The bad health effects of sleep loss during the week can't be repaid by longer weekend sleep, according to a new study.
Researchers have long known that sleep deprivation (剥夺) can cause weight gain and increase other health risks. But for those who force themselves out of bed every weekday after too few hours of shut-eye, they hope turning off the alarm on Saturday and Sunday will repay the weekly sleep debt and remove any ill effects.
The research, published in Current Biology, crushes those hopes. Despite complete freedom to sleep during a weekend recovery period, people in a sleep lab who were limited to five hours of sleep on weekdays gained nearly three pounds over two weeks and experienced disorders that would increase their risk for diabetes(糖尿病) over the long term. While weekend recovery sleep had some benefits after a single week of sleep loss, those gains were wiped out when people fell right back into their same sleep-deprived schedule the next Monday.
"If there are benefits of catch-up sleep, they're gone when you go back to your daily schedule. It's very short-lived," said Kenneth Wright, director of the sleep and chronobiology lab at the University of Colorado at Boulder. "These health effects are long-term. It's kind of like smoking once was—people would smoke and wouldn't see an immediate effect on their health, but people will say now that smoking is not a healthy lifestyle choice. I think sleep is in the early stage of where smoking used to be."
Wright said that the study suggests people should put sleep in the first place—cutting out the "sleep stealers" such as watching television shows or spending time on their phones. Even when people don't have a choice about losing sleep because of child-care responsibilities or job schedules, they should think about getting sleep in the same way they would get a healthy diet or exercise.
