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This study is designed to obtain date for the assessment of maximal aerobic work capacity of young male adult. College students were as subjects, and heart rate, oxygen uptake and energy cost were measured on 75 volunteers during treadmill walking at speed of 2, 4, 6 and 8km/hr with different grade of inclination from level (0%) to 25%. Individual maximal oxygen uptake was predicted using Astrand and Ryhming’s nomogram from the data obtained during the treadmill walking, and compared with the measured value on 28 subjects plotting on the linear regression of heart rate on oxygen uptake. The results obtained were as follows: 1. Maximal heart rate was 189.5±4.69 beat/min in average which was 2.4 times as fast as those at resting state. Average maximal oxygen uptake and maximal energy cost were 51.4±5.69ml/kg/min, and 15.2±1.36kcal/kg/hr, respectively. These values were accounted for 14 times increase in both average oxygen uptake of 3.73±1.23ml/kg/min, and average energy cost of 1.08±0.38kcal/kg/hr at resting state. 2. During walking on level treadmill at speed of 2, 4, 6, and 8km/hr, respective average values of heart rate were 92.8±10.02, 98.1±11.46, 120.8±13.3, and 159.8±14.57 beat/min, of oxygen uptake 9.7±2.04, 13.4±2.53, 20.4±2.68 and 34.0±7.54ml/kg/min, and of energy cost 2.0±0.52, 3.9±0.70, 6.0±0.78 and 10.1±2.26 kacl/kg/hr. 3. Rates of increase in heart rate, oxygen uptake and energy cost were remarkable in comparison with the increase in speed of walking with less tan 15% grade of inclination, and the rate of increase was proportional to the increase in speed of walking with 15% grade of inclination. 4. Close association was observed between oxygen uptake(ml/min) and energy cost(kcal/hr) with coefficient of correlation r=0.9801(p<0.01). Linear regression of energy cost on oxygen uptake was expressed as Y=0.290 X+14.7 and standard deviation of the estimate was S_y/x=±51.9kcal/hr. This indicated that the energy cost per liter of oxygen consumed was equivalent to 5.08kacl/min of energy cost. 5. Linear regression of heart rate(beat/min) on oxygen uptake(X_1:ml.kg/min) and energy cost(X_2: kcal/kg/hr) were expressed as follows: Y=2.29X_1+77.9(S_y/x=±15.6beat/min) Y=7.84X_2+77.7(S_y/x=±15.4beat/min) with coefficient of correlation r=0.8884(p<0.01) for the former and r=0.8866(p<0.01) for the latter. 6. maximal aerobic work capacity of an individual could be assessed by the regression equation of heart rate(beat/min) on oxygen uptake(X: ml/min). Heart rate for persons with better maximal aerobic work capacity showed the slower heart rate with the same amount of oxygen uptake. It was suggested that in predicting the heart rate for the assessment of maximal work capacity, oxygen uptake during submaximal work should exceed at least 50% of the maximal value(3,500ml/min).
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