[Direct and indirect maximum oxygen consumption in sedentary subjects living at a moderate altitude]

In order to compare 1) predicted values of aerobic capacity (VO2Max) and, 2) direct VO2Max reported in the literature for sedentary subjects, direct VO2Max was measured in 27 sedentary males (18-25 years old), residents at 2240 meters (588.5 +/- 1.0 mmHg). To get direct VO2Max, ventilation and expired gases were measured while the subjects performed maximal exercise on a motor treadmill. Predicted VO2Max was estimated from the Astrand and Ryhming nomogram by measuring submaximal heart rate (HR) during a step test protocol. The mean results from the maximal protocol were: HR 194.9 +/- 5.4 beats/min, direct VO2Max 3.15 +/- 0.46 L/min and 47.67 +/- 5.07 ml/min/Kg, absolute and relative to body weight, respectively. From the submaximal protocol, mean HR was 171 +/- 8.3 beats/min and predicted VO2Max 2.50 +/- 0.39 L/min. In spite of a good correlation (r = 0.79) between predicted and direct VO2Max, the predicted values underestimated 20.3 +/- 7.2% direct measurements. Our data point out that 1) indirect measuring of aerobic capacity from the Astrand and Ryhming nomogram is discouraged in sedentary subjects living at moderate altitudes and, 2) in contrast to other author's suggestions, aerobic capacity is not diminished by chronic exposure to moderate hypoxia.