title: The effect of beta-alanine supplementation on isokinetic force and cycling performance in highly trained cyclists.
abstract: Beta-alanine may benefit short-duration, high-intensity exercise performance. The aim of this randomized double-blind placebo-controlled study was to examine the effects of beta-alanine supplementation on aspects of muscular performance in highly trained cyclists. Sixteen highly trained cyclists (mean ± SD; age = 24 ± 7 yr; mass = 70 ± 7 kg; VO2max = 67 ± 4 ml · kg(-1) · min(-1)) supplemented with either beta-alanine (n = 8, 65 mg · kg - 1BM) or a placebo (n = 8; dextrose monohydrate) over 4 weeks. Pre- and postsupplementation cyclists performed a 4-minute maximal cycling test to measure average power and 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 postisokinetic testing at baseline and following the supplementation period. Beta-alanine supplementation was 44% likely to increase average power output during the 4-minute cycling time trial when compared with the placebo, although this was not statistically significant (p = .25). Isokinetic average power/repetition was significantly increased post beta-alanine supplementation compared with placebo (beta-alanine: 6.8 ± 9.9 W, placebo: -4.3 ± 9.5 W, p = .04, 85% likely benefit), while fatigue index was significantly reduced (p = .03, 95% likely benefit). TWD was 89% likely to be improved following beta-alanine supplementation; however, this was not statistically significant (p = .09). There were no significant differences in blood pH, lactate, and HCO3- between groups (p > .05). Four weeks of beta-alanine supplementation resulted in worthwhile changes in time-trial performance and short-duration muscular force production in highly trained cyclists.
authors: Sport Performance Optimisation Research Team, School of Human Life Sciences, University of Tasmania, Tasmania, Australia.
authors: Samuel T
authors: ST
authors: Howe
authors: Phillip M
authors: PM
authors: Bellinger
authors: Matthew W
authors: MW
authors: Driller
authors: Cecilia M
authors: CM
authors: Shing
authors: James W
authors: JW
authors: Fell
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D056352:Athletes; D054874:Athletic Performance; D001642:Bicycling / Q000502:physiology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood; D008297:Male; D053580:Muscle Strength / Q000187:drug effects*; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000187:drug effects; D064133:Sports Nutritional Physiological Phenomena; D055815:Young Adult; D015091:beta-Alanine / Q000008:administration & dosage*
chemical_list: D015091:beta-Alanine; D019344:Lactic Acid