Why We Sleep

Matthew Walker, Ph.D.

Audiobook length: 11m 46s

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Part of the Sleep Better Reading List

Sleep is one of the most important, but least understood aspects of life, health and longevity. Until recently, science had no answer to the question of why we sleep. Now, preeminent neuroscientist and sleep expert Matthew Walker provides a new understanding of the importance of sleep.

The Bottom Line

Scientists have found a treatment that can help you live longer, be more attractive, stay healthy and avoid feeling depressed, anxious or stressed. It’s called sleep.

I. Introduction

The title of Matthew Walker’s book is misleading, in that it suggests that we sleep for one reason. When in truth, sleep enhances our ability to learn, memorize and make logical decisions. It recalibrates our emotions, replenishes our immune system, fine-tunes our metabolism and regulates our appetite. The answer to why we sleep, then, is because nearly every biological function in the body depends on sleep.

And knowing that our well-being is contingent on regular and sufficient sleep, humans are the only species who regularly deprive themselves of sleep. The result is more than a passing concern, it’s a health crisis. In fact, the World Health Organization has declared sleep loss an epidemic in industrialized nations. Of the four main biological drives — eating, drinking, reproducing and sleeping — sleep, and why humans try to get by without it, is a puzzle that scientists have yet to solve.

Walker, director of UC Berkeley’s Sleep and Neuroimaging Lab, theorizes that people aren’t sleeping enough in part because doctors don’t adequately explain the importance of sleep. Granted, it’s not an easy subject, and our need for sleep is complex. But what’s perfectly clear, according to Walker, is that “sleep is the single most effective thing we can do to reset our brain and body health each day.”