Consequences of sport training during puberty

Growth at puberty depends on one's genetic potential, nutritional status an d a series of hormones. Energy expenditure may modify the effects of these three factors on the linear growth rate and the relative proportions of fat -free and fat mass. Participation in sports where weight control is not req uired does not seem to affect pubertal timing or alter linear growth rate. The growth and maturation of athletes in weight control sports have the add itional burden of energy output greater than intake; however, in only a min ority the energy deficit is great enough to slow growth and maturation. Stu dies focusing on male wrestlers and female gymnasts are reviewed. In the wr estlers the hormonal picture is consistent with mild-to-moderate GH resista nce and perhaps mild maturational delay, especially in the lower weight cla sses. The deficits in lean body mass and fat mass "catch-up" quickly follow ing the end of training and competitive season. The situation with the gymn asts is somewhat different, the goal being to develop muscular strength wit hin a shorter and lighter physique. Marked under-nutrition can keep these a dolescents pre-pubertal for many years of training and competition. Whether subsequent growth is disproportionate or not remains indeterminate, but th e marked delay in the onset of estrogen action can permanently cause the sk eleton to be under-mineralized. In conclusion, most athletes continue to tr ack along the centiles of their genetic potential. To define the mechanisms of growth and maturational delay one must longitudinally study children in weight-control sports. (C) 2001, Editrice Kurtis.