Abstract
The interest in the benefits of caffeine in combat sports has grown exponentially in the last few years, evidenced by the significant rise of post-competition urine caffeine concentration. We conduct a systematic review and meta-analysis on the effects of caffeine on different performance variables in combat sports athletes. In total, we included 25 studies. All studies included had blinded, and cross-over experimental designs, and we conducted a risk of bias analysis. For nonspecific outcomes, there was an ergogenic effect of caffeine on vertical jump height (SMD: 0.38; 95% CI: 0.04, 0.71) and reaction time (SMD: −0.98, 95% CI: −1.46,−0.50). For outcomes specific to combat sports, there was an increase in the number of throws with caffeine in the Special Judo Fitness Test (SMD: 0.62; 95% CI: 0.14, 1.09). Caffeine ingestion increased the number of offensive actions during combats (SMD: 0.40; 95% CI: 0.06, 0.74). Caffeine ingestion increased the duration of offensive actions during combat (SMD: 0.58; 95% CI: 0.21, 0.96). Finally, caffeine ingestion increased blood lactate concentration after bout 1 (SMD: 1.35) bout 2 (SMD: 1.43) and bout 3 (SMD: 1.98). Overall, athletes competing in combat sports may consider supplementing with caffeine for an acute increase in exercise performance.
Author contributions
JDL, JG designed the research, conducted the searches and screening process; JDL, JG and JDC extracted the data, interpreted the data analysis, and led the drafting of the manuscript. JDL, JG, DD, JB, SLJ and JDC, writing—review and editing the manuscript. All authors have read and approved the final version of the manuscript, and agree with the order of presentation of the authors.
Conflicts of interest
Javier Diaz-Lara, Jozo Grgic, Daniele Detanico, Javier Botella, Sergio L. Jiménez and Juan Del Coso declare they have no conflicts of interest.
Funding
The authors disclose no funding was received for this project.
Correction Statement
This article has been corrected with minor changes. These changes do not impact the academic content of the article.