其他摘要：The purpose of the present study was to clarify the cardiorespiratory response to exercise, by comparing the boy's hemodynamic responses to the submaximal and maximal exercises with the adults' responses, and to determine the validity of cardiorespiratory tests for boys. Oxygen intake, heart rate, cardiac output (CO_2 rebreathing technique); stroke volume and arteriovenous oxygen difference were determined in 25 boys and 19 adult men (10.2±0.3 and 21.6±1.8 year-old, respectively) at rest and during maximal exercises on a bicycle ergometer. The boys were applied to the step test and 800m run, too. Maximal oxygen intake for boys was 1.328±0.206l/min or 41.83±4.89ml/kg min, and for the adults 2.785±0.414l/min or 43.40±4.70ml/kg min. For the boys the cardiac output during maximal exercise was 10.01±1.33l/min, stroke volume 51.57±8.00ml, heart rate 194.65±9.68beats/min and arteriovenous oxygen difference 13.31±1.65vol%; for the adults, these values were 18.65±2.87l/min, 98.98±15.76ml, 188.32±7.25beats/min and 15.15±1.70vol%, respectively. All values obtained for the boys were significantly different (p < 0.01) from those found in the adults. The correlation between maiximal oxygen intake and hemodynamic responses to the maximal exercise described above was found to be statistically significant. The results in PWC_<170> was significantly correlated to maximal oxygen intake, maximal cardiac output, maximal stroke volume and step test score. The 800m run had the significant correlation only to maximal oxygen intake per kg of the body weight. But the step test score was not significantly correlated to the cardiorespiratory capacities. From the present results above mentioned, it was suggested that the remarkable increase in the adults' maximal oxygen intake from resting oxigen intake would be more dependent on the increase in the heart rate and arteriovenous oxygen difference. The same values of maximal oxygen intake per body weight observed in boys and adults were caused by the same values of maximal stroke volume per body weight in boys and adults and by higher maximal heart rate and smaller maximal arteriovenous oxygen difference in boys. The correlation coefficient between PWC_<170> and maximal oxygen intake per body weight was not significant (r=0.23). The highest valid correlation (r=0.71) was obtained between maximal oxygen intake per body weight and PWC<170> per body weight. The performance of 800m run was correlated to maximal oxygen intake per body weight as r=-0.57. But the step test score did not show valid relationship with cardiovascular functions.
