Claire Thomas1,2, Rémi Delfour-Peyrethon3, David J Bishop4, Stéphane Perrey5, Pierre-Marie Leprêtre6, Sylvain Dorel7, Christine Hanon3. 1. French National Institute of Sports (INSEP), 11 Tremblay Avenue, 75012, Paris, France. claire.thomas@univ-evry.fr. 2. STAPS Department, University of Evry Val d'Essonne, François Mitterrand Boulevard, 91025, Evry, France. claire.thomas@univ-evry.fr. 3. French National Institute of Sports (INSEP), 11 Tremblay Avenue, 75012, Paris, France. 4. Institute of Sport, Exercise and Active Living (ISEAL), College of Sport and Exercise Science, Victoria University, Melbourne, Australia. 5. EuroMov: Movement to Health, University of Montpellier, Montpellier, France. 6. Laboratory "Adaptations physiologiques à l'exercice et réadaptation à l'effort" (EA-3300), University of Picardie Jules Verne, UFR-STAPS, 80025, Amiens Cedex, France. 7. Laboratory "Motricité, Interactions, Performance" (EA 4334), University of Nantes, 44000, Nantes, France.
Abstract
PURPOSE: This study determined the effects of pre-exercise sodium bicarbonate ingestion (ALK) on changes in oxygen uptake (VO2) at the end of a supramaximal exercise test (SXT). METHODS: Eleven well-trained cyclists completed a 70-s all-out cycling effort, in double-blind trials, after oral ingestion of either 0.3 g kg(-1) of sodium bicarbonate (NaHCO3) or 0.2 g kg(-1) body mass of calcium carbonate (PLA). Blood samples were taken to assess changes in acid-base balance before the start of the supramaximal exercise, and 0, 5 and 8 min after the exercise; ventilatory parameters were also measured at rest and during the SXT. RESULTS: At the end of the PLA trial, which induced mild acidosis (blood pH = 7.20), subjects presented a significant decrease in VO2 (P < 0.05), which was related to the amplitude of the decrease in minute ventilation (VE) during the SXT (r = 0.70, P < 0.01, n = 11). Pre-exercise metabolic alkalosis significantly prevented the exercise-induced decrease in VO2 in eleven well-trained participants (PLA:12.5 ± 2.1 % and ALK: 4.9 ± 0.9 %, P < 0.05) and the decrease in mean power output was significantly less pronounced in ALK (P < 0.05). Changes in the VO2 decrease between PLA and ALK trials were positively related to changes in the VE decrease (r = 0.74, P < 0.001), but not to changes in power output (P > 0.05). CONCLUSIONS:Pre-exercise alkalosis counteracted the VO2 decrease related to mild acidosis, potentially as a result of changes in VE and in muscle acid-base status during the all-out supramaximal exercise.
RCT Entities:
PURPOSE: This study determined the effects of pre-exercise sodium bicarbonate ingestion (ALK) on changes in oxygen uptake (VO2) at the end of a supramaximal exercise test (SXT). METHODS: Eleven well-trained cyclists completed a 70-s all-out cycling effort, in double-blind trials, after oral ingestion of either 0.3 g kg(-1) of sodium bicarbonate (NaHCO3) or 0.2 g kg(-1) body mass of calcium carbonate (PLA). Blood samples were taken to assess changes in acid-base balance before the start of the supramaximal exercise, and 0, 5 and 8 min after the exercise; ventilatory parameters were also measured at rest and during the SXT. RESULTS: At the end of the PLA trial, which induced mild acidosis (blood pH = 7.20), subjects presented a significant decrease in VO2 (P < 0.05), which was related to the amplitude of the decrease in minute ventilation (VE) during the SXT (r = 0.70, P < 0.01, n = 11). Pre-exercise metabolic alkalosis significantly prevented the exercise-induced decrease in VO2 in eleven well-trained participants (PLA:12.5 ± 2.1 % and ALK: 4.9 ± 0.9 %, P < 0.05) and the decrease in mean power output was significantly less pronounced in ALK (P < 0.05). Changes in the VO2 decrease between PLA and ALK trials were positively related to changes in the VE decrease (r = 0.74, P < 0.001), but not to changes in power output (P > 0.05). CONCLUSIONS: Pre-exercise alkalosis counteracted the VO2 decrease related to mild acidosis, potentially as a result of changes in VE and in muscle acid-base status during the all-out supramaximal exercise.
Authors: M G Hollidge-Horvat; M L Parolin; D Wong; N L Jones; G J Heigenhauser Journal: Am J Physiol Endocrinol Metab Date: 2000-02 Impact factor: 4.310
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Authors: Krzysztof Durkalec-Michalski; Emilia E Zawieja; Tomasz Podgórski; Igor Łoniewski; Bogna E Zawieja; Marta Warzybok; Jan Jeszka Journal: PLoS One Date: 2018-05-17 Impact factor: 3.240