Why We Sleep
Written by Matthew Walker, PhD.
⏱️ The book in three sentences
The effect of a full night's sleep on health and performance is foundational and non-negotiable.
Sleep is the most underrated and undervalued aspect of our lives in the modern world.
If we, as a community, learned to respect sleep to the extent it deserves, we would all be better off.
🪞 Reflections
If you are in the habit of neglecting sleep; treating it as an annoyance, rather than a catalyst for high performance, this book will be a difficult read. Not because of an inability to focus optimally (a very likely scenario), but because of how fundamental the book's author, Matthew Walker, reveals sleep to be.
Walker, a scientist and professor at the University of California, Berkley, has studied sleep for over twenty years. Why We Sleep: The New Science of Sleep and Dreams, therefore, is his magnum corpus - not of just his own research though, it's everything he knows and has learned throughout his career.
Backed up by clinically controlled, peer-reviewed studies, the book covers every question you've ever wondered about sleep and more.
What actually is sleep? Why do we need it? Do older people need to sleep less? What is the effect of jetlag on our health? What happens when we neglect sleep in the short term? What about in the long term? Why do we dream?
It's all explained confidently and meticulously, crescendoing into the final stretch of the book where Walker breaks down just how wrong our society has judged sleep. Good health is not built on the three pillars of food, exercise and sleep, he explains. Good health is built on the two pillars of food and exercise, and those are built on the foundation of sleep.
Every single living creature on earth, from whales whose brains sleep one-half at a time in order to continue swimming, to single-celled organisms like bacteria, take part in some form of sleep. Evolution, over four billion years, has found it either necessary to maintain the habit of sleep through countless generations and iterations of genetic code or has found it necessary to develop the activity across multiple independent points in time and species. The benefits of sleep are that important. Yet we have labelled it as lazy, unproductive and something to be negotiated on with our bodies.
LED screens, factory whistles and alarm clocks, sleep aids and nightcaps, and early school start times with even earlier bus schedules are wreaking havoc on our brains, hearts and nervous systems. Walker pleads us to stop. He gives suggestions on how we can make improvements at all levels of society, from governmental, to organizational, to individual. We are capable of turning this around and reaping the rewards nature offers with a full night of rest.
The solutions offered by Walker are not unrealistic either. He does not suggest abandoning modernity, but rather embracing the luxuries offered by technology to redesign sleep's role in the developed world. Many of us wear fitness trackers, he points out, and the capability of these devices to reliably track sleep is only getting better. As the internet-of-things sneaks its way into our daily lives, we can combine these two forces, customizing sleep for every individual. Perhaps your device will learn your specific, genetically determined sleep cycle. If it is connected to the lights in your home, automatically, your house could begin to filter out blue light as bedtime approaches. Alternatively, blue light could be intensely broadcasted throughout the home in the morning. You would wake up quicker and your dependance on caffeine may be reduced. The applications of this idea reach further though. The blue-light technique could be used in cars as well, reducing fatigue and lowering the colossal death toll that drowsy driving accounts for.
The possibilities are endless, we just have to wake up and see them.
This book was an absolutely fantastic read. The quality of information more than makes up for Walker's often overly academic writing (no one needs to casually refer to skin as epidermis). If you care about your health, maybe you love to exercise or you're meticulous with your nutrition, you have to read this book. You are likely missing out on one of, if not the biggest, determinants of good health - and the sooner you learn about it, the better.
💥 Personal impact
I am no stranger to neglecting sleep. Although I often fail at late-night productivity due to a frustrating inability to keep my eyes open past 10 pm. Morning alarms, however, have been a part of my daily life for a long time. Even on weekends, it's common to find me up before 6 am to watch an early morning soccer game. What I didn't realize, though, was just how damaging this has been to my body. For a guy whose only once taken more than two weeks off from the gym in four years, and who consistently racks up streaks of over 200 days in Myfitnesspal, Why We Sleep was a bit hair-raising but also relieving.
The scariness of sleep neglect is probably obvious at this point, but the book gave me relief because I've often felt deeply at odds with my body on the subject of tiredness. I try so hard to take good care of my body, yet I would often struggle to keep my eyes open in the mid-afternoon. At some points, four or five coffees a day was not an infrequent occurrence.
Nonetheless, this May, after finishing school and transitioning to a full-time work-from-home job, I decided to take part in my own self-directed experiment. I would still go to bed at my usual bedtime of around 9-10 pm, but no longer would I set an alarm. Period.
I should preface this by saying that I am usually incapable of waking up after 8:00 am. I wasn't worried about being late for work. I just wanted to see what a prolonged string of natural wake-ups would do to my energy levels. The results were game-changing.
My horrendous mid-afternoon slumps recovered into little more than a dip (something that's completely natural, as Walker points out). But, my overall energy levels also went through the roof. I was more motivated in both work and the gym, with performance and productivity reflecting that.
The change, ultimately, was what led me to read this book. I was sold on the importance of sleep. Why We Sleep, therefore, has only emboldened me further.
You know those people that drive you crazy talking about their new, all organic, carb-based, juice cleansing, baby food diets? Well, I'm probably going to be like that for sleep. Hopefully, my friends and family can forgive me.
As of today, September 16th, 2021, the time of writing, I'm down to one cup of coffee in the morning and I'm working on cutting that back too. I am setting an alarm again, just in case, but for a much later time and I usually wake up naturally long before it. Actually, on average, I'm probably waking up earlier than I was before.
So, next week I'm going to deviate from the book review thing and tackle some of the misconceptions most of us have about sleep and offer some solutions for getting better rest at night. Hopefully, you find it helpful.
🗣 Top three quotes
We no longer have to ask what sleep is good for. Instead, we are now forced to wonder whether there are any biological functions that do not benefit from a good night’s sleep. So far, the results of thousands of studies insist that no, there aren’t.
How do you know whether you’re routinely getting enough sleep? ...First, after waking up in the morning, could you fall back asleep at ten or eleven a.m.? If the answer is “yes,” you are likely not getting sufficient sleep quantity and/or quality. Second, can you function optimally without caffeine before noon?
After ten days of just seven hours of sleep, the brain is as dysfunctional as it would be after going without sleep for twenty-four hours. Three full nights of recovery sleep (i.e., more nights than a weekend) are insufficient to restore performance back to normal levels after a week of short sleeping.