Studies show that people who sleep between 6.5 hr. and 7.5 hr. a night, as they report, live the longest.
Sleeping 8.5 hr. might really be a little worse than sleeping 5 hr.
There have been many controlled studies in the U.S., Great Britain and other parts of Europe that show that an insomnia treatment that involves getting out of bed when you're not sleepy and restricting your time in bed actually helps people to sleep more