• The effects of 5 days β-alanine supplementation on the velocity and the percentage o2max at the lactate threshold

      Morris, Mike; Fallows, Stephen; Johnson, Matthew (University of Chester, 2010-09)
      Purpose: To assess the effect of 5 days β-alanine supplementation on the velocity and the percentage of O2max ¬¬ (%O2max) at the lactate threshold (Tlac) during treadmill running. Method: Using a double-blind, placebo-control, repeated measures, cross-over design, 6 participants (4 male, 2 female) undertook a Tlac test using a motorised treadmill on 3 separate occasions. For 5 days prior to each test participants ingested β-alanine (50mg∙kg-1∙d-1) or an equal amount of maltodextrin (placebo). Participants performed a control trial where no supplements were ingested prior to testing (control). The velocity, %O2max, O2, blood lactate, heart rate (HR) and RPE at the Tlac were measured during each trial. Significant differences between the 3 trials were assessed via one-way repeated-measures analysis of variance (p ≤ 0.05). Results: There was no significant difference (p = 0.369) in the velocity at the Tlac between the β-alanine (10.17 ± 0.98 km∙h-1), placebo (10.33 ± 1.03 km∙h-1) or the control trials (10.83 ± 1.16km∙h-1). There was no significant difference (p = 0.087) in %O2max at the Tlac between the β-alanine (75.21 ± 6.84%), placebo (75.93 ± 7.32%) or control trials (69.94 ± 7.39). This was coupled with a non significant difference in O2 between the 3 trials (p = 0.103). Blood lactate was not significantly different (p = 0.628) between the β-alanine, placebo and control trials (4.1 ± 1.2, 3.7 ± 1.5 and 4.0 ± 1.8mmol∙L, respectively). HR and RPE at the Tlac were unchanged between trials (p > 0.05). Conclusion: The data suggests that 5 days β-alanine supplementation has no effect on the velocity or %O2max at the Tlac during treadmill running. A five day supplementation period may not be sufficient to augment muscle carnosine concentrations to elicit an ergogenic effect.