title: The effect of beta-alanine supplementation on power performance during repeated sprint activity.
abstract: The dipeptide carnosine has been shown to contribute to the buffer capacity of hydrogen ions (H) during intense exercise. Increasing skeletal muscle carnosine levels through beta-alanine (BA) supplementation has been shown to maintain acid-base balance, delay fatigue, and improve exercise performance. We designed this study to examine the effect of 5 weeks of BA supplementation on repeat high-intensity sprint performance. Nineteen, physically active, college men were divided into 2 groups (control [C], n = 10 or BA, n = 9). We performed double-blind placebo-controlled study where subjects ingested 4 g per day during the first week and 6 g per day over the next 4 weeks of a placebo (rice flour) or a BA supplement. Subjects completed 2 sets of 5 5-second sprints with 45-second recovery separated by 2 minutes of active recovery. All tests were conducted on a non-motorized treadmill against a resistance of 15% of the participant's body weight. We recorded horizontal power (HP) of the running sprint. Post-exercise capillary blood samples were analyzed for lactate to determine the metabolic demands. There were no significant between-group differences (p > 0.05) in HPpeak or HPmean for the repeat sprint protocol. No significant between-group differences were found for performance decrement (% fatigue) for HPpeak or HPmean. In addition, no significant interactions were observed. Post-exercise blood lactate values were similar pre and post supplementation in both groups. The results of this study clearly indicate that 5 weeks of BA supplementation provides no benefit for repeat sprint performance.
authors.affiliation: Exercise and Sport Science Department, University of Wisconsin-La Crosse, La Crosse, Wisconsin, USA. kaitlin.sweeney@gmail.com
authors.forename: Kaitlin M
authors.initials: KM
authors.lastname: Sweeney
authors.forename: Glenn A
authors.initials: GA
authors.lastname: Wright
authors.forename: A
authors.initials: A
authors.lastname: Glenn Brice
authors.forename: Scott T
authors.initials: ST
authors.lastname: Doberstein
mesh_terms: D054874:Athletic Performance / Q000502:physiology*; D019587:Dietary Supplements; D004311:Double-Blind Method; D006801:Humans; D007773:Lactates / Q000097:blood; D008297:Male; D018763:Muscle Fatigue / Q000187:drug effects / Q000502:physiology; D010807:Physical Endurance / Q000187:drug effects / Q000502:physiology; D012420:Running / Q000502:physiology*; D055815:Young Adult; D015091:beta-Alanine / Q000494:pharmacology*
chemical_list: D007773:Lactates; D015091:beta-Alanine