With so much to do, and so little time to accomplish it, sleep can feel like a waste of a precious resource. Wouldn't it be great if we could train our bodies to need less sleep?
It is possible, some research has found. But it won't work for everyone.
“There are far more people who would like to need less sleep than who actually need less sleep,” says Dr. Daniel Buysse, professor of psychiatry at the University of Pittsburgh and a past president of the American Academy of Sleep Medicine. Though the amount of sleep a person needs each night depends on their age and physical activity, most healthy adults should get between seven and nine hours each night. Many don't hit that target: about one third of Americans get less than seven hours of sleep a night, according to the Centers for Disease Control and Prevention.
Sleep is vital for the brain and the body to function at their best, and when a person doesn’t get enough of it, their brain can’t repair or build new pathways, Buysse says. That makes it more difficult to retain information, engage in complex thinking and stay focused. Sleep deficiency has also been linked to physical health problems, such as obesity, high blood pressure and heart disease.
When you slash your sleep hours, your body notices—even if you don't. In one famous sleep study, people cut down their sleep to just six hours a night. Their cognitive performance and reaction times dropped as much as they did in people who went two full nights without sleep, and their bodies didn't adapt to the new sleep schedule, even though the short sleepers were mostly unaware of their poor performance.
“In some ways, sleep deprivation is like intoxication with alcohol,” Buysse says. “People routinely misjudge how impaired they are, and it’s been shown the same thing happens with insufficient sleep.”
Still, it may be possible to teach yourself to get by on sleep less, according to Jim Horne, a sleep expert and former director of the Sleep Research Centre at Loughborough University in England. He argues the number of hours people need to sleep is more flexible from person to person and that concerns about not getting your nightly seven or eight hours are often overblown.
“I’m not advocating people get less sleep, but I’m advocating that people should not worry so much about not getting enough sleep,” Horne said. “Especially if you’re not sleepy in the day and you’re having a fulfilling wakefulness, then you are getting enough sleep irrespective of how much you’re getting.”
Horne’s research shows that people can cut down their regular sleep to about six hours a night, plus a short nap during the day, as long as they do it gradually. In one study, he asked people who regularly slept seven to 8.5 hours a night to shorten their sleep by going to bed a certain amount of time later each night. Volunteers started by pushing back their bedtime one hour during the first week, and then pushed it back by 1.5 hours for the next three weeks. After doing this and waking up at the same time each morning, people were able to successfully function—and get high-quality sleep—on just six to 6.5 hours of sleep each night.
Gradually going to bed later might work well for some, but Horne says he wouldn't recommend it for people who already feel like their sleep time is constricted. If you feel sleepy during the day, Horne said, then six hours is probably not enough for you. Instead, he says, focus on getting quality sleep rather than worrying about the quantity.
Making better use of your waking hours is another way to thrive on less sleep. Try exercising in the afternoon, says Sigrid Veasey, a professor at the Center for Sleep and Circadian Neurobiology at the University of Pennsylvania’s Perelman School of Medicine. This will raise your body temperature and then cool it down by bed time, helping you fall asleep more quickly and sleep more deeply through the night. Other tips for optimizing your sleep include avoiding a large meal late in the evening, making time to think about worries before bed so you don’t go to sleep stressed, avoiding looking at screens right before you sleep and making sure the bedroom is dark and quiet.
These are good places to start if you want to make the most of the sleep you get. But if you're still feeling sluggish, only more sleep will help.