Why We Sleep by Matthew Walker: A Review

It is a book that has been featured in different episodes of podcast I listen to. I have heard people talking about it just like last year when Sapiens became a must-buy book of every household. The fact that this book was mentioned in the context of enhancing productivity caught my attention. Without having to read it, you would probably get the idea straight away. The book will just tell you to sleep more. I was sleeping around 6 hours a day and I thought that was enough. It took me a while to get hold of the book and read it. After finishing it, I had no hesitation to recommend this book to you too, dear readers.

I would say the outstanding feature of this book that is worth commending is the scientific evidence that backs up the author’s claim/proposition. For me, the basic fact of life and the rule of thumb that I had stuck to before finishing the book was that it is good to get enough sleep. I vaguely knew that good sleep helps you function better the next day. Yet I did not know the extent of the profound effects of the difference between getting six and seven hours of sleep on our health and, as my podcast presenter correctly cited, our productivity.

“Routinely sleeping less than six or seven hours a night demolishes your immune system, more than doubling your risk of cancer. Insufficient sleep is a key lifestyle factor determining whether or not you will develop Alzheimer’s disease.” These two sentences basically sum up the extent of impact that sleep or indeed the lack of it has on our lives. These claims are not without back ups. Each chapter is filled with scientific evidence. Walker goes on a lengthy explanation of Non-rapid Eye Movement (NREM) and Rapid Eye Movement (REM) sleep patterns to come to a conclusion that our cognitive abilities as well as how well we control our emotions are rooted in how much we have been getting NREM and REM sleeps. The fact that both types of sleep occur in unequal intervals throughout the night means that waking up super early (at 4 or 5 am) may deprive you of motor-skill enhancement caused by NREM sleep that is concentrated in the later hours of sleep.

The second feature is that the outcome of researches in the book is new and fresh. You may argue that there are tons of books on sleep in the market. However, Walker has done quite a wide range of researches on sleep. Many of which have been revealed and explained for the first time in this book. I personally found the experiments relating to memory fascinating. While I cannot remember exactly how it was done since there were a few similar experiments conducted (and perhaps I did not get the needed sleep last night!), the conclusion was that after learning new things and not getting good sleep that night, you won’t be able to remember the things you learned very well. That sounds normal. But it was found that several recovery sleeps after that did not help at all. This means if you fail to sleep well on the day you learn something new, you will have a good chance of not being able to learn it well at all.

The third reason why I would recommend this book to anyone is that it is immensely relatable. The book is filled with anecdotes of urban myths that we all know (and believe in) too well. Each of those myths is deconstructed and debunked by data yet some myths have also been confirmed again with scientific evidence. One example is that there are people who tend to wake up early but there are also some people who have been engineered from birth to go to bed and wake up a bit later. The book does not intend to answer all questions relating to sleep. Walker admits that the science of sleep is a large sphere and there are researches and experiments going on as we speak. Yet the book has made good grounds in this field and has, through Walker’s skillful writing, invited others to spend some of their resources researching about sleep.

While Walker encourages readers to read his book before sleep, my experience does not suggest you doing so, in particular when reaching chapters on effects of the lack of sleep on health. Throughout the two-week period that I spent reading this book, I suffered from the inability to go to sleep for many days. I would suggest you read it during the day. Or if you cannot help it, early in the night.