title: Effect of hyperoxia on maximal O2 uptake in exercise-induced arterial hypoxaemic subjects.
abstract: This study focuses on the effect of hyperoxia on maximal oxygen uptake VO2max and maximal power (Pmax) in subjects exhibiting exercise-induced arterial hypoxemia (EIH) at sea level. Sixteen competing male cyclists VO2max > 60 ml.min(-1).kg(-1)) performed exhaustive ramp exercise (cycle-ergometer) under normoxia and moderate hyperoxia (FIO2 = 30%). After the normoxic trial, the subjects were divided into those demonstrating EIH during exercise [arterial O2 desaturation (delta SaO2) >5%; n = 9] and those who did not (n = 7). Under hyperoxia, SaO2 raised and the increase was greater for the EIH than for the non-EIH group (P<0.001). VO2max improved for both groups and to a greater extent for EIH (12.8 +/- 5.7% vs. 4.2 +/- 4.6%, P<0.01; mean+/-SD) and the increase was correlated to the gain in SaO2 for all subjects (r = 0.71, P<0.01). Pmax improved by 3.3 +/- 3.3% (P<0.01) regardless of the group. These data suggest that pulmonary gas exchange contributes to a limitation in VO2max and power for especially EIH subjects.
authors.affiliation: Unité de recherche Physiologie et physiopathologie de l'Exercice et Handicap, Université Jean Monnet, CHU de Saint Etienne, Hôpital Bellevue, Médecine du Sport et Myologie, Saint-Etienne, France. olivier.grataloup@univ-st-etienne.fr
authors.forename: Olivier
authors.initials: O
authors.lastname: Grataloup
authors.forename: Fabrice
authors.initials: F
authors.lastname: Prieur
authors.forename: Thierry
authors.initials: T
authors.lastname: Busso
authors.forename: Josiane
authors.initials: J
authors.lastname: Castells
authors.forename: François B
authors.initials: FB
authors.lastname: Favier
authors.forename: Christian
authors.initials: C
authors.lastname: Denis
authors.forename: Henri
authors.initials: H
authors.lastname: Benoit
mesh_terms: D000328:Adult; D001642:Bicycling; D015444:Exercise; D026241:Exercise Movement Techniques / Q000009:adverse effects*; D006801:Humans; D018496:Hyperoxia / Q000150:complications* / Q000503:physiopathology*; D000860:Hypoxia / Q000209:etiology* / Q000503:physiopathology*; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption; D010807:Physical Endurance
chemical_list: D010100:Oxygen