respect
biological age
sexual
maturation
METHODS: Physical fitness was measured in a sample of Spanish adolescents (N. = 2859; 1357 males, 1502 females) from the AVENA study, by means of the following tests: sit and reach, handgrip, standing broad jump, bent arm hang, 4 x 10 m shuttle run, and 20 m shuttle run. Percentage body fat, fat free mass and leisure-time physical activity were used as confounders. Adolescents were classified according to chronological age and biological age (measured by Tanner stages). All the analyses were adjusted for the above- mentioned confounders.