المستخلص: |
This study was designed to investigate the effect of β-alanine loading (BA) on sprint time during repeated sprint 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 performed randomized, double- blind, parallel-group, placebo-controlled study where participants ingested 4.8 g per day for 4 weeks of a ß-alanine supplement or a placebo. Athletes completed 7 repetitions of 30 m interspersed by 30-second recovery interval. Repeated sprint test was performed before and after 4 weeks of supplement intervention. Blood samples were collected from each participant in both groups to assay blood lactate and bicarbonate before and after repeated sprint test (at 4 points). Independent t-test showed that the sixth and seventh repetitions were significantly faster after β -alanine loading than placebo (Pla) (3.74 ± 0.04 seconds vs 3.91 ± 0.09 s, 3.91 ± 0.07 seconds 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 ß-alanine than the Pla at the points of pre-supplementation (post- test) (p = 0.022), and post-supplementation (posttest) (p = 0.017). No significant difference was noted between ß-alanine and Pla in bicarbonate at all points. In conclusion, β -alanine loading has beneficial effect on repeated sprint performance in soccer players probably due to vasodilatation mechanism.
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