Bronchial Responsiveness and Lung Function in a Cohort of College Students of Medical Technology Ⅳ. Evaluation of Gas Exchange during Exercise Test

An integrative cardiopulmonary exercise test is often used to assess a subject’s exercise capacity and thus can detect any existing impaired physical activity. To investigate the exercise performance of normal Chinese adults, gas exchange and ventilatory variables were measured with a cycle ergometer in 26 college students. Measurements were made during an exercise protocol in which the work rate was increased in a stepwise manner each minute. Our results show that the maximal work rate tolerated in men was 221 ± 20 watts. The values for maximal oxygen consumption ( O2 ) were 2225 ± 211 ml/min and 1673 ± 235 ml/min for men and women, respectively, and both corresponding to 7 times their baseline values. Men also had a significantly higher maximal minute ventilation than did women . However, there were no appreciable differences in heart rate, respiratory rate and respiratory quotient ( CO2/ O2, RQ) from the final minute of maximal exercise between the sexes. These findings suggest that during maximal exercise, breathing pattern is basically independent of gender, and the greater O2 and CO2 values observed in men can be partly attributed to a much larger tidal volume than that of women.