Why We Sleep
Cover of Why We Sleep by Matthew Walker
Rating: 🔟
Why We Sleep is a solid 10. It brings the science of sleep into the modern world and keeps it relevant despite getting a bit too scientific and wordy. Matthew Walker shares his wealth of knowledge in this hefty book, well worth the money it costs. The book has made me reflect on my personal sleep habits especially how much sleep I get across busier periods of the year too!
Matthew Walker has received some flak for his claims in his book, particularly around the scientific data and results presented. Some review of Why We Sleep have been extremely critical about the "facts" presented. But nonetheless, I still appreciate the book in its entirety.
About Matthew Walker
Matthew Walker is the founder and director of the Centre for Human Sleep Science and a proclaimed 'Sleep Diplomat'. His TED Talk, "Sleep is a Superpower", was one of the fastest to reach 1M views and he has also appeared on the Joe Rogan Podcast, BBC and CBS to share his knowledge, that he's accrued over 20 years of research and 100 scientific studies in sleep.
Dr Walker started out studying Neuroscience at Newcastle University and obtained his PhD in Neurophysiology at the Medical Research Council in London. He followed that by becoming a Psychiatry Professor at Harvard Medical School and is currently a Professor of Psychology and Neuroscience at University of California, Berkeley.
Dr Walker took four years to create his International Bestseller, Why We Sleep, with the aim to "reunite humanity with sleep". All of his claims in his book are backed by an abundance of research and findings from his vast amount of experience in the field.
Summary
Why We Sleep is split into four parts (in my own words); Defining Sleep, Effects of Good/Bad Sleeping Habits, How Humans Sleep and the Ideal Practices for Good Sleep, Modern Day Sleep Disorders.
The book starts off by establishing and detailing basics of "Sleep" or as he says "demystifies the beguiling thing called sleep". He also immediately jumps into pressing findings around caffeine and alcohol intake and its effects on sleep; some surprising spoilers, it's bad for your sleep at night.
In the next section, Dr Walker continues to outline benefits of good sleep ranging from mental health to physical health and builds up towards the third part to address sleep routines and habits. In this section, he lays down the tips and tricks on keeping sleep as a priority and the groundwork to have a good night's sleep.
Dr Walker tops off his book addressing 21st century issues such as blue light radiating from devices to medical sleep pills to "aid" sleep and the hustle and grind mentality that is endangering sleep. Another spoiler, blue light from your phones, tablets and TV is also bad for you.
Top 5 Takeaways
Humans have sleep cycles and they are ever-changing.
The best example of this is how teenagers magically gravitate towards sleeping later. This gives rise to the phenomenon that teenagers are predominantly "night owls" and that adults tend to be "early birds".
Think sleeping in on a weekend can "make up" for your lost sleep during the weekday?
Think again, lost sleep can never be recovered. Missed sleep is forever gone and that includes the potential immediate benefit emotionally and physically.
Caffeine and alcohol (and certain medicines) destroy sleep and reduces its efficiency.
The basics of coffee: Caffeine contains a chemical that prevents melatonin receptors from working.
This doesn't make you feel energised, rather it makes you not feel tired. Taking coffee within 10 hours of bedtime can reduce sleep efficiency greatly because of its effects on melatonin and how it triggers our sleep response.
Alcohol on the other hand, reduces the efficiency of sleep as it causes more instances of waking up across the night. This leads to humans not being able to complete full sleep cycles and interruption through the night.
Good sleep before and after studying or any mentally strenuous activity can improve performance.
Sleep before the activity prepares the brain to receive information and proper sleep afterwards helps the brain to retain the information it's just learnt.
A night of sleeplessness puts us in as bad a state as being drunk; emotionally, physically and mentally.
Diseases linked to lack of sleep:
Lack of sleep increases the chance of getting diabetes.
Lack of sleep increases risk of getting heart disease by up to 300% for individuals with less than 6 hours of sleep.
The reproduction system shuts down to preserve energy for core body functions for survival.
Immune system is weakened. This can be so bad to the point where flu vaccinations are not useful and the body doesn't even develop antibodies.
An individual with lack of sleep has increased risk of developing cancer as well as an increased rate of cancer growth.
Top Tips for Better Sleep
Create a sleep schedule with a ritual, including a wind-down routine. A wind-down routine gets your mind and body into sleeping mode. Humans are creatures of habits after all.
Avoid caffeine and alcohol before bed, by up to 10 hours. Both of these substances increase instances of wakefulness through the night and actually reduces time slept and efficiency of sleep.
Avoid eating and drinking large quantities of food and drinks too close to bedtime. Too much food, late at night, diverts the body away from proper sleep.
Avoid naps or sleeping late in the afternoon. Sleep, longer than 20 to 30 minutes, resets melatonin in the body that is used to trigger sleepiness at night.
Get proper sunlight exposure throughout the day. The body responds to sunlight by properly releasing melatonin based on the circadian
Build an ideal sleep environment
Low light environments trigger melatonin release. The less light there is, the more melatonin the body releases.
Be gadget-free at least an hour before bed. Blue light from modern day gadgets reduce melatonin release. This is because the body thinks that blue light is "sunlight" and halts any melatonin production.
A cold bedroom helps the body go to sleep. This is from thousands of years of evolution where humans have gone to sleep when the sun is down with little light and the temperature is lower. The ideal temperate ranges from 15°C to 19°C (60°F to 78°F).