Want to live to 100? Well, then get 10 hours of sleep a night, suggests a new study.
Sleep is a major factor in rejuvenating the body and activating the immune system.
In the study, boffins found that people who reach 100 are three times more likely to spend at least 10 hours a night in bed.
The study involved analysis of data from a 2005 Chinese survey. The sample was composed of 15,638 adults aged 65 and older, including 3,927 who were between 90 and 99 and 2,794 who were 100 or older, reports The Daily Express.
Dr Danan Gu, of Portland State University in Oregon, said: "About 65 per cent of the sample overall reported that their sleep quality was good or very good, and the weighted average daily sleep time was about seven-and- a-half hours including naps.
"Surprisingly, the oldest adults aged 100 and above were 70 per cent more likely to report good sleep quality than younger participants aged 65 to 79.
"Participants who were 100 years of age and older were less likely to sleep for five or fewer hours a day but they were almost three times more likely to sleep for 10 hours or more.
"Men were 23 per cent more likely than women to report sleeping well."
When humans sleep, their cells regenerate and they also remove toxins and activate immune system cells.
The research has been published in the May issue of the journal Sleep.