TY - JOUR
T1 - Pulmonary gas exchange during exercise in athletes I. Ventilation- perfusion mismatch and diffusion limitation
AU - Hopkins, S. R.
AU - McKenzie, D. C.
AU - Schoene, Robert Blair
AU - Glenny, R. W.
AU - Robertson, H. T.
PY - 1994/1/1
Y1 - 1994/1/1
N2 - To investigate pulmonary gas exchange during exercise in athletes, 10 high aerobic capacity athletes (maximal aerobic capacity = 5.15 ± 0.52 l/min) underwent testing on a cycle ergometer at rest, 150 W, 300 W, and maximal exercise (372 ± 22 W) while trace amounts of six inert gases were infused intravenously. Arterial blood samples, mixed expired gas samples, and metabolic data were obtained. Indexes of ventilation-perfusion (V̇A/Q̇) mismatch were calculated by the multiple inert gas elimination technique. The alveolar-arterial difference for O2 (AaDO2) was predicted from the inert gas model on the basis of the calculated V̇A/Q̇ mismatch V̇A/Q̇ heterogeneity increased significantly with exercise and was predicted to increase the AaDO2 by > 17 Torr during heavy and maximal exercise. The observed AaDO2 increased significantly more than that predicted by the inert gas technique during maximal exercise (10 ± 10 Torr). These data suggest that this population develops diffusion limitation during maximal exercise, but V̇A/Q̇ mismatch is the most important contributor (>60%) to the wide AaDO2 observed.
AB - To investigate pulmonary gas exchange during exercise in athletes, 10 high aerobic capacity athletes (maximal aerobic capacity = 5.15 ± 0.52 l/min) underwent testing on a cycle ergometer at rest, 150 W, 300 W, and maximal exercise (372 ± 22 W) while trace amounts of six inert gases were infused intravenously. Arterial blood samples, mixed expired gas samples, and metabolic data were obtained. Indexes of ventilation-perfusion (V̇A/Q̇) mismatch were calculated by the multiple inert gas elimination technique. The alveolar-arterial difference for O2 (AaDO2) was predicted from the inert gas model on the basis of the calculated V̇A/Q̇ mismatch V̇A/Q̇ heterogeneity increased significantly with exercise and was predicted to increase the AaDO2 by > 17 Torr during heavy and maximal exercise. The observed AaDO2 increased significantly more than that predicted by the inert gas technique during maximal exercise (10 ± 10 Torr). These data suggest that this population develops diffusion limitation during maximal exercise, but V̇A/Q̇ mismatch is the most important contributor (>60%) to the wide AaDO2 observed.
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U2 - 10.1152/jappl.1994.77.2.912
DO - 10.1152/jappl.1994.77.2.912
M3 - Article
C2 - 8002547
AN - SCOPUS:0028145801
VL - 77
SP - 912
EP - 917
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 2
ER -