Abstract

In search for a method of evaluating the cardiopulmonary function. 74 male and 33 female volunteers ages 18~25 were subjected to this study. The subjects walked on a treadmill at speed of 2,4,6 and 8km/hr with 0,5,10,15,20 and 25% grade of inclination, respectively, for a measurement of heart rate and oxygen-pulse. Heart rate was measured every 5 seconds at resting state and during walking by telemetric method using Heart Checker 108 System (Senoh Co., Japan). Oxygen concentration was measured by Douglas bag method collecting expired air for 5 minutes at rest, and for 2 minutes at the end of each walking exercise. Oxygen concentration in an expired air was analyzed with Orzat gas analyzer and expressed in terms of STPD. Oxygen-pulse was defined as an amount of oxygen consumed at every heart at a cellular level. The followings were the results obtained from this study. 1. Mean values of oxygen-pulse at resting state was 3.1+/-0.11 ml/beat in male and 2.5+/-0.87 ml/beat in female, respectively. 2. Mean values of oxygen-pulse during treadmill walking were increased in proportion with the load of exercise, namely, the speed and grade of inclination, from minimum of 7.1 ml/beat upto maximum of 18.2 ml/beat in male and from minimum of 4.2 ml/beat upto maximum of 12.7 ml/beat in female. 3. Both linear and logarithmic regressional relationships between oxygen-pulse and speed of walking and grade of inclination were observed in both sexes. Predicted values of oxygen-pulse by logarithmic regressional formula on speed and on grade of inclination were better coincided with the measured values than those predicted by the linear regressional formula.