RELATIVE MUSCLE LOADING AND ENDURANCE,

The endurance function for a broad range of relative loads, and the endurance functions of two groups males and females differing greatly in strength were studied. Despite the fact that the mean actual load sustained by males was almost twice that for the females, no difference in endurance was obtained between the two groups at the same relative percentage-of-maximum loads. As the relative load was increased from 25 to 100 of maximum strength the endurance of a static manual pull decreased at a diminishing rate from 252 sec to 2 sec. The obtained subject differences in endurance were unrelated to differences in strength, or to the absolute magnitude of the maintained load. This provided further evidence for the contention that endurance is a function of the relative load, not the actual response force. As expected, strength was found to be significantly correlated with stature, weight, and the length and girth of the upper and lower portions of the arm. The correlations between the endurance scores and the previously mentioned measurements yielded a picture of complete non-significance. Thus, there was no evidence of a relationship between body size and endurance when differences in strength were removed through use of the relative loading procedure. Author