It is generally stated that japanese young persons are becoming feeble in muscle strength because of lack of exercise. The development of muscle strength is caused by the increase of muscle mass. The questions arise: Does lack of exercise in adlescence decrease muscle mass? As to V́O_2 max and PWC_<170> which are the most valid indices of physical fitness, what numerical value do they take? To investigate the above-mentioned. body composition, back strength. V́O_2 max and PWC_<170> were measured in 94 male students (mean age: 18.6). The results obtained were as follows: 1) Subjects were divided into two groups by their exercise experiences: exercise group and non-exercise group. There were no significant differences except items of aerobic capacity between two groups. 2) Exercise group was better than non-exercise group about aerobic capacity (P < 0.05). 3) The correlation between LBM and back strength in exercise group was found to be 0.447 (p < 0.01). 4) The correlation between LBM and V́O_2 max in exercise group was found to be 0.600, and in non-exercise group to be 0.470 (p < 0.01). 5) The correlation between LBM and PWC_170 in exercise group was found to be 0.603, and in non-exercise group to be 0.435 (p < 0.01). 6) Subjects were divided into three groups on percentile Fat: under 33.3% group, 33.3% - 66.6% group and over 66.6% group. Among three groups, back strength per 1 kg of body weight and back strength per 1 kg of LBM were compared. In regard to only back strength per 1 kg of dody weight, over 66.6% group was inferior (p < 0.05 ). From these results, the conclusion seems to be able to be drawn that exercise in adlescence improves muscle in quality and contributes to the developments of muscle mass and muscle strength. but in a statistic point of view it cannot be asserted that it is right, because we could recognize the significant difference only in aerobic capacity, In regard to the decrease in muscle strength, our data did not indicate that the lack of exercise caused muscle mass to decrease. But we may conclude that decrease in muscle mass in reverse proportion to increase in body fat storage weakens muscle strength.
男子学生の身体組成と筋力・有酸素能力について
kiyo36_bunka_pp233-243.pdf
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