Effect of β-Alanine Supplementation on Repeated Sprint Ability and Responses of Blood Lactate and Bicarbonate in Male Soccer Players

Abstract

This study was designed to investigate the effect of β-alanine supplementation on sprint time during repeated sprint ability test and blood lactate and bicarbonate responses to the test. Eighteen male soccer players were randomly divided into two groups (β-alanine, n=9 (24.31±2.14 yrs) or placebo, n=9 (23.98±2.07)). We conducted a randomized, double-blind, parallel-group, placebo-controlled study in which participants ingested 4.8 g/day for four weeks of a β-alanine supplement or a placebo. Athletes completed seven repetitions of 30 m interspersed with 30 s recovery intervals. The test was performed before and after four weeks of supplementation. Blood samples were collected from each participant in both groups before and after the test, pre- and post-supplementation to measure lactate and bicarbonate levels. Data showed that the sixth and seventh repetitions were significantly faster after β-alanine supplementation than the placebo (sixth repetition: 3.74±0.04 s vs 3.91±0.09 s, seventh repetition: 3.91±0.07 s vs 4.12±0.14 s, p=0.001, p=0.002, respectively). Before supplementation, however, no differences existed between groups for any sprint time in all repetitions (p>0.05). Data revealed significantly higher lactate concentration in the β-alanine than the placebo after the finish of the test at both pre-supplementation (p=0.022), and post-supplementation (p=0.017). No differences noted between groups in bicarbonate at all measured points. In conclusion, β-alanine supplementation has a beneficial effect on repeated sprint performance in soccer players, probably due to effective vasodilatation mechanism.