Acute Supplementation with Beta-Alanine Improves Performance in Aerobic-Anaerobic Transition Zones in Endurance Athletes

Objective: To determine the acute effect of low and high-dose BA trials on maximal aerobic speed (MAS) in endurance athletes. We hypothesized that high doses of BA have a greater effect than low doses, both compared to baseline. Material and Methods: Twelve male endurance athletes volunteered for the study (age = 21.8 +/- 2.37 years, weight = 69.8 +/- 4.36 kg, height = 174 +/- 5.45 cm, maximal oxygen uptake = 59.6 +/- 3.77 mLO(2)center dot kg(-1)center dot min(-1)). The experimental design applied was randomized cross-over, double-blind. Treatment included three 6-minute run tests (6-MRT), the first as a baseline, then randomized 6-MRT with low (30 mg center dot kg(-1)) and high (45 mg center dot kg(-1)) dose BA trials. The 6-MRTs were separated by 72 hours. The main variable of the study was the distance (m) performed in the 6-MRT. Differences between tests were established through ANOVA and Tukey's multiple comparison tests (p < 0.05). Results: The analysis showed significant differences between baseline and both doses (p < 0.001). No significant differences were observed between low and high-dose BA trials (p > 0.05). Conclusion: Both 30 and 45 mg center dot kg(-1) of BA increased physical performance at maximal aerobic speed in endurance athletes. The acute intake formats described in the present investigation may be helpful for endurance athletes training and competing in aerobic-anaerobic transition zones.