As a night owl, I know what it’s like to struggle with the strict schedules society has set for us. Getting to bed to ensure eight hours of sleep is a daily battle, but it’s nothing compared with getting up in the morning to make it to work on time.
Throughout the week it can feel as though my body hasn’t rested enough because I often fail to fall asleep until very late. So I take the opportunity at weekends to catch up on my shut-eye — I rarely set an alarm and tend to wake up when my body wants to.
Sleep scientists have long been critical of my method. One of them, Matthew Walker, said last year: “Sleep is not like the bank. You can’t accumulate a debt and pay it off at a later point in time.”
But according to a study published on Tuesday in the Journal of Sleep Research, the effects of insufficient sleep over the week could actually be countered by a later lie-in at the weekend.
Sleep researchers from the Stress Research Institute at Stockholm University looked at data from more than 43,000 adults collected in Sweden in 1997. They then checked the national death register to see what happened to participants over 13 years.
They found that adults under age 65 who got only five hours of sleep or less a night, for seven days a week, had a higher risk of early death than those who consistently got six or seven hours. But those who made up for it at the weekend by sleeping in had no raised mortality risk compared with the steady sleepers.
“The results imply that short (weekday) sleep is not a risk factor for mortality if it is combined with a medium or long weekend sleep,” said the researchers, led by Torbjorn Akerstedt. “This suggests that short weekday sleep may be compensated for during the weekend, and that this has implications for mortality.”
Overall, Akerstedt suggested that it was a person’s average amount of sleep that seemed to make a difference and that the new study adds to the growing body of research that highlights this.
However, in the sleep-science community, the overarching advice is that consistency is key and that there is no substitute for having a regular sleep pattern.
In a previous interview with Business Insider, Elise Facer-Childs, a research fellow at the University of Birmingham, said that the more regular your sleep, the better. Otherwise, you can experience something called “social jet lag,” the misalignment between social and biological time. (Essentially, our bodies have clocks, called circadian rhythms — and if we mess with them, it can cause problems.)
“I would say that it is all about getting the right balance,” Facer-Childs said in a recent email. “Yes, if you are extremely sleep-deprived during the week, then continuing that over the weekend isn’t ideal, and maybe you should think about getting a few more hours.”
She added that the most important thing is the timing of sleep. For example, getting up at 6 a.m. for work during the week but sleeping until 10 a.m. at the weekend — a four-hour difference — can make your body feel as if you’re flying to Dubai every weekend then coming back on Sunday. You’re basically jet-lagged.
“If you’re sleep-deprived, it is probably better to try and fall asleep earlier than get up later,” she said, adding: “Although our social commitments at the weekend tend to prevent us from doing this.”
Not getting enough sleep has been linked to an increased risk of obesity and heart disease, as well as brain diseases like Alzheimer’s. There’s also evidence that sleep deprivation can contribute to a lower sex drive, reduced fertility, and generally poorer mental well-being.
So forget “sleep when you’re dead” — it might be more like “don’t sleep, and you will be dead.”
Originally published on www.businessinsider.com.
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