A recent article in Journal of the American Heart Association performed a meta-analysis following more than three million people and found those who slept nine hours a day died earlier than those who slept eight.

So does sleep need to be inside a “window” of seven to eight hours to obtain the best results?  Or is long sleeping a marker for something else?

Keep people up all night and they’ll sleep more the next day.  Fly from Beijing to Cincinnati and the discombobulation of jet lag plus the viral Superbowl of jet travel may occasion several days of prolonged slumber.  Get a bad cold and you might sleep “all day.”

The body sleeps to recover and rebuild. Illness often provokes more sleep.