Why we Sleep by Matthew Walker PhD - Book Summary

I have been a very sound sleeper. However, for the past few months, and for no apparent reasons, my sleep has been rather erratic.

So, when I heard that there is this book which also happens to be a favorite of Bill Gates, I was inclined to read the book myself. And boy did it leave me scared!

First revelation from the book, was that I have been missing on at least one of the 3 important sleep cycles.

1. Deep Sleep - This one helps with reinforcing learning and usually happens in the first 90 minutes of your sleep

2. Light Sleep - Helps clean up hippocampus (you can compare this to RAM) and makes room for newer experiences and learnings

3. REM Sleep - AKA Rapid Eye Movement Sleep - where all the conscious and subconscious thoughts, memories and experiences come together in a rather serendipitous manner, giving rise to creations that perhaps were so far unknown to mankind. Eg. Paul McCartney came up with the entire composition of 'Yesterday' during a good night's sleep.

These cycles alternate and usually each cycle lasts for about 90 min. Skipping any of these cycles, such as by staying up late or waking up will mean we are not getting the full benefits of sleep. For me, this meant that when I thought I was living a healthy life, there is a lot of room for improvement.

The second revelation, and this was the scary part; There is a high price to be paid for missing a good 7-9 hours of sleep. [When you go to bed doesn't matter, how much you sleep does]

1. One study among Japanese executives who were observed for 14 years, found that individuals who slept less than 6 hours were 500% more susceptible to cardiac arrests compared to those who slept more.

2. Disrupted sleep especially among those who are in their 50s and 60s is a good predictor of early onset of Alzheimer's disease among those individuals.

3. Routinely sleeping less than six or seven hours doubles our risk of cancer, and destroys our immunity [A lot more of this is required especially now]

4. Many, many more ill-effects to list down here.

In Mathew's words human beings are the only species who have been voluntarily compromising on sleep-time. But now that we know it's ill-effects, it's clear we need to put sleep back on top of our priority. But how? Here are 4 Don'ts and 4 Do's.

Don'ts

1. Stop caffeine intake at least 8 hours before sleep time.

2. Stop using electronic devices at least an hour before sleep time. This helps with keeping the sleep-inducing hormone, Melatonin's levels up.

3. Avoid late afternoon naps.

4. Say no to sleeping pills and alcohol - they are sedatives which disrupt natural sleep.

On a side note, the author says there is no good time for a drink if you want to have a good night's sleep. But if you enjoy getting a little tipsy, early in the morning is much better ;). This way the alcohol's effects wane before you are ready for your sleep in the night.

Do's

1. Set an alarm FOR going to bed. Same time every night. Matthew says that if there can be only one take away from the book, let it be this.

2. Take a hot shower before you sleep. This sounds counter-intuitive but brings down the body's core temperature which helps with better sleep.

3. Keep your room dark (curtains) and cool (around 18 degree Celsius)

4. Leave the room, if you are not able to sleep, and go do something else until you are tired enough to come back. This way you will associate your bed with only sleeping.

'I will sleep when I am dead'. Two famous personalities, Margaret Thatcher and Ronald Reagan lived by this maxim, but both went on to develop the ruthless disease of Alzheimer's. It is time to feel proud and satisfied to have slept more than less.

Matthew started with 'Sleep', as the research topic for his PhD, and thought he will get answers to his questions in 2 years. His quest lasted for more than 20 years. This book is a result of all those years' efforts. And every chapter is filled with research anecdotes and rich insights making this a credible read. I highly recommend reading this book.

And if you got drowsy part way through this article, I ain't complaining.

Have a good night!