Abstract / Summary
Aim Soccer places repeated demands on short-duration, high-intensity performance, including sprints, accelerations, jumps, and technical actions performed over the course of a match. Because these efforts depend heavily on rapid adenosine triphosphate (ATP) resynthesis, creatine is a plausible ergogenic aid for soccer players. However, findings in soccer-specific studies have been inconsistent, and previous reviews have addressed narrower questions using smaller evidence sets. This systematic review therefore examined the effects of creatine supplementation on performance, body composition, and recovery/fatigue-related outcomes in soccer players.Methods PubMed, Scopus, and Web of Science were searched from inception to 15 May 2025 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) 2020 statement. We included controlled clinical trials of creatine supplementation in male or female soccer players of any age or competitive level when an eligible placebo, control, or comparison condition was available. Outcomes were grouped into performance, body composition, and recovery/fatigue domains. Domains from the revised Cochrane risk-of-bias tool for randomised trials (RoB 2) and the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool were used to produce study-level methodological summaries rather than formal result-specific risk-of-bias assessments. Because the studies differed substantially in design, supplementation protocols, populations, and outcomes, findings were synthesised qualitatively rather than pooled in a meta-analysis.Results Source-level verification left 45 eligible reports representing 41 unique studies: 28 randomised parallel-group studies, 2 randomised crossover/repeated-condition studies, and 11 non-randomised or allocation-unverifiable controlled studies. Some trials reported favourable findings for repeated-sprint performance, anaerobic power, and muscular strength, but the comparative evidence was inconsistent and the certainty of evidence was very low. Findings for vertical jump performance and technical skills were mixed, while change-of-direction and endurance outcomes showed no consistent benefit. Recovery- and fatigue-related findings were also largely null or inconsistent. Body mass often increased, particularly after loading protocols, whereas evidence for gains in lean mass was limited and inconsistent.Conclusion The soccer-specific evidence for creatine supplementation remains suggestive rather than conclusive. Favourable findings have been reported for some repeated-sprint, anaerobic-power, and strength outcomes, but the comparative evidence is heterogeneous, often limited by unclear or nonsignificant between-group effects, and of very low certainty. Firm conclusions about efficacy are therefore not possible. Body mass commonly increased, especially after loading protocols, while effects on lean mass, endurance, change-of-direction ability, and recovery/fatigue-related outcomes remain uncertain.