title: Effects of beta-alanine supplementation on the onset of neuromuscular fatigue and ventilatory threshold in women.
abstract: This study examined the effects of 28 days of beta-alanine supplementation on the physical working capacity at fatigue threshold (PWCFT), ventilatory threshold (VT), maximal oxygen consumption (VO2-MAX), and time-to-exhaustion (TTE) in women. Twenty-two women (age+/-SD 27.4+/-6.1 yrs) participated and were randomly assigned to either the beta-alanine (CarnoSyn) or Placebo (PL) group. Before (pre) and after (post) the supplementation period, participants performed a continuous, incremental cycle ergometry test to exhaustion to determine the PWCFT, VT, VO2-MAX, and TTE. There was a 13.9, 12.6 and 2.5% increase (p<0.05) in VT, PWCFT, and TTE, respectively, for the beta-alanine group, with no changes in the PL (p>0.05). There were no changes for VO2-MAX (p>0.05) in either group. Results of this study indicate that beta-alanine supplementation delays the onset of neuromuscular fatigue (PWCFT) and the ventilatory threshold (VT) at submaximal workloads, and increase in TTE during maximal cycle ergometry performance. However, beta-alanine supplementation did not affect maximal aerobic power (VO2-MAX). In conclusion, beta-alanine supplementation appears to improve submaximal cycle ergometry performance and TTE in young women, perhaps as a result of an increased buffering capacity due to elevated muscle carnosine concentrations.
authors.affiliation: Department of Health and Exercise Science, University of Oklahoma, Norman, OK 73019-6081, USA. jrstout@ou.edu
authors.forename: J R
authors.initials: JR
authors.lastname: Stout
authors.forename: J T
authors.initials: JT
authors.lastname: Cramer
authors.forename: R F
authors.initials: RF
authors.lastname: Zoeller
authors.forename: D
authors.initials: D
authors.lastname: Torok
authors.forename: P
authors.initials: P
authors.lastname: Costa
authors.forename: J R
authors.initials: JR
authors.lastname: Hoffman
authors.forename: R C
authors.initials: RC
authors.lastname: Harris
authors.forename: J
authors.initials: J
authors.lastname: O'Kroy
mesh_terms: D000328:Adult; D002331:Carnitine / Q000378:metabolism; D019587:Dietary Supplements; D005260:Female; D006801:Humans; D005222:Mental Fatigue / Q000378:metabolism / Q000517:prevention & control*; D018763:Muscle Fatigue / Q000187:drug effects*; D018482:Muscle, Skeletal / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects*; D010807:Physical Endurance / Q000187:drug effects*; D015091:beta-Alanine / Q000008:administration & dosage*
chemical_list: D015091:beta-Alanine; D002331:Carnitine