My 7 Takeaways from Why We Sleep by Matthew Walker

Sleep is the Swiss Army Knife of Health!

Matthew Walker ruined my life. I don’t think I have ever had this much anxiety. For the longest time, I slept late, struggled to wake up, and felt comfortable cutting from my sleep to squeeze just a little more work, learning, or exercise into my day. I thought that is what successful people did. And I did not overthink it. Where the competition is stiff, you use every advantage you can have. Right? Turns out — wrong. After reading this book, I started paying more attention to the amount of sleep I get. And now, every time I sleep less than 7–8 hours for some reason, I get a deep sense of anxiety about what I just did to my health and well-being. Thank you, Matthew Walker.

That said, thanks to this book I realized that the single most effective way to achieve longevity, secure physical and mental health, prevent and recover from injuries, maximize my potential, and improve learning is sleep. That simple. Or as Matthew Walker puts it: “Sleep is Mother Nature’s best effort to counter death”. Sleep is the best performance-enhancing drug there is. Thank you again, Matthew Walker.

Sleep is Mother Nature’s best effort to counter death — Matthew Walker

Sleep is one of the secret weapons of Roger Federer, one of the greatest tennis players of all time, my favorite. His longevity in professional tennis is legendary, he continued to be a feared competitor on the tour and won a Grand Slam at the age of 37. As recently as 2020, at the age of 39, he reached the semifinals of the Australian Open. You have to be in top physical shape for such a feat. According to Federer, the key secret to his longevity as an athlete is sleep. He tries to sleep 11–12 hours per day, including an afternoon nap.

If I don’t sleep 11 to 12 hours per day, it’s not right. If I don’t have that amount of sleep, I hurt myself. — Roger Federer

Kobe Bryant, one of the greatest basketball players of all time was, for a long time, on the opposite side. Bryant, known for what was called the “Mamba Mentality”, famously slept only 3–4 hours every night. His work ethic was legendary. Players tell stories about waking up very early only to find Bryant having finished his workout before others would even wake up. But even Kobe Bryant realized at some point that his sleep habits were unsustainable.

“What made the lightbulb come on was when I went out there and played the game and played like crap. And I was like, ‘Why am I playing like crap?’ Because I’ve been practicing these same moves over and over and over. But yet, I couldn’t execute them properly. I was feeling sluggish, I was feeling lethargic, and I knew it wasn’t because of my training because I had trained obsessively. Maybe the fact [I was] sleeping two, three hours a night had something with the fact [I was] playing like crap.” — Kobe Bryant

This brings me to Matthew Walker, who is a professor of neuroscience and psychology and has been widely recognized as a foremost expert on sleep, appearing in multiple interviews and podcasts. His book Why We Sleep has become one of those books that I recommend right and left and in this article, I am going to share my seven key takeaways from Why We Sleep by Matthew Walker:

1. Sleep is essential. 6-hours of sleep or less is the straight path to physical and mental problems and a shorter life. Depriving yourself of sleep is a path to heart attacks, cancer, diabetes, physical injuries, obesity (the less you sleep, the more you are likely to eat), problems with reproductive health, skin, immune system, and mental health troubles, and for men, lower levels of testosterone. The shorter you sleep, the shorter your life. Sleep is even more important to physical and mental health than diet and exercise. Aside from regulating physical health, sleep is natural soothing therapy, it improves memory and performance, and enhances emotional intelligence and creativity. Here is one personal takeaway — I have regularly deprived myself of sleep throughout the years and it seems to have had a major role in how I got type 1 diabetes at the age of 32 — I have not heard a better explanation. Here is another important lesson — it is impossible to “make up” for lost sleep. Or how about this — sleep deprivation is a form of torture — yet we do it to ourselves all the time.
2. Develop and maintain sleep habits — Stick to a sleep schedule, even during weekends. Keep your bedroom dark, cool and gadget-free. Don’t exercise too late in the day. No alcohol, nicotine, or caffeine before bed. Don’t get used to sleeping pills. Don’t do a pre-sleep nap on the couch. Avoid large meals before bed. Reduce liquid intake in the evening in order not to wake up in the middle of the night — this becomes more relevant as one ages. Don’t lie in bed awake. If you can’t sleep, get up, and do an activity to relax. Try to relax before bed — read or listen to music, or take a hot bath before bed. Also, be mindful of the effects of alcohol. Alcohol fragments sleep and makes it less restorative, depriving you of dream sleep.
3. Afternoon nap — Afternoon nap is natural and very useful. But remember, afternoon naps are not a tool to fix your night sleep troubles. Make sure you get a full night’s sleep first. The ideal afternoon nap is shorter than an hour and is around noon, before 2 or 3 p.m. Too long or too late (after 3 p.m.) a nap may mess with your night's sleep. Biphasic sleep (sleep with two phases) is, in fact, natural to humans. Biological, genetic, and anthropological evidence suggests that two bouts of sleep — one longer at night, followed by a shorter mid-afternoon nap — is the natural pattern to follow.
4. Wake up with sunlight. How do you know if you are getting enough sleep? If you wake up, but then can go back to sleep in a couple of hours, then you probably don’t get enough. Can you function without caffeine? If you cannot, your sleep cycle is off. Try not to use alarm clocks, but work to fix your sleep cycle. In fact, alarm clocks cause a spike in blood pressure and have a shock effect on your nervous system. Do not press the snooze button — why do it to yourself more than once? To realign your internal clock, try to follow Andrew Huberman’s advice — spend 5–10 minutes in sunlight right after waking up. This helps re-set your internal clocks and has a restorative effect on your sleep cycle.
5. If you have children. The book has a lot of good advice for parents. Put kids to sleep when they are drowsy. That way they are more likely to develop an independent ability to self-regulate sleep. Note that the circadian rhythms of younger children are earlier than adults. They go to sleep earlier and wake up earlier too. But for teenagers, the circadian rhythm of adolescent teenagers shifts forward (!), so they want to stay up later. This is not a sign of laziness or disrespect! Unfortunately, neither society nor the parents show awareness of this, that teenagers also need more sleep than adults, and that they are biologically wired to obtain that sleep at a different time than their parents. Walker goes on to recommend that delayed school start times increase class attendance, reduce behavioral and psychological problems, and decrease substance and alcohol use. Here is another incredible takeaway — it’s estimated that more than 50% of all children with an ADHD diagnosis actually have a sleep disorder.
6. Sleep is an insurance policy against injury. Getting adequate sleep on regular basis repairs and regenerates tissues after hard training. Sleep decreases the accumulated inflammation that training creates. The same goes for recovery from stress. When you sleep 6 hours or less, time to physical exhaustion drops by 40%. Less sleep decreases peak muscle strength, lung power, body’s ability to perspire and cool itself. Finally, injury risk increases exponentially with decreased sleep.
7. Chronotypes are real and owls (like me) suffer from chronic lack of sleep more. Whether you are a lark (who wakes up early) or an owl (who wakes up late) is determined by genetics. Owls have it rough since the general treatment of owls is that we are lazy and just need to be more disciplined. But it is in our DNA. Work or school schedules also do not factor this in and force owls into a problematic sleep-wake rhythm. Owls perform worse in the mornings and do much better in the late afternoon and early evening. Owls are also typically sleep-deprived since we mostly have to wake up early and then are most productive when larks are already asleep, thus causing health problems.

There you go. Incredibly, we are the only species on this planet that deliberately deprive ourselves of sleep. Remember — less sleep means weakness and disease. Abundant sleep means health.