Hypertrophy and Testosterone Levels.
It is a popular belief that a large muscle mass and hypertrophy resulting from weight training programs are related to high levels of the male sex hormone testosterone. This is particularly true regarding the so-called masculinizing effect of weight training in females. Although these ideas may be popular, they are not supported by scientific fact. For example, correlations among serum testosterone, body composition, and muscular strength were all non-significant in both high school and college men and women. In another study , similar no significant correlations were found., and in addition, it was concluded that chronic androgen (testosterone) levels do not change significantly in adult men and women during the course of weight training programs. Although blood levels of testosterone are elevated following single bouts of maximal exercise, including weight training, no physiological significance of this response is apparent.
Because the preceding studies were conducted only on adults, the question may be raised as to whether there is a difference in the response of pre-and post-pubescent children to strength-training programs. In this case, blood levels of testosterone would be different in a more physiological or functional sense. From this type of study, it was found for prepubescent boys no consistent pattern of strength changes was noted following a weight-training program. On the other hand in post- pubescent boys there were significant increases in strength in all muscles tested. These results suggest that the presence of testosterone may at least be a prerequisite for promoting strength gains and that weight training programs for the purpose of increasing muscular strength in prepubescent children are not effective. Obviously, more research along these lines are required to clarify this and related issues.