Sleeping late on weekends will not protect you from the ravages of just sleeping during the work week, suggests a new study. Although extra nights of sleep temporarily helped volunteers eat lighter and better control their blood sugar levels, the health benefits disappeared as soon as they started sleeping again. In some respects, their situation was even worse than that of people who were still sleeping poorly.
Getting an extra hour off the weekend to pay off the accumulated sleep debt during the week has long been a strategy for any typical student or shift worker. But according to the authors of this study, published Thursday in Current Biology, there are surprisingly few studies on the effects of sleep on health.
The researchers, based at the University of Colorado, have therefore conducted a relatively simple experiment.
They recruited 36 healthy young volunteers, divided by sex, to stay in their sleep lab for two weeks. After taking three days to establish a typical sleep base, the volunteers were divided into three groups. One group was the control group, sleeping about eight to nine hours a night for nine days, while another group was allowed to sleep only five hours a night. The last group slept poorly during a 5-day workweek, then had the chance to sleep as long as he wanted on the weekend, then had to sleep again for two days.
As expected, compared to the control group, people with chronic disorders nibbled more after dinner and reduced sensitivity to insulin, a risk factor for metabolic diseases such as hyperglycemia, diabetes-type 2 and obesity. Over the weekend, the sleepers slept about an hour more per night (they slept more on Friday and Saturday, but did not go to sleep earlier on Sunday when they knew they would wake up early Monday). This extra sleep seemed to help them eat less after dinner on average.
Importantly, however, once this group returned to their short sleep schedule, their level of midnight snacking, weight gain, and reduced insulin sensitivity dropped in line with the chronic poor sleep group ; there were even signs that their health had deteriorated. After sleeping poorly again, for example, the circadian body clock of the weekend sleepers was delayed, while the insulin sensitivity of their muscles and liver was higher on average than that of the suffering group. chronic sleep.
Fortunately, exhausted volunteers from both groups had a few days after the experience to sleep very long. But it is unclear, given that volunteers only slept an extra hour on the weekend when they were free to sleep, how much sleep would help in the weekend to a person without sleep.
"The main message of this study is that recovery or restorative sleep after the weekend ad libitum does not seem to be an effective strategy for counteracting metabolic disturbances induced by sleep loss," said Kenneth Wright. a sleep scientist at the Center. University of Colorado at Boulder, said in a statement.
Although it is possible that people who sometimes only sleep late during the week can still get some sleep on weekends, this does not describe a substantial number of Americans. Other research has shown that one-third of American adults do not have the recommended amount of time to sleep seven hours a night – many of them are likely to catch up in their spare time. It is also the last study to establish a clear link between poor sleep and poor metabolism.
So yes, just some good news to chew while you leave for the weekend. Sleep well!