Effect of Chronic Beta-Alanine Supplementation on Physical Performance and Lactate Markers in Elite Marathon Runners Living at Altitude: A Randomized Double-Blind Clinical Trial

Torres Vera T.D.; Castillo-Paredes A.; Iman Torres A.J.; Narrea Vargas J.J. · Sport Mont (2026) · DOI: 10.26773/smj.260214

Resumen

This study aimed to evaluate the effect of chronic beta-alanine supplementation on physical performance and blood lactate markers in elite marathon runners living at altitude. A randomized, double-blind, placebo-controlled clinical trial with a pre–post intervention design was conducted. Twelve athletes residing at 3259–3399 m above sea level were randomly assigned to a beta-alanine group (6 g·day⁻¹; n=5) or a placebo group (n=6) for four weeks. Before and after the intervention, blood lactate markers and physical performance were assessed using a maximal incremental running test on a 400 m track. Linear mixed-effects models showed no statistically significant group x time effects for maximal lactate concentration (β = -1.29 mmol·L⁻¹; 95% CI: -4.81 to 2.23), post–rest lactate difference (β = -1.77 mmol·L⁻¹; 95% CI: -5.67 to 2.12), or lactate clearance percentage (β = -19.27%; 95% CI: -54.4 to 15.8). Similarly, no meaningful effects were observed for maximal sustained running speed (β = -0.15 km·h⁻¹; 95% CI: -2.12 to 1.82), total exercise time (β = -0.42 min; 95% CI: -2.51 to 1.67), or distance covered (β = -0.21 km; 95% CI: -0.79 to 0.36). In conclusion, four weeks of beta-alanine supplementation did not produce detectable improvements in physical performance or lactate markers in elite marathon runners living at altitude, with effect estimates indicating small and imprecise differences between groups.

Instituciones: Universidad Nacional de la Amazonía Peruana; Universidad Científica del Sur