Effects of Different Dietary Supplements on Swimming Performance: A Systematic Review and Network Meta-Analysis.

BACKGROUND

Nutritional supplements are widely used by swimmers, but the effectiveness of various supplements and the identification of the most effective intervention require further investigation.

PURPOSE

This paper evaluated and compared the effectiveness of various nutrition-based interventions on swimming performance through both direct and indirect comparisons.

METHODS

PubMed, Embase, Web of Science, Cochrane Library, and SPORTDiscus databases were thoroughly searched up to 4 April 2024. The risk of bias was judged using the Cochrane risk of bias tool. A random-effect model was adopted to compute standardized mean differences (SMD) and 95% confidence intervals (CI).

RESULTS

L-arginine (Arg) demonstrated superior performance to the placebo (SMD = -1.66, 95% CI [-2.92, -0.44]), emerging as the most effective intervention for reducing 100 swimming time (SUCRA = 89.5%). Beta-alanine (BA) was the best intervention for improving blood lactate (SUCRA = 80%). Creatine combined with sodium bicarbonate (Creatine_NaHCO) significantly increased blood pH compared to the placebo (SMD = 3.79, 95% CI [1.85, 5.80]), with a SUCRA score of 99.9%, suggesting it is the most effective intervention for this parameter. No prominent differences were noted among the interventions in 50 m time, 200 m time, heart rate, and body mass.

CONCLUSIONS

Dietary supplements might provide benefits for improving swimming performance. Arg emerged as the most efficacious modality for reducing 100 m time. BA proved to be the preeminent strategy for decreasing blood lactate. Creatine_NaHCO was distinguished as the optimal approach for improving blood pH.