Effect of β-Alanine Plus Sodium Bicarbonate on High-Intensity Cycling Capacity

SALE, C., B. SAUNDERS, S. HUDSON, J. A. WISE, R. C. HARRIS, and C. D. SUNDERLAND. Effect of beta-Alanine Plus Sodium Bicarbonate on High-Intensity Cycling Capacity. Med. Sci. Sports Exerc., Vol. 43, No. 10, pp. 1972-1978, 2011. Purpose: We examined the effect of beta-alanine supplementation plus sodium bicarbonate on high-intensity cycling capacity. Methods: Twenty males (age = 25 +/- 5 yr, height = 1.79 +/- 0.06 m, body mass = 80.0 +/- 10.3 kg) were assigned to either a placebo (P) or a beta-alanine (BA; 6.4 g.d(-1) for 4 wk) group based on power max, completing four cycling capacity tests at 110% of power max (CCT110%) to determine time to exhaustion (TTE) and total work done. A CCT110% was performed twice (habituation and baseline) before supplementation (with maltodextrin [MD]) and twice after supplementation (with MD and with sodium bicarbonate [SB]), using a crossover design with 2 d of rest between trials, creating four study conditions (PMD, PSB, BAMD, and BASB). Blood pH, Lactate, bicarbonate and base excess were determined at baseline, before exercise, immediately after exercise, and 5 min after exercise. Data were analyzed using repeated-measures ANOVA. Results: TTE was increased in all conditions after supplementation (+1.6% PMD, +6.5% PSB, +12.1% BAMD, and +16.2% BASB). Both BAMD and BASB resulted in significantly improved TTE compared with that before supplementation (P <= 0.01). Although further increases in TTE (4.1%) were shown in BASB compared with BAMD, these differences were not significant (P = 0.74). Differences in total work done were similar to those of TTE. Blood bicarbonate concentrations were significantly (P <= 0.001) elevated before exercise in PSB and BASB but not in PMD or BAMD. Blood lactate concentrations were significantly elevated after exercise, remaining elevated after 5 min of recovery (P <= 0.001) and were highest in PSB and BASB. Conclusions: Results show that BA improved high-intensity cycling capacity. However, despite a 6-s (similar to 4%) increase in TTE with the addition of SB, this did not reach statistical significance, but magnitude-based inferences suggested a similar to 70% probability of a meaningful positive difference.