Operation Everest III: role of plasma volume expansion on VO2max during prolonged high-altitude exposure

• Published in: Journal of applied physiology (1985) 2000-07, Vol.89 (1), p.29-37
• Main Authors: Robach, Paul, Dechaux, Michele, Jarrot, Sebastien, Vaysse, Jenny, Schneider, Jean-Christophe, Mason, Nicholas P, Herry, Jean-Pierre, Gardette, Bernard, Richalet, Jean-Paul
• Format: Article
• Language: English
• Subjects: Altitude; Applied physiology; Biological and medical sciences; Blood; Human physiology applied to population studies and life conditions. Human ecophysiology; Medical sciences; Oxygen; Plasma; Transports. Aerospace. Diving. Altitude
• ISSN: 8750-7587; 1522-1601

1  Ecole Nationale de Ski et d'alpinisme, 74401 Chamonix; 2  Association pour la Recherche en Physiologie de l'Environnement, 93017 Bobigny; 3  Laboratoire de Physiologie, hôpital Necker, 75015 Paris; 4  Laboratoire de Biochimie, hôpital Jean Verdier, 93140 Bondy; and 5  COMEX S.A., 13275 Marseille, France We hypothesize that plasma volume decrease ( PV) induced by high-altitude (HA) exposure and intense exercise is involved in the limitation of maximal O 2 uptake ( O 2 max ) at HA. Eight male subjects were decompressed for 31 days in a hypobaric chamber to the barometric equivalent of Mt. Everest (8,848 m). Maximal exercise was performed with and without plasma volume expansion (PVX, 219-292 ml) during exercise, at sea level (SL), at HA (370   mmHg, equivalent to 6,000 m after 10-12 days) and after return to SL (RSL, 1-3 days). Plasma volume (PV) was determined at rest at SL, HA, and RSL by Evans blue dilution. PV was decreased by 26% ( P