title: Effects of sodium bicarbonate, caffeine, and their combination on repeated 200-m freestyle performance.
abstract: The purpose of this study was to investigate the effects of sodium bicarbonate (NaHCO(3)), caffeine, and their combination on repeated 200-m freestyle performance. Six elite male freestyle swimmers ingested NaHCO(3) (0.3 g/kg; B), caffeine (6.2 +/- 0.3 mg/kg; C), a combination of both (B+C), and placebo (P) on 4 separate occasions before completing 2 maximal 200-m freestyle time trials (TT1 and TT2) separated by 30 min. No significant differences (p = .06) were observed for performance in TT1 (B 2:03.01 +/- 0:03.68 min, C 2:02.42 +/- 0:03.17 min, B+C 2:01.69 +/- 0:03.19 min, P 2:03.77 +/- 0:03.21 min) or TT2 (B 2:02.62 +/- 0:04.16 min, C 2:03.90 +/- 0:03.58 min, B+C 2:01.70 +/- 0:02.84 min, P 2:04.22 +/- 0:03.75 min). The drop-off in performance time from TT1 to TT2, however, was significantly greater when C was ingested than with B (-1.5%, p = .002) or B+C (-1.2%, p = .024). This is likely because of the lower blood pH and slower recovery of blood HCO(3) post-TT1 after C ingestion. These findings suggest that the ergogenic benefit of taking C alone for repeated 200-m swimming performance appears limited. When combined with NaHCO(3), however, its negative impact on repeated maximal exercise performance is reversed.
authors.affiliation: Department of Sport Science, Victorian Inst of Sport, Melbourne, Victoria, Australia.
authors.forename: Cathryn L
authors.initials: CL
authors.lastname: Pruscino
authors.forename: Megan L R
authors.initials: ML
authors.lastname: Ross
authors.forename: John R
authors.initials: JR
authors.lastname: Gregory
authors.forename: Bernard
authors.initials: B
authors.lastname: Savage
authors.forename: Troy R
authors.initials: TR
authors.lastname: Flanagan
mesh_terms: D000284:Administration, Oral; D000328:Adult; D001774:Blood Chemical Analysis / Q000379:methods*; D002110:Caffeine / Q000378:metabolism / Q000494:pharmacology*; D018592:Cross-Over Studies; D004338:Drug Combinations; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007773:Lactates / Q000097:blood; D008297:Male; D017693:Sodium Bicarbonate / Q000378:metabolism / Q000494:pharmacology*; D013550:Swimming / Q000502:physiology*; D013647:Task Performance and Analysis
chemical_list: D004338:Drug Combinations; D007773:Lactates; D002110:Caffeine; D017693:Sodium Bicarbonate