Effects of Acute Caffeine Ingestion on Repeated Sprint Ability: A Systematic Review and Meta-Analysis

Background/Objectives: Caffeine is widely recognized as an ergogenic aid, yet evidence regarding its acute effects on repeated sprint ability (RSA) remains inconsistent. This systematic review and meta-analysis aimed to evaluate the effects of acute caffeine ingestion on RSA across different populations, exercise modalities, and dosage levels. Methods: A comprehensive literature search was conducted in the PubMed, EBSCO, Cochrane Library, Web of science, and Scopus databases. Data were pooled using the weighted mean difference (WMD) with 95% confidence interval (CI). Results: Thirteen studies met the inclusion criteria. Acute caffeine ingestion significantly enhanced RSA peak power output (PPO) compared with placebo (WMD, 5.28; 95% CI, 2.49 to 8.07; p = 0.0002). Subgroup analyses revealed significant improvements in both males (WMD, 13.11; 95% CI, 5.63 to 20.59; p = 0.0006) and females (WMD, 4.03; 95% CI, 1.10 to 6.97; p = 0.007). A caffeine dose of ≥6 mg/kg body weight (BW) produced greater ergogenic benefits (WMD, 6.67; 95% CI, 3.32 to 10.02; p < 0.0001) than lower doses (WMD, 2.16; 95% CI, -2.87 to 7.19; p = 0.40). Moreover, a more pronounced enhancement was observed in cycling-based RSA (WMD, 8.77; 95% CI, 1.98 to 15.56; p = 0.01) compared with running-based protocols (WMD, 4.56; 95% CI, 1.58 to 7.55; p = 0.003). Conclusions: Acute caffeine ingestion significantly enhances RSA, particularly at doses ≥6 mg/kg BW. This effect is consistent across both male and female participants, with no statistically significant sex difference observed in the pooled analysis. These findings reinforce caffeine's role as an effective ergogenic aid for optimizing high-intensity intermittent performance, with the strongest benefits evident in cycling exercise.