomes mal-adaptive
Sometimes the reports have placebo effect – if tracker tells you you had bad sleep, it can affect your cognitive performance
The best sleep tracker is the one you use consistently
Useful metrics
–sleep efficiency is most important (90%+ is good)
-balance of REM and non-REM sleep
-sleep latency (how long it takes you to fall asleep) – need a balance, if fall asleep too fast then you probably have a lot of sleep debt
His blog addressing questions and criticisms:
https://sleepdiplomat.wordpress.com/
Made claim that lack of sleep doubles risk of cancer (should have been “certain kinds of cancer”)
3 things that ensure bad sleep: Caffeine, Alcohol, and Nicotine
Importance of mental health – anxiety and stress
Sleep chronotypes – are you morning type or evening type?
Everyone has their own 24 hour Circadian rhythm – individual variation in peak and trough
Important to match chronotype with bedtime – eg, if you naturally sleep and wake late, then don’t force yourself to sleep and wake early
If you’ve had a bad night of sleep, don’t change your habits the next day eg, sleep earlier, drink more caffeine, take a nap
Keep a consistent routine
Importance of a wind-down routine – just like for kids
eg, shower, meditation, light stretching
If you nap, nap before 1pm, and keep them brief (10-15 mins)
Don’t count sheep – it’s a myth
Can make you take longer to sleep
What does work – take yourself on a mental journey (like a mental hike, a mental bike ride) – take mind off itself
Don’t look at the clock! It’s not your friend