Strong Sleep

Sleep Duration Recommendations

Summary

Most adults need somewhere in the **7-9 hour** range of *actual* sleep, the floor (≈7h) is better established than the ceiling, both ends of the famous U-shaped mortality curve are real in the data but the *long*-sleep end is largely poor health showing up as a symptom rather than long sleep causing death — and while a real "natural short sleeper" gene exists, it is so rare (on the order of dozens of confirmed families worldwide) that if you are reading this and feel fine on five hours, the overwhelmingly likely explanation is that you are sleep-deprived and have stopped noticing. ---

HIGH that 7-9h is the right default and that habitual short sleep is harmful for almost everyone; MODERATE on the precise shape of the duration↔mortality curve (measurement-fragile, confounded); LOW/EMERGING on whether *long* sleep itself causes harm vs marks pre-existing illness; HIGH that natural short sleepers are too rare to be your working assumption.Last updated June 2026
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