SynthesisFrontiers in physiology2025
Does caffeine intake enhance physical and physiological performance in swimmers? a systematic review and meta-analysis.
Synthesis in Frontiers in physiology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
1 citing paper in PubMed, 1 synthesis or guideline pooled it.
- Caffeine makes a splash: a systematic review and multilevel meta-analysis exploring the effects of caffeine intake on swimming performance.Journal of the International Society of Sports Nutrition · 2026Pooled it
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Authors and funding
8 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Background: Acute caffeine intake is widely used by athletes to enhance performance, and its ergogenic effects are well-established in several land-based sports. However, whether similar benefits apply to swimming remains unclear. Objective: This systematic review and meta-analysis (SRMA) evaluates the effects of acute caffeine intake on swimmers' physical and physiological performance. Methods: Following PRISMA guidelines, studies were retrieved from five databases: Cochrane Library, Web of Science, Embase, PubMed, and SPORTDiscus. Eligible trials assessed acute caffeine effects on physical (25 m time, 50 m time, swimming velocity, jump height, power) and physiological (blood lactate, blood pH) outcomes in swimmers. A random-effects model was used to compute standardized mean differences (SMD) and 95% confidence intervals (CI). Subgroup analyses were conducted based on the type of outcome measures used. Results: A total of ten randomized crossover trials involving 121 participants were included. Acute caffeine intake showed no significant improvement in 25 m time (SMD = -0.14; 95% CI: -0.91, 0.63; p = 0.73), 50 m time (SMD = -0.06; 95% CI: -0.50, 0.37; p = 0.78), swimming velocity (SMD = 0.47; 95% CI: -1.97, 2.92; p = 0.70), jump height (SMD = 0.12; 95% CI: -0.72, 0.96; p = 0.78) and power (SMD = 0.05; 95% CI: -0.78, 0.89; p = 0.90). Additionally, no significant effects were observed for blood lactate (SMD = 0.81; 95% CI: -0.07, 1.70; p = 0.07), and blood pH (SMD = 0.01; 95% CI: -1.86, 1.88; p = 0.99). Conclusion: This SRMA found no significant evidence that acute caffeine supplementation improves swimming performance, either physical or physiological. Given the small number and sample sizes of included studies and the presence of heterogeneity, the findings should be regarded as preliminary. Larger, well-designed trials are needed to clarify caffeine's true effects on swimmers' performance and to inform practical recommendations.
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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.