The effect of caffeine on subsequent sleep: A systematic review and meta-analysis

This systematic review and meta-analysis examined caffeine's effects on sleep, analyzing data from 24 studies. Caffeine consumption reduced total sleep time by 45 minutes, delayed falling asleep by 9 minutes, and increased time awake after sleep onset by 12 minutes. It also reduced deep sleep stages (N3 and N4) while increasing light sleep (N1). The timing and dosage of caffeine were significant factors: coffee should be consumed at least 8.8 hours before bed and pre-workout supplements at least 13.2 hours prior. These disruptions to sleep can impair memory, emotional regulation, and cognitive recovery, emphasizing the importance of managing caffeine intake.

To optimize sleep and cognitive recovery, avoid consuming caffeine in the late afternoon or evening. Specifically, stop coffee intake at least 9 hours before bedtime and pre-workout supplements 13 hours prior. This evidence-based guideline is derived from robust meta-analysis findings, but individual responses to caffeine may vary. Tailor your caffeine consumption based on personal sensitivity and sleep quality assessments.