📖 Why We Sleep by Matthew Walker
Topic: Sleep | Rating: 4.5/5
Outline
This book explains the biological process of sleep, why we should sleep, REM (rapid eye movement or dreaming state) sleep and strategies for better sleep.
Why I read this book
To optimise my health and energy.
Three keynotes
There is so much information in this book it was quite hard to pick only 3 points. If I ever meet you in real life, I can bore you to sleep with the rest. 😆
1. Sleep is regulated by your circadian rhythm
Our circadian rhythm determines our sleep-wake cycle and is approximately 24hrs and 15mins. It is constantly reset by cues including sunlight and is unique to someone’s age and chronotype. Which explains why some people are “morning larks” or “night owls”. Hence different people have optimal times to sleep and to be alert/productive. So, work with your biology, don’t fight it.
“The average duration of a human adult’s endogenous circadian clock runs around 24 hours and 15 minutes in length.” (Walker 2017)
2. REM sleep regulates your emotions
REM (rapid eye movement or dreaming state) sleep deepens memory consolidation by attaching emotions and creating unique connections. It also allows you to process your emotions, including traumatic events. And our emotional intelligence is what allowed humans to become the dominant species.
One reason why I stopped drinking alcohol is that after a big night I experience anxiety the following week. In this book I learnt that alcohol does not help you have natural sleep – it sedates you. And it blocks your body’s ability to produce REM sleep which can cause paranoia and hallucinations. So, this really clicked with my own experiences.
“A key to what we call emotional IQ depends on getting sufficient REM sleep night after night.” (Walker 2017)
3. Sleep debt can never be fully repaid
We only have one chance to consolidate our memories from the day. Which explains why it is difficult to remember what we crammed from those all-nighters before a test.
Even our body’s ability to produce antibodies in response to a vaccine is a one-time event influenced by the amount of sleep leading up to the vaccine.
“In terms of memory, then, sleep is not like the bank. You cannot accumulate a debt and hope to pay it off at a later point in time. Sleep for memory consolidation is an all-or-nothing event.” (Walker 2017)
Thoughts/reflections
We all know we need to get enough sleep, but to know the “why” helps reinforce the behaviour. Sleep is a crucial pillar of health and well-being. The book hypothesises how sleep allowed humans to become the dominant species. Well, I know after a good night of sleep, I am ready to dominate the day.
Tip: Focus on strengthening the depth, duration, continuity, and regularity of your sleep. The number one recommendation is to have a consistent sleep and wake time, every day. More strategies are explained in the book.
Recommendation
I recommend it for anyone who needs more discipline around their sleep routine. If you’re always tired or dependent on caffeine to function this is a great investment in your health and well-being.
