Effect of β-alanine plus sodium bicarbonate on high-intensity cycling capacity

• Published in: Medicine and science in sports and exercise Vol. 43; no. 10; p. 1972
• Main Authors: Sale, Craig, Saunders, Bryan, Hudson, Sean, Wise, John A, Harris, Roger C, Sunderland, Caroline D
• Format: Journal Article
• Language: English
• Published: United States 01.10.2011
• Subjects: Adult; beta-Alanine - administration & dosage; Bicycling - psychology; Cross-Over Studies; Dietary Supplements; Exercise Test; Humans; Hydrogen-Ion Concentration - drug effects; Lactic Acid - blood; Male; Physical Endurance - drug effects; Polysaccharides - administration & dosage; Sodium Bicarbonate - administration & dosage; Sodium Bicarbonate - blood; Young Adult
• ISSN: 1530-0315
• DOI: 10.1249/MSS.0b013e3182188501

We examined the effect of β-alanine supplementation plus sodium bicarbonate on high-intensity cycling capacity. 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 β-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 CCT(110%) 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. 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. Results show that BA improved high-intensity cycling capacity. However, despite a 6-s (∼4%) increase in TTE with the addition of SB, this did not reach statistical significance, but magnitude-based inferences suggested a ∼70% probability of a meaningful positive difference.