title: Effect of combined β-alanine and sodium bicarbonate supplementation on cycling performance.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effects of 28 d of β-alanine supplementation on 4-min cycling time trial performance and to determine whether there was an additive effect of combined β-alanine and sodium bicarbonate (NaHCO3) supplementation on high-intensity cycling performance.
  
  
  METHODS
  Fourteen highly trained cyclists (mean ± SD: age = 25.4 ± 7.2 yr, mass = 71.1 ± 7.1 kg, V˙O(2max) = 66.6 ± 5.7 mL·kg·min) supplemented for 28 d with β-alanine (65 mg·kg body mass each day) or placebo. A maximal 4-min bout of cycling was performed before supplementation (baseline) and twice after supplementation: after ingestion of NaHCO3 (300 mg·kg body mass) and ingestion of a placebo using a randomized crossover design with 2 d between trials. Blood pH and HCO3 concentration were determined before loading (postsupplementation trials) and at pretest and posttest.
  
  
  RESULTS
  In the acute NaHCO3 loading trials, blood pH and HCO3 were elevated from before loading to pretest, and the magnitude of the change in HCO3 from pretest to posttest was significantly greater compared with the acute placebo loading trial (P < 0.001). Average power output in the 4-min cycling performance trial was increased in placebo + NaHCO3 (+3.1% ± 1.8%) and β-alanine + NaHCO3 (+3.3% ± 3.0%) compared with baseline (P < 0.05). β-alanine + placebo did not significantly improve average power output compared with 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 4-min cycling performance; however, there may be a small meaningful improvement in performance. Acute NaHCO3 supplementation significantly improved 4-min cycling performance. There seemed to be a minimal additive effect of combined β-alanine and NaHCO3 supplementation.
authors.affiliation: School of Human Life Sciences, University of Tasmania, Launceston, Tasmania, Australia. phillipb@utas.edu.au
authors.forename: Phillip M
authors.initials: PM
authors.lastname: Bellinger
authors.forename: Samuel T
authors.initials: ST
authors.lastname: Howe
authors.forename: Cecilia M
authors.initials: CM
authors.lastname: Shing
authors.forename: James W
authors.initials: JW
authors.lastname: Fell
mesh_terms: D000328:Adult; D054874:Athletic Performance / Q000502:physiology*; D001639:Bicarbonates / Q000097:blood; D001642:Bicycling / Q000502:physiology*; D019587:Dietary Supplements; D005080:Exercise Test; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood; D008297:Male; D010807:Physical Endurance / Q000187:drug effects*; D017693:Sodium Bicarbonate / Q000494:pharmacology*; D055815:Young Adult; D015091:beta-Alanine / Q000494:pharmacology*
chemical_list: D001639:Bicarbonates; D015091:beta-Alanine; D019344:Lactic Acid; D017693:Sodium Bicarbonate