ESTIMATION ON ENERGY METABOLISM DURING THE STEPPING EXERCISE / 体力科学

ABSTRACT

This study was undertaken to examine the mechanical efficiency of stepping exercise on the relations with physical characteristics such as body height, lower limb length, leg length and body weight, and the efficiency was used to estimate the energy metabolism during the stepping exercise. Thirty healthy male students, whose heights ranged from 157.6 cm to 189.0 cm, performed the stepping exercise using a platform from 10 cm to 50 cm. The stepping rate of vertical lifts per minute was fixed to 25 ascents/min., and the height of the platform was increased progressively by 10 cm on every 3 minutes. Oxygen intake during the stepping exercise was measured for the last 1 minute on every stage. Gross, net, work, and delta efficiencies were compited. The results were summarized as follows<BR>1. It was suggested that there was slightly exponential relationship between energy metabolism and work rate, which was ascribed to the decrease of work and delta efficiencies with increments in work of the stepping exercise.<BR>2. The correlation coefficients between the net efficiency and each physical characteristic were not signifficant for all heights of the platform. This result suggests that the physical characteristics have little or no effect on the mechanical efficiency of the stepping exercise.<BR>3. The mean value and the standard deviation of the net efficiency for heights of the platform above 30 cm were 14.3 and respectively. By using this mean value, energy metabolism during the stepping exercise can be calculated from the equation Y=0.0163×weight (kg) ×stepping rate (ascents/min.) ×height of the platform (m) +resting energy metabolism (kcal/min.) . The standard error of estimation was ±0.52 kcal. This value was lesser than that calculated from the regression equation between heart rate and oxygen intake during the stepping exercise.