体幹重量負荷歩行と傾斜歩行の酸素摂取量,心拍数ならびにダブルプロダクトに及ぼす影響

Abstract

Variations in the oxygen uptake, heart rate, and double product (=systolic blood pressure X heart rate) of 8 young adult males were investigated in a series of treadmill-walking tests. The speed of the treadmill was set at 4 km/hr, with gradients varied at 0%, 3%, 6%, and 9%. Subjects first walked the treadmill unburdened, then while bearing backpack loads of 10% and 20% of their body weight. Oxygen uptake, heart rate, and the double product were all found to increase as the load weight rose. However, the rate of increase resulting from added backpack weight with the treadmill gradient remaining at 0% was less than that resulting from raising the treadmill gradient with the subject unburdened. The ratio between the increase in heart rate and the rise in oxygen uptake was also lower in the former case than in the latter. Treadmill gradient was thus found to have a greater influence than load weight on oxygen uptake in healthy subjects. Clinically, this finding suggests that when using a fixed-speed treadmill for therapeutic exercise. gradient variation should be implemented first, followed by gradient variation in conjunction with the increase of backpack load weight.