Effects of β-alanine supplementation on kickboxing-specific anaerobic performance, neuromuscular power, and strength endurance: A randomized, double-blind, placebo-controlled trial

Clinical Snapshot

Key Findings

• P Value: KASTtotal: p < 0.001; push-ups: p = 0.023; pull-ups: p = 0.004

• Effect Size: Large effect for KASTtotal (ηp² = 0.358), medium-to-large effects for strength endurance

• Primary Outcome: Significant improvement in KASTtotal (total anaerobic performance)

• Nnt Or Sensitivity: Not calculable from available data

• Confidence Interval: Not reported

Clinical Application

β-alanine is readily available as an over-the-counter dietary supplement. 4-week supplementation protocol is practical for athletes β-alanine is not scheduled by the TGA and is available as a complementary medicine. Athletes should ensure products are batch-tested for prohibited substances. Consider ASADA guidelines for supplement use Trained combat sport athletes, particularly kickboxers and martial artists engaged in high-intensity, repeated-effort activities

Abstract

β-Alanine (BA) elevates skeletal muscle carnosine and may improve repeated high-intensity performance; however, evidence in kickboxing is limited. This study investigated the effects of 4-week BA supplementation on sport-specific kickboxing anaerobic performance, neuromuscular power, and strength endurance in trained male kickboxers. Twenty-eight athletes were randomly assigned to BA (6.4 g·day ⁻ ¹; n = 14) or placebo (n = 14) in a double-blind, placebo-controlled design. Pre- and post-intervention assessments included the Kickboxing Anaerobic Speed Test (KAST₁-₅, KASTbest, KASTtotal, Performance Decrement Index [PDI]), neuromuscular power (countermovement jump [CMJ], squat jump [SJ]), and strength endurance tests (push-up, pull-up). Baseline differences were tested via t-tests, effect sizes calculated according to Hedges' g formula. Group × time effects were analyzed using two-way repeated-measures ANOVA with partial eta squared (ηp²) effect sizes. Baseline measures were comparable (all p > 0.05). After supplementation, no significant group × time interactions emerged for CMJ (p = 0.148), SJ (p = 0.717), KAST₁-₅ (all p > 0.05), KASTbest (p = 0.071), or PDI (p = 0.454). However significant improvements were observed in the BA group for KASTtotal (F(1,26) = 14.49, p < 0.001, ηp² = 0.358), push-ups (F(1,26) = 5.89, p = 0.023, ηp² = 0.185), and pull-ups (F(1,26) = 9.79, p = 0.004, ηp² = 0.274). Four weeks of BA supplementation enhanced total anaerobic performance (KASTtotal) and upper-body strength endurance (push-up, pull-up), while no significant changes were observed in neuromuscular jump performance (CMJ, SJ). BA appears to be a practical ergogenic aid for improving repeated-effort and strength-endurance capacity in kickboxing. Clinical trial registration ClinicalTrials.gov (NCT07319052).

References

1. 1.Küçük, F. H., Gençoğlu, C., Ateş, O., Da Silva Duarte, J. D. R., Belošević, D., Çabuk, S., İnaç, M. R., Ulupınar, S., & Özbay, S. (2026). Effects of β-alanine supplementation on kickboxing-specific anaerobic performance, neuromuscular power, and strength endurance: A randomized, double-blind, placebo-controlled trial. *PLoS One*, Article 0346898. https://doi.org/10.1371/journal.pone.0346898