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Caffeine supplementation may impair sleep quality and increase insomnia risk in athletes

This systematic review of 9 randomized controlled trials found that caffeine supplementation can have detrimental effects on sleep parameters such as sleep quality, duration, efficiency, and onset latency in athletes. The effects varied based on timing of consumption, dose, and habitual caffeine use.

Last updated: Jul 7, 2026•1 RCTs•📖 Read as article →

Evidence Score

Evidence Score42/100
Human RCT★★☆☆☆
Meta-analysis☆☆☆☆☆
Mechanism★★★★★
Safety★★★★☆
Confidencelow

Study Evidence

Study 1. Does caffeine supplementation affect sleep in athletes? A systematic review of nine randomized controlled trials.

observational

Bodur M, Barkell J, Li X, Sajadi Hezaveh Z · Clinical nutrition ESPEN (2025)

Participants: N/A
Duration: N/A
Intervention: Caffeine supplementation
Outcome: Sleep parameters (duration, quality, efficiency, number of awakenings, sleep onset latency, insomnia)
Effect Size: N/A
Population: Professional athletes

Result:

PubMed: 39551351DOI: 10.1016/j.clnesp.2024.11.007

Mechanism Graph

Caffeine blocks adenosine receptors in the brain
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Reduces sleep pressure and delays sleep onset
↓
Alters sleep architecture and reduces slow-wave sleep
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Result: Increased sleep onset latency, reduced sleep quality, and higher risk of insomnia

Limitations

  • ⚠Only 9 trials were eligible, limiting generalizability
  • ⚠Variability in study designs (timing, dose, exercise protocols) prevents definitive conclusions

Frequently Asked Questions

Does caffeine always harm sleep in athletes?▼

No, effects vary based on timing, dose, habitual use, and individual sensitivity. Some athletes may not experience significant sleep disruption.

What sleep parameters are most affected by caffeine?▼

Sleep onset latency, sleep quality, sleep efficiency, and number of awakenings are commonly affected, with insomnia being a likely outcome.

How can athletes minimize caffeine's impact on sleep?▼

Athletes should consider individual responses, avoid caffeine close to bedtime, and adjust dose based on habitual use and exercise timing.

Is caffeine supplementation recommended for athletes despite sleep risks?▼

Caffeine may enhance performance, but its detrimental effects on sleep and recovery should be weighed. Personalized supplementation is advised.

Products

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References

  1. 1.Bodur M, Barkell J, Li X, Sajadi Hezaveh Z. "Does caffeine supplementation affect sleep in athletes? A systematic review of nine randomized controlled trials.." Clinical nutrition ESPEN, 2025. PMID: 39551351 DOI: 10.1016/j.clnesp.2024.11.007
Disclaimer: This content is for educational purposes only and is not medical advice. Evidence scores reflect the quality and quantity of available research, not clinical recommendations. Always consult a healthcare professional before starting any supplement or intervention.