I’ve been benefiting from this book’s comprehensive view of rest. As the subtitle says, “Why sleep alone is not enough.” But it is an important foundation, as Edlund outlines in chapter 1. Here’s a summary:
1. Sleep Is Necessary for Weight Control.
From 2003 to 2009, multiple population studies around the world have shown that people who sleep fewer than seven hours, especially those getting fewer than six hours of sleep, gain appreciable weight. In the small-scale, short-term studies done in 2008, sleeping an extra 30 to 60 minutes a night decreased weight. Some people rapidly shed 10 to 15 pounds.
2. Sleep Is Required for Memory and Learning.
The better you sleep, the more you learn. The deeper the sleep, the better our learning. But research at Harvard has shown that short periods of daytime sleep—even as short as a six-minute nap—can improve memory.
3. Sleep Is Needed to Prevent Major Clinical Depression.
When people sleep enough, their mood quickly improves. And getting enough sleep should also go a long way toward preventing major clinical depression, an illness whose rates have been doubling and tripling among Americans over the last 30 years.
4. Sleep Is Required to Grow New Brain Cells.
This has only been discovered in the past few years, overthrowing years of scientific dogma.
5. Sleep Is Needed to Avoid Colds and Fight Off Infection.
Rest is more than restoration. Rest is on the front lines of your infection defense system. It keeps your immune system going. Rest prevents infection. Rest well, stay well.
6. Enough Sleep Prevents Plaque From Forming in Your Arteries, Preventing Heart Attack and Stroke.
Arterial plaque is the basis of the majority of heart attacks and strokes, and fortunately for us, good sleep can prevent its even getting started.
7. Proper Sleep Is Required to Maintain and Strengthen the Inner Clocks That Regulate Our Lives.
It doesn’t really matter when you sleep; what does matter is the regularity of your pattern, when you wake and when you sleep. Your clocks are regular in their timing for a reason. Life is rhythmic. So is sleep. To know when to sleep, it pays to know a little about your own inner music.