Too Much Sleep

An interesting sleep study addressing that age-old question:

[Daniel Kripke] compared death rates among more than 1 million American adults who, as part of a study on cancer prevention, reported their average nightly amount of sleep.  To many his results were surprising, but they’ve since been corroborated by similar studies in Europe and East Asia.  Kripke explains. [...]

Studies show that people who sleep between 6.5 hours and 7.5 hours a night, as they report, live the longest.  And people who sleep 8 hours or more, or less than 6.5 hours, they don’t live quite as long.  There is just as much risk associated with sleeping too long as with sleeping too short. [...]

Morbidity, [or sickness,] is also "U-shaped," in the sense that both very short sleep and very long sleep are associated with many illnesses - with depression, with obesity, and therefore with heart disease and so forth. [...]

One of the reasons I like to publicize these facts is that I think we can prevent a lot of insomnia and distress just by telling people that short sleep is OK.  We’ve all been told you ought to sleep eight hours, but there was never any evidence.  A very common problem we see at sleep clinics is people who spend too long in bed.

It’s always sort of bugged me that I tend to wake up after 7 or 7.5 hours of sleep.  I sometimes go back to sleep and sleep longer than 8 hours, but I never sleep just 8.  But I guess it’s no problem after all.