Abstract

BACKGROUND: This study aimed to investigate the effects of a high-dose beta-alanine (BA) supplementation on physical performance, blood lactate concentration, and ratings of perceived exertion (RPE) in trained futsal players. METHODS: Sixteen trained futsal players participated in a randomized, parallel, double-blind experiment, completing a two-week supplementation period with either 12 g/day of BA (n = 8; age: 19 ± 2 years; height: 1.78 ± 0.03 m; body mass: 68.5 ± 5.4 kg) or a placebo (PLA) (n = 8; age: 18 ± 1 years; height: 1.74 ± 0.08 m; body mass: 65.6 ± 6.4 kg). Athletes completed the futsal intermittent endurance test (FIET) and a 30-m speed test before and after supplementation. Plasma lactate levels were measured before, immediately after, and three minutes post-FIET, while RPE was assessed during each FIET stage. RESULTS: There was a significant main effect of time for distance covered in the FIET (Pre-BA: 1618.13 ± 268.14 m; Post-BA: 1857.50 ± 277.81 m; Pre-PLA: 1519.13 ± 243.19 m; Post-PLA: 1621.88 ± 323.65 m; p = 0.003; ηp2  = 0.73), while no significant interaction effect was revealed for FIET (p = 0.147; ηp2  = 0.27). Furthermore, no significant interaction effects were found in the 30-m sprint test (p = 0.149; ηp2  = 0.27, Pre-BA: 4.33 ± 0.25 s; Post-BA: 4.22 ± 0.124 s; Pre-PLA: 4.33 ± 0.26 s; Post-PLA: 4.37 ± 0.22 s). Neither plasma lactate levels nor RPE showed significant main effects of treatment or timepoint (all p > 0.5). Conclusion: Two weeks of high-dose BA supplementation did not have an ergogenic impact on the distance covered during the intermittent endurance test, sprint performance, blood lactate, or RPE in trained futsal players.