Longer sleep on the weekends may lead to decreased mortality risk, according to a study published in Journal of Sleep Research conducted by Swedish and American researchers.
Monitoring the sleep patterns of nearly 44,000 subjects over the course of 13 years, study leaders discovered that people over the age of 65 that got less than five hours of sleep on the weekends had an increased risk of death. Subjects who got less than five hours of sleep on the weekends had "a 52% higher mortality rate...compared with the reference group (7 hr)."
The study indicated that those under 65 who regularly got more than nine hours of sleep had a 25 percent higher risk of mortality than people who got six to eight. Conversely, subjects under 65 who got less than five hours of sleep each night during the week had a 65 percent higher mortality rate than those who got more. The study included factors such as gender, body mass index, smoking, physical activity and occupation.
The study also found that sleeping for six to seven hours per night had a lower mortality rate than sporadic sleeping patters, such as sleeping fewer than five and more than eight hours on alternating nights. Getting longer sleep on the weekends, however, "may compensate for short weekday sleep."
"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," the study authors wrote. "This suggests that short weekday sleep may be compensated for during the weekend, and that this has implications for mortality."
Lead author and clinical neuroscience professor at Sweden's Karolinska Institute Torbjörn Åkersted noted that past studies were only focused on weekday sleep. Suspecting that weekday sleep "may not be enough," Akersted and his team concluded that making up for sleep debt on the weekends could mitigate previously associated risk of death from inadequate sleep. "I suspected there might be some modification if you included also weekend sleep, or day-off sleep," he said.
There are a few caveats to the study, though. Participants were only asked to document their sleeping habits once, rather than periodically. The study began in 1997, and participants were asked to fill out a lifestyle and medical survey.
"We would have had stronger results if we had collected sleep duration reports every 5 years, for example," Akersted explained. "People change their sleep duration over time. Thus, our results may contain an underestimation of risk." Akersted also said that his study's results were consistent with previous research into the links between sleep and mortality.
But people over the age of 65 may have the least to worry about because they typically get a sufficient amount of sleep, according to Akersted. "They sleep as much during weekdays as during weekends whereas the difference is huge in lower age groups," he explained. "We also note that the the older participants are 'well rested' when they wake up, whereas the younger are definitely not 'well rested.' Our interpretation is that sleep need is reduced with increasing age."
Hear that, young people? Get more sleep on the weekends, you'll live longer!
