Human ventilatory responsiveness to hypoxia is unrelated to maximal aerobic capacity

1 School of Human Kinetics, and 2 Faculty of Medicine, The University of British Columbia, Vancouver, British Columbia, Canada Submitted 12 September 2005 ; accepted in final form 4 January 2006 Ventilatory responsiveness to hypoxia (HVR) has been reported to be different between highly trained endurance athletes and healthy sedentary controls. However, a linkage between aerobic capacity and HVR has not been a universal finding. The purpose of this study was to examine the relationship between HVR and maximal oxygen consumption ( O 2 max ) in healthy men with a wide range of aerobic capacities. Subjects performed a HVR test followed by an incremental cycle test to exhaustion. Participants were classified according to their maximal aerobic capacity. Those with a O 2 max of 60 ml·kg –1 ·min –1 were considered highly trained ( n = 13); those with a O 2 max of 50–60 ml·kg –1 ·min –1 were considered moderately-trained ( n = 18); and those with a O 2 max of 0.05), and the HVR values were variable within each group (range: untrained = 0.28–1.61, moderately trained = 0.23–2.39, and highly trained = 0.08–1.73 l·min·%arterial O 2 saturation –1 ). The relationship between HVR and O 2 max was not statistically significant ( r = –0.1723; P > 0.05). HVR was also unrelated to maximal minute ventilation and ventilatory equivalents for O 2 and CO 2 . We found that a spectrum of hypoxic ventilatory control is present in well-trained endurance athletes and moderately and untrained men. We interpret these observations to mean that other factors are more important in determining hypoxic ventilatory control than physical conditioning per se. control of breathing; exercise; hypoxic ventilatory response Address for reprint requests and other correspondence: W. Sheel, Health and Integrative Physiology Laboratory, School of Human Kinetics, The Univ. of British Columbia, 210-6081 Univ. Blvd., Vancouver, BC, Canada V6T 1Z1 (e-mail: bill.sheel{at}ubc.ca )