03/11/2026
Six hours a night can feel normal while your attention keeps slipping.
In a sleep lab study, healthy adults were randomly given 4, 6 or 8 hours in bed a night for two weeks. On six or four hours, their scores on every thinking test got worse night after night.
How sleepy they felt rose over the first few days and then barely changed. The researchers said the volunteers were largely unaware of how much their thinking had slipped. Four hours did more harm than six and both groups rated their sleepiness about the same.
So if six hours feels fine to you, that feeling may not be the best guide. Start by protecting eight hours in bed for one week. As the saying goes, you can’t manage what you don’t measure.
How many hours in bed did you give yourself last night? Tell me in the comments.
Source: Van Dongen et al., Sleep, 2003
