Swedish scientists from the Karolinska Institute found that just two nights of insufficient sleep is enough to make a person feel 4.4 years older than his or her age. The study was published in the scientific journal magazine Proceedings of the Royal Society B (RSPB).
Experts conducted two experiments. In the first, 429 people ages 18 to 70 answered questions about how old they felt they were and how many nights (if any) they had slept badly in the past month. It turned out that volunteers felt an average of three months older for every night they slept less.
In the second study, researchers asked 186 volunteers ages 18 to 46 how old they felt after two nights of long sleep, in which they stayed in bed for nine hours each night and slept only four hours two nights. After two nights of limited sleep, participants felt an average of 4.4 years older than when they got adequate sleep.
The opposite effect was observed when people stayed in bed for nine hours. But here the effect was more modest: After a good rest, trial participants reported feeling an average of three months younger than their actual age.
According to scientists, in addition to feeling weaker, the perceived increase in age also affects people’s mood, making them less active, social and open to new information.
Previous scientists I learnedPeople who exercised at least a few hours a week were 42% less likely to have problems falling asleep.