Ramos E, Frontera W R, Llopart A, Feliciano D
Center for Sports Health and Exercise Science, Department of Physical Medicine, Rehabilitation and Sports Medicine, University of Puerto Rico School of Medicine, San Juan, USA.
Int J Sports Med. 1998 Nov;19(8):526-31. doi: 10.1055/s-2007-971955.
The purpose of the present investigation was to study muscle strength in adolescents and its relationship to serum levels of testosterone and growth hormone in both genders. Thirty active adolescents (15 boys; age range 11 -12 y/o) participated in the first study. Isokinetic muscle strength of the dominant knee extensors (KE) was determined at 0, 12, 20, 30, 120, 180 and 240 deg/sec using a Cybex 340 dynamometer. The assessment of pubertal status was accomplished using the criteria of Tanner. Serum levels of total testosterone (T) and growth hormone (GH) were determined using radioimmunoassay techniques. Boys had higher (p< 0.001) T levels but no differences in muscle strength were detected between genders. Fifty-seven additional subjects representing three age groups (11-12 y/o, n=18; 13-14, n=21; 17-18, n=18) participated in the second study. A significant increase in peak torque (absolute and corrected for body weight) with age was observed in both genders. There were no significant gender differences in strength for the two youngest age groups, but boys were stronger than girls in the oldest age group (group 3). Testosterone and GH levels increased with age in boys but not in girls. Gender related differences in T were found in groups 2 and 3. A positive correlation (r=0,64 boys; r=0.46 girls) between testosterone levels and absolute muscle strength was seen in both genders. Our results suggest that increases in anabolic hormones precede muscle strength gains in adolescent males. In addition, gender related differences in muscle strength during adolescents cannot be explained solely on the basis of difference in body size or T levels.
本研究的目的是探讨青少年的肌肉力量及其与男女血清睾酮和生长激素水平的关系。30名活跃的青少年（15名男孩；年龄范围11 - 12岁）参与了第一项研究。使用Cybex 340测力计在0、12、20、30、120、180和240度/秒的速度下测定优势膝伸肌（KE）的等速肌力。采用坦纳标准完成青春期状态评估。使用放射免疫测定技术测定血清总睾酮（T）和生长激素（GH）水平。男孩的T水平较高（p<0.001），但未检测到性别之间的肌肉力量差异。另外57名代表三个年龄组（11 - 12岁，n = 18；13 - 14岁，n = 21；17 - 18岁，n = 18）的受试者参与了第二项研究。观察到男女的峰值扭矩（绝对值和经体重校正后）均随年龄显著增加。两个最年轻年龄组在力量上没有显著的性别差异，但在最年长年龄组（第3组）中男孩比女孩更强壮。男孩的睾酮和生长激素水平随年龄增加，而女孩则不然。在第2组和第3组中发现了与性别相关的睾酮差异。男女的睾酮水平与绝对肌肉力量之间均呈正相关（男孩r = 0.64；女孩r = 0.46）。我们的结果表明，合成代谢激素的增加先于青少年男性肌肉力量的增加。此外，青少年时期肌肉力量的性别相关差异不能仅基于体型或睾酮水平的差异来解释。
