Sex differences in time to task failure during early pubertal development

Abstract

We compared fatigability and activation of elbow flexor muscles in children at 3 pubertal stages during a sustained submaximal contraction. In 72 healthy children (39 boys) aged 11 ± 3 years (range, 8-14 years), differences in fatigability (time to task failure) and muscle activation were compared at 3 Tanner stages (T1-T3). Time to task failure and muscle activation were similar between boys and girls at prepubertal Tanner stage 1. Time to task failure was briefer for girls than boys at Tanner stages 2 and 3 and was predicted by the coactivation indices and percent body fat in girls. Muscle torque was the only predictor for the time to task failure in boys. Differences in fatigability and muscle coactivation were evident during the initial pubertal stages (T2 and T3), but not before the onset of puberty (T1).