ABSTRACT
The aim of this investigation was to perform a systematic review and meta-analysis to determine the efficacy of the acute ingestion of caffeine (from 3 to 6 mg/kg) to increase performance on variables related to team sports. A systematic review was performed in scientific databases from January to April 2018. All studies included had cross-over experimental designs comparing caffeine to an identical placebo condition. A meta-analysis was performed using the random effects model and pooled standardized mean differences (Glass’s Δ). Thirty-four studies published between 2001 and 2018 were included in the analysis. The meta-analysis revealed that caffeine increased single (Δ;95% confidence intervals = 0.19;0.14–0.25; p < 0.01) and repeated jump height (0.29;0.16–0.42; p < 0.01), single (0.16;0.02–0.30; p = 0.03) and repeated sprint velocity (0.14;0.03–0.25; p = 0.02), and reduced the time to complete agility tests (0.41;0.04–0.77; p = 0.03). During team sport matches, caffeine increased total running distance (0.41;0.20–0.62; p < 0.01), distance covered at sprint velocity (0.36;0.12–0.59; p < 0.01) and the number of sprints (0.44;0.18–0.69; p < 0.01). The acute ingestion of a moderate dose of caffeine had a small but significant positive effect on several aspects related to physical performance in team sports.
Acknowledgments
The authors of this investigation want to acknowledge the labor of all the researchers that have conducted the investigations that allowed this review and meta-analysis. Specially, we want to acknowledge the researchers that have sent us data- beyond the information included in their studies- to improve the meta-analysis.
Disclosure statement
No potential conflict of interest was reported by the authors.