A study was carried out between 1995 and 1999 at the University of California, San Diego which aimed to find a link between sleep duration and mortality.
The study was led by Professor Daniel Kripke, who reviewed 459 women aged between 50 and 81. Then again the team is said to have revisited the research which now involved 444 women as the other 86 had already died.
“Women who slept less than five hours a night or more than 6.5 hours were less likely to be alive at the 14-year follow-up”, Kripke concluded.
The follow up hence made it very clear that women who slept 5 to 6.5 hours were among the best survivors. It has also been made clear that while five hours of sleep a night is too less to ask for, eight hours of the same can be harmful.
The study which had been carried out 14 years ago was based on questionnaires of sleep habits of people. The sleep durations at that time had been calculated with the help of wrist activity monitors.
Hence, for all the women who sleep five to six-and-a-half hours every day can live a wonderful life with excellent survival. This amount of sleep is believed to be the average sleep duration, which had been measured for all the women in San Diego.