Muscular Fatigue Curves of Boys and Girls

Abstract

Exponential fatigue curves for dynamic work of the forearm muscles were obtained from 200 boys arid girls ranging from 8 through 17 years of age. The fatigue parameters analyzed in relation to initial strength were fatigable strength, steady-state equilibrium strength, and relative rate of strength loss per contraction. Older children were stronger and exhibited greater fatigue. When their strength loss and steady-state levels were considered in relation to their initial strength-capacity, there were no age differences in fatigability, and sex differences were either absent or very small. At age eight, boys and girls had equal rates of strength loss per muscle contraction. Older boys, since they exerted more strength initially, tended to reach the fatigue level more rapidly than younger children. Older girls reached their fatigue level more slowly.