Supplements

Caffeine supplementation in athletes may impair sleep quality and duration, particularly when consumed close to bedtime or in high doses.

This systematic review of nine randomized controlled trials found that caffeine supplementation can have detrimental effects on sleep parameters in athletes, including reduced sleep quality, quantity, and efficiency, as well as increased sleep onset latency and number of awakenings. The effects vary based on timing of consumption, habitual caffeine use, and dose.

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
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Alters sleep architecture and reduces slow-wave sleep
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Result: Impaired sleep quality and recovery

Limitations

  • ⚠Only nine trials were eligible, limiting generalizability
  • ⚠Heterogeneity in study designs, caffeine doses, timing, and athlete populations

Frequently Asked Questions

Does caffeine always harm sleep in athletes?▼

No, the effects vary depending on timing of consumption relative to sleep and exercise, habitual caffeine use, and dose. Some athletes may be less affected.

What sleep parameters are most affected by caffeine?▼

Sleep onset latency, sleep quality, sleep efficiency, number of awakenings, and overall sleep duration can be negatively impacted.

Why might caffeine affect sleep in athletes specifically?▼

Athletes often use caffeine for performance enhancement, but its adenosine-blocking effects can interfere with sleep, which is critical for recovery.

How many studies were included in this review?▼

Nine randomized controlled trials were included from an initial pool of 1469 records.

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.