Acute effects of citrulline malate and L-arginine, alone and in combination, on anaerobic performance indicators in highly trained taekwondo athletes

Purpose This study aimed to examine the acute effects of citrulline malate (CITMAL), L-arginine (L-ARG), and their combined supplementation on anaerobic power output during a standardized Wingate test, as well as on post-exercise agility and countermovement jump performance in highly trained taekwondo athletes. Methods The study was designed as a double-blind, randomized, crossover trial. Sixteen highly trained male taekwondo athletes ( ≥ 18 years) completed four experimental conditions— L-ARG (6 g), CITMAL (8 g), combined L-ARG + CITMAL, and placebo (PLA)—administered in powder form 1 h before exercise, with each trial separated by 72 h. Anaerobic power was assessed using a standardized Wingate test, followed by post-exercise agility and countermovement jump evaluations. Data were analyzed using repeated-measures analysis of variance with appropriate post hoc adjustments, and statistical significance was set at P < 0.05. Results Compared with placebo, combined CITMAL + L-ARG supplementation significantly increased peak power output (747.85 ± 115.61 vs. 631.61 ± 108.40 W, P < 0.001) and relative peak power (11.72 ± 1.35 vs. 9.94 ± 1.16 W⋅kg –1 , P < 0.001). Agility performance improved by approximately 10.5% (16.26 ± 0.81 vs. 18.17 ± 0.69 s, P < 0.001), while CMJ height increased by 22.9% (32.36 ± 3.43 vs. 26.34 ± 2.75 cm, P < 0.001). Post-exercise blood lactate concentrations were also significantly lower following combined supplementation (12.93 ± 1.12 vs. 15.20 ± 1.23 mmol⋅L –1 , P < 0.001). Conclusion The findings of this study indicate that combined L-ARG and CITMAL supplementation is associated with improvements in selected anaerobic performance, agility, and countermovement jump outcomes in highly trained taekwondo athletes. Compared with PLA and single-supplement conditions, the combined supplementation elicited more favorable responses in key Wingate-derived power variables and post-exercise performance measures. Nevertheless, these results should be interpreted cautiously, and further well-controlled studies are required to confirm the observed effects and to clarify the underlying physiological mechanisms.