Children and adolescents present less blood lactate concentrations ([la]) than adults under certain loads. It is suggested that these differences are related to maturational aspects. The aim of this study was to verify the influence of sexual maturation, chronological age and growth indices (body weight, height and sum of two skinfolds - subscapular and triceps) over the lactate threshold velocity, in the fixed lactate concentration of 2.5 mmol.l-1 (V2,5) and in the 20 minutes running (V20). Thirty-three boys, aged 13-15 years, who practice different sports were submitted to: 1) anthropometrical and sexual maturation evaluations through the Tanner index (sexual maturation of genitals and pubic hair); 2) progressive discontinuous test (3 x 800m in running track) to determine V2,5; and 3) 20 minutes running test to determine the V20 and final blood [la]. There were no associations between V2,5 and sexual maturation, neither chronological age nor growth index. As the only association verified was between V20 and height (r = 0,41; p < 0,05), the authors conclude that during adolescence other performance, physiological and/or biomechanical variables may play a greater role in lactate threshold and in the 20 minutes running than the growth variables.
Sexual maturation; Lactate threshold; Running; Adolescents
