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Caffeine decreases sleep duration?
How long before bed should caffeine be avoided?
The stimulant caffeine has shown to increase exercise performance. Therefore, caffeine is widely used by different types of athletes. However, can it affect sleep duration and quality?
This study investigated the effect of 400 mg of caffeine (~2 large coffees) on sleep when taken 0, 3, or 6 hours before going to bed. Sleep (at home) was investigated with sleep diaries and a validated sleep monitor.
As expected, caffeine right before sleep (0 h) decreased sleep duration by an hour. However, even when caffeine was taken 3 or 6 hours before bed, sleep duration was decreased by an hour.
The shorter sleep duration was explained by a longer time until subjects fell asleep, and by more wake times (short wake periods) during the night.
In conclusion, caffeine disrupts sleep even when taken 6 hours before bedtime. Therefore, it is advised to limit caffeine intake during the late afternoon and evening.
Go to the next infographic in the sleep series:
Caffeine can’t counteract long-term sleep loss?