Effects of Creatine Supplementation on Athletic Performance in Soccer Players: A Systematic Review and Meta-Analysis.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of double-blind randomized placebo-controlled trials
PubMed 30935142 · doi:10.3390/nu11040757
What was done
Researchers conducted a systematic review and meta-analysis following PRISMA guidelines across PubMed/Medline, Web of Science, Cochrane Library, and Scopus through January 2019. Inclusion was restricted to double-blind, randomized, placebo-controlled trials evaluating creatine supplementation in soccer players regardless of age, sex, or competitive level. Outcomes were categorized by metabolic system (aerobic, phosphagen, and anaerobic) and pooled using a random-effects model to calculate standardized mean differences (SMD, Hedges's g).
What was found
Across 9 included studies: - Aerobic performance showed no significant benefit (SMD -0.05; 95% CI, -0.37 to 0.28; p = 0.78). - Phosphagen metabolism tests (strength, single jump, single sprint, agility) showed no statistically significant improvement (SMD 0.21; 95% CI, -0.03 to 0.45; p = 0.08). - Anaerobic performance tests improved significantly (SMD 1.23; 95% CI, 0.55 to 1.91; p < 0.001). - Wingate test performance demonstrated a large improvement (SMD 2.26; 95% CI, 1.40 to 3.11; p < 0.001).
Why it matters
This review helps explain mixed findings in soccer literature by showing that creatine's ergogenic effects are specific to anaerobic power demands rather than aerobic endurance or single-bout phosphagen efforts.
Limits
The total number of participants across the 9 trials is not stated in the abstract. Study-level heterogeneity, risk of bias, participant demographics (e.g., sex and competitive tiers), and actual on-pitch match performance metrics were not reported in the abstract.
Cited by
- contradicts Literature shows that creatine supplementation in young children participating in sports like soccer improves agility and is safe.