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The effect of combined β-Alanine and NaHCO3 supplementation on cycling performance
Purpose: The purpose of this study was to investigate the effects of 28-days of β-alanine supplementation on four minute cycling time trial performance and to determine if there was an additive effect of combined β-alanine and sodium bicarbonate (NaHCO3) supplementation on high-intensity cycling performance.
Method: Fourteen highly-trained cyclists (mean ± SD; age = 25.4 ± 7.2 yr; mass = 71.1 ± 7.1 kg; V̇O2max = 66.6 ± 5.7 mL.kg-1.min-1) supplemented for 28-days with β-alanine (65 mg.kg-1 body mass each day) or placebo. A maximal four minute bout of cycling was performed pre-supplementation (baseline) and twice post-supplementation: following ingestion of NaHCO3 (300 mg.kg-1 body mass), and ingestion of a placebo using a randomized crossover design with two days between trials. Blood pH and HCO3- concentration were determined pre-loading (post-supplementation trials), pre-test and post-test.
Results: In the acute NaHCO3 loading trials blood pH and HCO3- were elevated from pre-loading to pre-test and the magnitude of the change in HCO3- from pre-test to post-test was significantly greater compared to the acute placebo loading trial (P < 0.001). Average power output in the four minute cycling performance trial was increased in placebo + NaHCO3 (+3.1% ± 1.8%) and β-alanine + NaHCO3 (+3.3% ± 3.0%) compared to baseline (P < 0.05). β-alanine + placebo did not significantly improve average power output compared to baseline (+1.6% ± 1.7%; P = 0.20), however, magnitude based inferences demonstrated that β-alanine+placebo was associated with a 37% likelihood of producing average power improvements.
Conclusions: In trained cyclists β-alanine supplementation did not significantly improve four minute cycling performance; however, there may be a small meaningful improvement in performance. Acute NaHCO3 supplementation significantly improved four minute cycling performance. There appeared to be minimal additive effect of combined β-alanine and NaHCO3 supplementation.
University of Tasmania
Publication titleMedicine & Science in Sports & Exercise
Department/SchoolSchool of Health Sciences
PublisherLippincott Williams & Wilkins
Place of publicationUSA
Rights statementCopyright 2012 by the American College of Sports Medicine