Why We Sleep

Matthew Walker's discussion on Peter Attia's podcast (The Drive, Episodes 47 - 49) is one of the most interesting things I've ever heard. At six hours long, I was sad when it ended and immediately wanted to listen to it again. If you've any interest in sleep, I highly recommend you check it out immediately.

I picked up this book after hearing that podcast, and the book just isn't on the same level as those interviews. It's an entirely serviceable piece of science communication, but that's about it.

The text is a high level synopsis of key pieces of research and related anecdotes. It's interesting enough, but it just isn't very engaging. Dr. Walker does go through practical recommendations on how to get better sleep, but the focus is really on explaining what sleep is and isn't.

If you don't know much about sleep, and are looking for an overview of the science, this is probably a really good place to start. But I would honestly recommend just listening to the aforementioned podcast and using the book to reference terminology later.

Like any 21st century pop science author, the premise of a long book about sleep couldn't be a down-to-earth argument of marginal health improvements. Instead, it doubles down multiple times on how this has to be, "undeniably", the most important yet neglected health knowledge ever - a common recipe for best sellers, promising immense rewards for memorizing a few key concepts.

Stripped down of the obvious marketing strategy, the over-the-top framing and all the speculative fluff mixed in with the actual research data, the book does a good work on hammering the need of caring for our sleep. And like any book of its kind, in the end the advice is as predictable and close to common knowledge as one would guess:

1) Go to bed and wake up at the same time every day; 2) Exercise at least 30 minutes, not too close to bed time; 3) Avoid caffeine and nicotine after noon; 4) Avoid alcohol before going to bed; 5) Avoid large portions before going to bed; 6) Avoid medicines that delay or disrupt sleep; 7) Don't take naps after 3PM; 8) Relax before bed; 9) Hot bath/shower before bed; 10) Dark & cool bedroom, no screen devices; 11) Get morning sunlight every day; 12) Don't lie in bed awake;

Most annoying of all, no concrete answers on "why we sleep". Walker presents some speculative argumentation regarding what fits an evolutionary and utilitarian viewpoint, but very little evidence is available anyway and, most worryingly, zero counter-evidence or opposing research viewpoints are discussed. In the end, the answer currently available is as obvious as the 12 advices above: because it's good for us.

There was quite some 'I didn't know that!' in the book. What NREM and REM sleep do. What the consequences of deprivation are - both minute seeming (6 instead of the 7 to 8). How the brain develops over time (frontal cortex last, babies, kids and adolescents have vastly different schedules because of the development).

And of the things I did know, I learned the the background. Alcohol is a very good REM sleep precentor (and hence best avoided.at all cost). You really really need to sleep in order to learn. There's also a lot of repair going on from the brain damage ordinary day to day use is doing.

I was actually shocked how little I knew. Because of this book I have drastically changed my sleeping habits.

The writer has gotten some flak on two things (a yet unsupported claim lack of sleep causes dementia and the mention of a study with a woefully inadequate sample size), but that didn't detract from the rest of the book which seems to have solid backing and/ or medical consensus.

If you don't want to read this book, at least read the twelve tips for healthy sleep the American NIH has issued.

It’s 1/3 of our lives. We get no formal education on sleep and this is a crash course. You'll view and prioritize sleep differently, improving the other 2/3 as well.

Cons: It's incredibly long winded and dry. For every interesting or relevant fact, there’s 8 pages of participant results in various sleep studies to back it up. Despite the author's best efforts to make it easy reading (historical anecdotes and examples in the media), it’s effective at inducing sleep. I’ve been chipping away at this for two months.

There’s a lot to learn here. The history of human and animal adaptation, brain activity during sleep, the benefits of 8hrs, the health risks of less than 8hrs, circadian rhythm change through life, dreams and memory, sleep disorders and drugs, effective nightly routines, and suggested changes to our culture are in here between a lot of tedious and scientific verbiage.

Until there’s a more succinct option, everyone should read this book.