Department of Health and Exercise Science, University of Oklahoma, Norman, OK, U.S.A..
This study examined the effects of 28 days of beta-alanine supplementation on the physical working capacity at fatigue threshold (PWC(FT)), ventilatory threshold (VT), maximal oxygen consumption ([Formula: see text]O(2-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 (CarnoSyntrade mark) 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 PWC(FT), VT, [Formula: see text]O(2-MAX), and TTE. There was a 13.9, 12.6 and 2.5% increase (p < 0.05) in VT, PWC(FT), and TTE, respectively, for the beta-alanine group, with no changes in the PL (p > 0.05). There were no changes for [Formula: see text]O(2-MAX) (p > 0.05) in either group. Results of this study indicate that beta-alanine supplementation delays the onset of neuromuscular fatigue (PWC(FT)) 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 ([Formula: see text]O(2-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.