If you thought sleeping in at the weekend makes up for a week’s worth of sleep deprivation, you thought wrong. A study has proven what we all kind of knew but didn’t want to accept: weekend lie-ins don’t balance out a week of rubbish sleep.
In fact, trying to play catch-up for a few days and then returning to poor sleep habits can make things worse for some parts of your health, the study found.
“The common behaviour of burning the candle during the week and trying to make up for it on the weekend is not an effective health strategy,” said senior author Kenneth Wright, from University of Colorado Boulder.
Researchers at the University of Colorado Boulder enlisted 36 healthy adults, aged 18 to 39, to stay for two weeks in a laboratory, where their food intake, light exposure and sleep were monitored.
The volunteers were divided into three groups. One was allowed plenty of time to sleep – nine hours each night for nine nights. The second was allowed five hours per night over that same period, and the third group slept no more than five hours per night for five days, followed by a weekend where they could sleep as much as they liked (called “the recovery group”).
Both sleep-restricted groups snacked more at night, echoing previous research that lack of sleep can raise the risk of obesity. People in these groups gained weight and saw declines in insulin sensitivity during the study period. Low insulin sensitivity, or insulin resistance, is associated with type 2 diabetes, but can also occur amongst type 1 diabetics as well, according to Diabetes UK.
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Those in the weekend recovery group saw mild improvements during the weekend (including reduced night-time snacking), but those benefits went out of the window when the sleep-restricted work week resumed. “In the end, we didn’t see any benefit in any metabolic outcome (processes that occur in the body once food is eaten) in the people who got to sleep in on the weekend,” said lead author Chris Depner.
And in some ways, the weekend recovery group showed worse outcomes. In the group which had its sleep fully restricted, whole body insulin sensitivity declined by 13%. In the weekend recovery group, it worsened by 9 to 27%, with sensitivity in the muscles and liver scoring worse than the other groups.
“It could be that the yo-yoing back and forth – changing the time we eat, changing our circadian clock and then going back to insufficient sleep is uniquely disruptive,” said Wright.
Even when given the chance, people found it difficult to recover lost sleep. While they gained some ground on Friday and Saturday, their body clocks shifted later on Sunday night, making it hard to fall asleep despite the early Monday morning alarm.
On average, the recovery group got just 66 minutes more sleep and men made up more lost sleep than women.
Wright said it’s possible that weekend recovery sleep could be an effective health countermeasure for people who get too little sleep a night or two per week – and researchers hope to explore this in future studies.
But for now, the takeaway is this: consistency matters. Trying to get seven to eight hours of sleep for as many nights as possible is best. As for the weekend mornings, maybe it is about getting up early and seizing the day after all...