Caffeine is one of the most popular ergogenic (intended to enhance performance, stamina, or recovery) aids on the market, with research frequently demonstrating efficacy in both physical and cognitive domains.
Caffeine's performance benefits have been proven consistently, and it can deliver a real boost for individuals engaging in training or competition. However, to maximize the benefits caffeine offers, its use must be balanced with the potential for negative effects on sleep, a crucial component of peak performance.
This meta-analysis dives into the literature and the potential negative effects of caffeinated evening training and caffeine's negative impact on sleep performance.
PMID: 41003623
Study Summary
This meta-analysis examined studies looking at the potential negative interactions between consuming caffeine (3-6 mg/kg of body mass) before evening training and competition (after 4:00pm).
Vitality Takeaway
After examining 10 studies looking at these effects in 128 athletes, authors found:
- Caffeine consumption resulted in a significant -4.87% decrease in sleep efficiency (the % of time spent asleep vs. total time in bed).
- Caffeine decreased sleep efficiency by 32.47 minutes (non-significant).
- Athletes consistently perceived substantial sleep disturbances regardless of objective measurements following caffeine consumption.
Researchers point to caffeine's interaction with adenosine receptors as the possible mechanism. Caffeine blocks these receptors, eliciting alertness and other stimulatory benefits associated with intake.
This blockage also interacts with other neurotransmitter processes, such as norepinephrine, dopamine, acetylcholine, serotonin, glutamate, and GABA release, which are all regulated by the body to drive sleep performance.
This systematic review offers evidence-based strategies for athletes to optimize caffeine use surrounding training or competition while minimizing its impact on sleep.
- When utilizing caffeine to boost training quality or competitive performance, athletes should determine personal caffeine cut-off times through testing. Start with around 3 mg/kg taken 4–6 hours before bedtime, and track both objective and subjective performance impacts and sleep quality to determine personal timing thresholds that balance benefits with sleep quality (to ensure optimal recovery and adaptation following effort).
- Female athletes on oral contraceptives may need longer elimination windows due to slower caffeine metabolism.
- If caffeine use before evening competition is unavoidable as a performance enhancer, athletes should prioritize the lowest effective dose and consume it as early as possible to protect sleep and recovery.
Vitality Application
Athletes must walk a fine line that promotes physical performance, regardless of the time of day, while also allowing for proper recovery and growth processes, such as sleep. Striking this balance will help optimize performance and the processes that support recovery and adaptation, leading to continued improvement.
Recommendation: Supplement with 3-6mg of caffeine per kg of body mass to enhance performance in training and competition, but observe a measured personal cutoff time (start with no later than 4:00 pm) to protect sleep and recovery following the effort.
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