How much sleep do I need? Why you can forget the eight-hour rule
The eight-hour figure traces back to the mid-19th-century split of the day into eight hours of work, eight of recreation and eight of sleep, not to sleep science. Studies of hunter-gatherer communities with little or no artificial light found people sleeping between 5.7 and 7.1 hours a night, waking close to dawn without alarms and showing no need for long daytime naps. A new narrative review argues the right amount of sleep depends on your age, your body clock and your individual needs. Even in pre-industrial societies, measured sleep varies with the season, the setting and the method used to record it.
For you: If you feel rested on less than eight hours, there is no biological law saying you are failing; the eight-hour figure is a convention, not a prescription.
What it shows: Reported by The Conversation (UK health) and not verified by us: we could not trace this story to a published paper, so treat it as news rather than evidence we have checked.