Effects of creatine supplementation on muscle strength gains-a meta-analysis and systematic review

Creatine (Cr) is a widely utilized nutritional supplement. Empirical evidence indicates that Cr supplementation significantly elevates intramuscular Cr content, thereby providing an energy substrate reservoir for exercise performance and facilitating improvements in muscle strength. Although numerous studies have examined the relationship between Cr and muscle strength, comprehensive investigations into population-specific ergogenic responses, optimal Cr dosage, and concomitant training intensity remain limited. These parameters are critical determinants for maximizing the efficacy of Cr supplementation. Against this backdrop, this study adopts meta-analysis, integrating conventional and Robust Variance Estimation (RVE) models, to comprehensively evaluate the intervention effects of Cr supplementation across three dimensions: population applicability, dosage optimization, and training intensity (PROSPERO registration number: CRD42024547697). It aims to provide evidence-based support for precise clinical application and subsequent research directions.

Results

Results showed no statistical difference in baseline muscle strength between the Cr intervention group and the control group; after intervention, the Cr group exhibited significant strength gains. Further subgroup analysis revealed: untrained individuals had greater muscle strength improvements than trained ones; the low-to-moderate dose group showed better effects than the high-dose group; high-intensity training had more significant effect sizes than low-intensity training; and no definitive conclusion was reached on muscle strength improvements between middle-aged/elderly and young populations.

Conclusion

Cr supplementation significantly improves muscle strength in the general population. Specifically: untrained individuals show greater muscle strength improvements; low-dose supplementation combined with high-intensity exercise yields better effects; no definitive conclusion was reached on effect differences between middle-aged/elderly and young populations, requiring larger-sample studies for more precise effect size analysis.