Best not to sleep for eight hours

I usually sleep about six or so hours a night, and it’s usually broken sleep. Lying awake for an hour or more in the middle of the night is no fun, but I don’t worry about it. Sometimes it’s even productive. I plan menus or think up book ideas. Sleep experts agree that eight hours of sleep is not optimal. Rather, it’s 6.5 to 7.4 hours. A study of 1.1 million people concluded that those who reported more than eight hours of sleep “experience increased mortality rates.” Scientists who have studied hunter-gatherer tribes in Bolivia, whose lifestyles remain the same as our forebears of two million years ago, found that they average less than 6.5 hours of sleep a night.

Nevertheless, the idea that you need eight hours of sleep persists. In 2024 there were more than 2,500 sleep-disorder centers in the U.S. accredited by the American Academy of Sleep Medicine. Aric Prather, the director of the behavioral-sleep-medicine research program at UC San Francisco says the wait time at his clinic is one year. “We have people coming into our insomnia clinic saying ‘I’m not sleeping eight hours’ when they’re 70 years of age. And the average sleep in that population is less than seven hours.” Making matters worse, fear of losing sleep causes sleep loss.

Thomas Wehr, age 83, once the chief of clinical psychobiology at the National Institute of Mental Health, says that humans aren’t necessarily meant to sleep in one long stretch but rather in two shorter ones. The night awakenings tend to happen as we’re exiting a REM (rapid eye movement) cycle, when our dreams are most intense. He says, “If you know you’re going to fall back asleep, and if you just relax and maybe think about your dreams, that helps a lot.” When I’m awake in the middle of the night, I don’t think about my dreams. I can’t remember them.

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