title: Determinant factors of the decrease in aerobic performance in moderate acute hypoxia in women endurance athletes.
abstract: The purpose of this study was to evaluate the limiting factors of maximal aerobic performance in endurance trained (TW) and sedentary (UW) women. Subjects performed four incremental tests on a cycle ergometer at sea level and in normobaric hypoxia corresponding to 1000, 2500 and 4500 m. Maximal oxygen uptake decrement (Delta VO2 max) was larger in TW at each altitude. Maximal heart rate and ventilation decreased at 4500 m in TW. Maximal cardiac output remained unchanged. In both groups, arterialized oxygen saturation (Sa'O2 max) decreased at and above 2500 m and maximal O2 transport (QaO2 max) decreased from 1000 m. At 4500 m, there was no more difference in QaO2 max between TW and UW. Mixed venous O2 pressure (PvO2 max) was lower and O2 extraction (O2ERmax) greater in TW at each altitude. The primary determinant factor of VO2 max decrement in moderate acute hypoxia in trained and untrained women is a reduced maximal O2 transport that cannot be compensate by tissue O2 extraction.
authors.affiliation: Université Paris 13, Laboratoire Réponses cellulaires et fonctionnelles à l'hypoxie, EA2363, ARPE, 74 rue Marcel Cachin, 93017 Bobigny Cedex, France. pascal.mollard@laposte.net
authors.forename: Pascal
authors.initials: P
authors.lastname: Mollard
authors.forename: Xavier
authors.initials: X
authors.lastname: Woorons
authors.forename: Muriel
authors.initials: M
authors.lastname: Letournel
authors.forename: Christine
authors.initials: C
authors.lastname: Lamberto
authors.forename: Fabrice
authors.initials: F
authors.lastname: Favret
authors.forename: Aurélien
authors.initials: A
authors.lastname: Pichon
authors.forename: Michèle
authors.initials: M
authors.lastname: Beaudry
authors.forename: Jean-Paul
authors.initials: JP
authors.lastname: Richalet
mesh_terms: D000293:Adolescent; D000328:Adult; D000531:Altitude; D015308:Anaerobic Threshold / Q000502:physiology; D000704:Analysis of Variance; D002302:Cardiac Output / Q000502:physiology; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D010809:Physical Fitness; D011659:Pulmonary Gas Exchange / Q000502:physiology; D013177:Sports / Q000502:physiology*
chemical_list: D010100:Oxygen