This study was done to determine the extent to which body composition accounts for differences in anaerobic characteristics between 12-year-old girls and boys. Peak leg power (PP), mean leg power (MP), percent body fat, fat free mass (FFM), and lean thigh volume (LTV) were determined by various tests. Pubertal stages and salivary testosterone concentration (in boys) were used to assess sexual maturation. Laboratory anaerobic indices were compared with performances in two running tests. Blood samples were taken for lactate determination. Absolute PP and MP outputs were similar in both sexes and were better correlated with LTV in girls, whereas in boys both PP and MP were highly correlated with FFM. Although nonsignificant gender difference in lean tissue was observed, PP and MP when corrected for LTV were significantly greater in boys than in girls. Factors other than the amount of lean muscle mass should be considered in explaining the gender differences in PP and MP in early pubertal children.
E. Van Praagh and G. Falgairette are with the Laboratoire de Physiologie du Sport, U.F.R. Staps, Universitè B. Pascal, B.P. 104, 63172-Aubière, Cedex, France. N. Fellmann, M. Bedu, and J. Coudert are with the Laboratoire de Physiologie, Faculté de Médecine, Université de Clermont I, B.P. 38, 63001-Clermont-Fd, France.