Preteens and weight training. (Pediatric News, September 1993)

An often-asked question posed by parents to their pediatricians concerns the use of weights by preteens to increase their strength and bulk. The questions that are usually asked are first whether weight-lifting in children before they've reached puberty is actually helpful and secondly, can this activity be harmful? Some answers to these questions were given by speakers at a meeting of the American Medical Society for Sports Medicine.

Over the years, the impression among physicians has been that a certain adequate amount of circulating androgens (male hormones) are necessary before strength can be gained through weight training. This level of androgens occurs at the time of puberty and so it has been thought that training before puberty is nonproductive.

However, several studies have shown that this is not the case and that prepubertal weight training is beneficial. These investigations have shown weight training to contribute to "increased strength, reduced skin-fold thickness, greater arm girth, improved motor performance, and increased flexibility." Other investigators have shown that "preadolescents respond to a strength-training program with an increase in muscle mass roughly 50% of that seen in adults who undergo strength training." Besides the improvement in strength, it has also been shown that there are significant improvements in self-concept and peer ...