THE INFLUENCE OF GRADED EXERCISES ON THE OXYGEN CONSUMPTION, PULMONARY VENTILATION AND HEART RATE OF YOUNG AND ELDERLY MEN

Abstract

1. The effects of exercise were compared on two groups of healthy men, the one aged 20–30 years and the other aged 55–65. There were 12 men in each group. 2. Four grades of exercise were used, two on an arm ergometer and two on a treadmill. The first arm exercise was light in nature, involving an average energy expenditure of just over 4 kcal/min. The second arm exercise and the first treadmill exercise, walking on the level at 3·7 m.p.h., were of moderate severity. The second degree on the treadmill, walking on the level at 4·3 m.p.h., was more strenuous. 3. Oxygen consumption, pulmonary ventilation and heart rates were recorded during the exercises, and the heart rate and blood pressure were followed during the first 10 min. after the work. 4. There was no significant difference in these measurements, nor in oxygen extraction or ventilation equivalent for oxygen between the groups with both arm exercises. However, the lighter exercise on the treadmill, which for the young men made a similar metabolic demand to the second arm exercise, gave significantly different values for the elderly. The older men used more energy, had a lower respiratory efficiency and higher pulse rates for the walking than the young men. The heavier treadmill exercise further increased these differences between young and old. The elderly men thus seemed to be able to do even quite hard exercise very efficiently if they were stationary, whereas the movements of walking caused a marked lowering in their efficiency. 5. The detailed results are discussed and compared with some finding of other authors. © 1956 The Physiological Society