The effect of Beta-Alanine supplementation on isokinetic force and cycling performance in highly trained cyclists
Howe, ST and Bellinger, PM and Driller, MW and Shing, CM and Fell, JW, The effect of Beta-Alanine supplementation on isokinetic force and cycling performance in highly trained cyclists, International Journal of Sports Nutrition and Exercise Metabolism, 23, (6) pp. 562-570. ISSN 1526-484X (2013) [Refereed Article]
β-alanine may benefit short duration, high-intensity exercise performance. The aim of this randomised, double-blind, placebo controlled study was to examine the effects of β-alanine supplementation on aspects of muscular performance in highly-trained cyclists. Sixteen highly-trained cyclists (mean±SD; age=24±7yr; mass=70±7kg; VO2max=67±4mL.kg-1•min-1) supplemented with either β-alanine (n=8, 65mg.kg-1BM) or a placebo (n=8, dextrose monohydrate) over four weeks. Pre- and post-supplementation cyclists performed: 1) a four-minute maximal cycling test to measure average power and 2) 30 reciprocal maximal isokinetic knee contractions at a fixed angular velocity of 180°•sec-1 to measure average power/repetition, total work done (TWD) and fatigue index (%). Blood pH, lactate (La-) and bicarbonate (HCO₃-) concentrations were measured pre- and post-isokinetic testing at baseline and following the supplementation period. β-alanine supplementation was 44% likely to increase average power output during the four-minute cycling time-trial when compared to the placebo, although this was not statistically significant (p=0.25). Isokinetic average power/repetition was significantly increased post-β-alanine supplementation compared to placebo (β-alanine: 6.8±9.9W, placebo: -4.3±9.5W, p=0.04, 85% likely benefit), while fatigue index was significantly reduced (p=0.03, 95% likely benefit). TWD was 89% likely to be improved following β-alanine supplementation, however this was not statistically significant (p=0.09). There were no significant differences in blood pH, lactate and HCO₃- between groups (p>0.05). Four weeks of β-alanine supplementation resulted in worthwhile changes in time-trial performance and short-duration muscular force production in highly-trained cyclists.