title: Sodium bicarbonate ingestion does not attenuate the VO2 slow component during constant-load exercise.
abstract: We examined the effects of sodium bicarbonate ingestion on the VO2 slow component during constant-load exercise. Twelve physically active males performed two 30-min cycling trials at an intensity above the lactate threshold. Subjects ingested either sodium bicarbonate (BIC) or placebo (PLC) in a randomized, counterbalanced order. Arterialized capillary blood samples were analyzed for pH, bicarbonate concentration ([HCO3-]), and lactate concentration ([La]). Expired gas samples were analyzed for oxygen consumption (VO2). The VO2 slow component was defined as the change in VO2 from Minutes 3 and 4 to Minutes 28 and 29. Values for pH and [HCO3-] were significantly higher for BIC compared to PLC. There was no significant difference in [La] between conditions. For both conditions there was a significant time effect for VO2 during exercise; however, no significant difference was observed between BIC and PLC. While extracellular acid-base measures were altered during the BIC trial, sodium bicarbonate ingestion did not attenuate the VO2 slow component during constant-load exercise.
authors.affiliation: Department of Health, Sport, and Exercise Sciences, University of Kansas, Lawrence 66045, USA.
authors.forename: K L
authors.initials: KL
authors.lastname: Heck
authors.forename: J A
authors.initials: JA
authors.lastname: Potteiger
authors.forename: K L
authors.initials: KL
authors.lastname: Nau
authors.forename: J M
authors.initials: JM
authors.lastname: Schroeder
mesh_terms: D000328:Adult; D001774:Blood Chemical Analysis; D015331:Cohort Studies; D018592:Cross-Over Studies; D004435:Eating / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000097:blood / Q000378:metabolism; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D017693:Sodium Bicarbonate / Q000008:administration & dosage* / Q000097:blood / Q000378:metabolism; D013997:Time Factors
chemical_list: D019344:Lactic Acid; D017693:Sodium Bicarbonate