'Oxygen uptake efficiency slope' in trained and untrained subjects exposed to hypoxia.
We assessed the ability of the oxygen uptake efficiency slope, whether calculated on 100 and 80% of maximal exercise test duration (OUES(100) and OUES(80)), to identify the change in cardiorespiratory capacities in response to hypoxia in subjects with a broad range of V(O2 peak). Four maximal exercise tests were performed in trained (T) and untrained subjects (UT) in normoxia and at 1000, 2500 and 4500 m. The mean reductions in maximal exercise capacities at 4500 m were the same in T subjects for V(O2 peak) (-30%), OUES(80) (-26%) and OUES(100) (-26%) whereas in UT subjects only OUES(100) (-14%), but not OUES(80) (-20%), was lower compared with V(O2 peak) (-21%, p<0.05). OUES(100) and OUES(80) were correlated with V(O2 peak) and the ventilatory anaerobic threshold in both groups. Multiple regression analyses showed that V(O2 peak), OUES(100) and OUES(80) were significantly linked to O(2) arterial-venous difference. The OUES(80) could be considered as an interesting sub-maximal index of cardiorespiratory fitness in normal or hypoxemic subjects unable to reach V(O2 peak).
Mollard
Pascal
P
Université Paris 13, UFR SMBH, STAPS, Laboratoire Réponses Cellulaires et Fonctionnelles à l'hypoxie, UPRES EA 2363, 74 rue Marcel Cachin, 93017 Bobigny Cedex, France.
Woorons
Xavier
X
Antoine-Jonville
Sophie
S
Jutand
Luce
L
Richalet
Jean Paul
JP
Favret
Fabrice
F
Pichon
Aurélien
A
D000222:Adaptation, Physiological; D000328:Adult; D002320:Cardiovascular Physiological Phenomena; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D006801:Humans; D000860:Hypoxia / Q000097:blood*; D008297:Male; D010100:Oxygen / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology*; D010809:Physical Fitness / Q000502:physiology*; D012016:Reference Values
D010100:Oxygen