"If somebody is routinely awake for more than 18 hours daily, then they are also routinely sleeping for less than six hours daily". But this study suggested that catching up on sleep over the weekend could alleviate that risk.
Fortunately, they found that if you're one of those people who struggles to get a full night's sleep, the damage can be reversed.
Don't sleep too much, however.
The study examined 38,000 adults and found there was a 65 percent higher mortality rate for people who got less than 5 hours of sleep during the week and continued that habit into the weekend.
Researchers examined data from almost 44,000 people who took part in a 1997 Swedish medical survey - and then tracked how many died within the next 13 years.
"The assumption in this is that weekend sleep is a catch-up sleep", said Åkerstedt, though he noted the study did not prove that to be the case.
Interestingly, study participants who consistently got more than eight hours of sleep a night were found to have a 25% higher mortality rate.
"Apparently, sleeping in in on the weekends can be a real help", said Åkerstedt, a professor and director of the Stress Research Institute at Stockholm University. For people who slept for less than five hours throughout the week but slept longer on the weekends for about nine hours, there was no increase in mortality risk.
While it will take more than one epidemiological study to prove anything definitively, the experts says the new paper is a step toward better sleep understanding. He thinks a lot of people may relate to sleeping less during the week and, at the very least, may want to have an excuse for sleeping in on our days off.
Average sleep duration at weekends and the percentage of those saying they did not feel rested at waking, did fall with age.
There were limitations to the study, such as the participants only being asked about their sleeping habits only once, making it impossible to detect changes in their sleep habits over time. Across the week, older people had more consistent and more often sleep over a shorter time span.
Despite those potential issues, "body clock" researcher Stuart Peterson told The Guardian that the study adds much needed context.
"Being an inactive "couch potato" is not good for you", Siegel said in an email to TIME.