Did you get eight hours of sleep last night? Going by an informal poll I conducted last week, almost no one at Pacific Standard ever gets that much snooze time on weeknights. And our staff is not alone: According to more formal Gallup polls, Americans are getting less sleep than we used to, and that's a problem because insufficient sleep can be a significant public-health issue. Sleepiness itself can be hazardous—consider the potential consequences of falling asleep at the wheel—and sleep deprivation has been linked to an increased risk of diseases like diabetes.
The good news for us, and anyone else who skimps on sleep during the work week, is that a small study suggests catching up on sleep on the weekends may be enough to undo some of the damage of the sleepless weekdays.
"Sleeping in on the weekends really could be a way to protect your health."
In the new study, published today in Diabetes Care, a group of 19 young, healthy men participated in two phases of study: In one, the group was allowed 8.5 hours in bed for four nights in a row; in the other, the group was only allowed 4.5 hours in bed. After four days of sleep restriction, the group was given two nights of "recovery sleep," with 10 to 12 glorious hours to snooze. The researchers measured the men's insulin sensitivity, insulin response to glucose, and disposition index—a measure used to predict diabetes risk—after four nights of regular sleep, sleep restriction, and recovery sleep.
As expected, the team found that sleep restriction reduced the group's insulin sensitivity and increased their risk of diabetes. But the study also revealed that just two days of catch-up sleep were enough to bring their sensitivity and risk levels back to baseline.
The authors caution that the results may not be generalizable to a larger population. "Everyone thinks back to their college days of pulling all-nighters and partying, yet somehow keeping it together," says Josiane Broussard, an assistant research professor at University of Colorado–Boulder and lead author on the study. "These are young, healthy people, so just two nights of sleep may not be enough for older people or someone already on the path to diabetes."
The researchers also only conducted the sleep deprivation and recovery cycle once, and, according to Broussard, the effects of chronic sleep deprivation—week after week of missing out on sleep—might be harder to reverse.
Still, Broussard is optimistic about the findings. "The most important thing is for people to allow themselves to sleep in on the weekends, knowing that it really could be a way to protect your health," says Broussard, a sleep lover apparently after my own heart. "If I get less than eight hours I might as well call in sick to work."
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