BETA-ALANINE ONLY AFFECTS EXERCISE CAPACITY AND NOT PERFORMANCE
Hobson, R. M., Saunders, B., Ball, G., Harris, R., & Sale, C. (2012). Effects of beta-alanine supplementation on exercise performance: A meta-analysis. Presentation 1838 at the 59th Annual Meeting of the American College of Sports Medicine, San Francisco, California; May 29-June 2, 2012.
Beta-alanine is a substrate of carnosine (which contributes to H+ buffering during high-intensity exercise) and is a popular ergogenic aid for sports performance. A meta-analysis of the published literature was conducted. A comprehensive literature search identified studies suitable for inclusion. Strict exclusion criteria, generally relating to inappropriate methodological design, were applied. Exercise tests were analyzed as a complete group for the overall effect of beta-alanine supplementation compared to a placebo. Due to the mechanisms by which beta-alanine is proposed to have an ergogenic effect, the data were then sub-divided into type of exercise test (capacity, performance); duration of exercise test (<60 seconds, 60-240 seconds, >240 seconds); and the daily and total dose of beta-alanine administered. Mann-Whitney U-tests and Spearmanís correlation coefficients were used to analyze the data.
Fifteen published manuscripts were included in the analysis, which reported the results from 57 exercise tests, using 18 supplementation regimes, and involving 360 participants (174 beta-alanine, 186 placebo). Beta-alanine improved the outcome of exercise tests to a greater extent than placebo. Some of the effect might be explained by the improvement in exercise capacity tests with beta-alanaine. No improvement was seen for performance tests. In line with the purported mechanisms for an ergogenic effect of beta-alanine, exercise tests lasting 60-240 seconds were improved with beta-alanine compared to placebo, as were exercise tests of >240 seconds. In contrast, there was no benefit of beta-alanine on exercise tests lasting <60 seconds. There also was no relationship between the dose of beta-alanine administered and the difference between the effect size of the beta-alanine and placebo groups in the exercise tests.
Implication. Overall, beta-alanine supplementation resulted in a 2.85% improvement in the outcome of an exercise test that measured capacity when a total of 179 g of beta-alanine was supplemented.
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