Nemoto I, Kanehisa H, Miyashita M
Human Performance Laboratory, Toho University School of Medicine, Tokyo, Japan.
J Sports Med Phys Fitness. 1990 Mar;30(1):83-8.
To elucidate the effect of sports training on age-related changes of body composition and isokinetic peak torque (IPT) in knee extensors, junior speed skaters were tested in comparison with relatively sedentary age-matched controls. Subjects consisted of 132 male and 71 female junior speed skaters (SSs; aged 10-18 years). Two-hundred and thirty-six males and 265 females between the ages of 10 to 18 in the same geographic area were also tested as controls (Cs). Lean Body Mass (LBM) and relative body fat (%) were estimated from skinfolds, using the equations for preadolescent boys and girls. An isokinetic dynamometer (Cybex II) was used to measure IPT (Nm) produced at angular velocities corresponding to 0, 30, 180, 300 deg.sec-1 during maximal knee extensions. SSs were heavier in body weight and LBM from age 13 for males and from age 16 for females than the Cs, and there were significant differences in LBM between SSs and Cs after age 16 regardless of sex. The female Cs showed a gradual increase in relative body fat (%) after age 14, however, such a trend was absent in female SSs. IPT increased in any angular velocity with age from 10-18 years in the male Cs, and from 10-15 years in the female Cs. On the other hand, male SSs tended to be stronger after age 13 and female SSs stronger after age 16. Significant differences between the two groups were obtained only at lower angular velocities from 16 years of age in both sexes.(ABSTRACT TRUNCATED AT 250 WORDS)
为了阐明体育训练对身体成分与膝关节伸肌等速峰值扭矩（IPT）的年龄相关变化的影响，对青少年速滑运动员进行了测试，并与年龄匹配的相对久坐不动的对照组进行比较。受试者包括132名男性和71名女性青少年速滑运动员（SS组；年龄10 - 18岁）。在同一地理区域内，还测试了236名年龄在10至18岁之间的男性和265名女性作为对照组（C组）。使用针对青春期前男孩和女孩的公式，通过皮褶厚度估算瘦体重（LBM）和相对体脂率（%）。使用等速测力计（Cybex II）测量在最大膝关节伸展过程中，对应于0、30、180、300度·秒⁻¹角速度时产生的IPT（牛顿米）。男性从13岁起、女性从16岁起，SS组的体重和LBM均高于C组，且16岁后无论性别，SS组和C组的LBM均存在显著差异。女性C组在14岁后相对体脂率（%）逐渐增加，而女性SS组则没有这种趋势。男性C组在10 - 18岁、女性C组在10 - 15岁时，IPT随年龄在任何角速度下均增加。另一方面，男性SS组在13岁后往往更强壮，女性SS组在16岁后更强壮。两组之间仅在16岁时较低角速度下存在显著差异。（摘要截断于250字）
