Clark, B. C., Manimi, T. M., The, D. J., Doldo, N. A., & Ploutz-Snyder, L. L. (2003). Role of contraction type and activation strategies in fatigability differences between males and females. Medicine and Science in Sports and Exercise, 35(5), Supplement abstract 809.

This study evaluated 1) gender differences in back extensor fatigability during isometric and isotonic muscular contractions, 2) the relationship between absolute load and endurance time, and 3) gender differences in neuromuscular activation and fatigue patterns of the lumbar and hip extensors during fatiguing isometric trunk extension. Ss (M = 10; F = 10) performed isometric and isotonic trunk extensions to failure. The load was 50% of maximal voluntary contraction.

Females exhibited a longer endurance time than males during the isometric task but there was no difference in the isotonic exercise. Absolute load was significantly but weakly related (r = .34) to isometric endurance time in the total sample but not when the genders were analyzed separately. There were no gender differences in EMG muscle activation patterns. There were gender differences in median frequency shifts with females demonstrating similar fatigue in the biceps femoris and lumbar extensors, while males exhibited more pronounced fatigue in the lumbar musculature than the biceps femoris. Lumbar extension was more associated with endurance in males than in females.

Implication. It is inappropriate and too simple to state that females endure fatigue better than males. Gender differences in muscle endurance are dependent upon contraction type, absolute load, and frequency shifts in the EMG signal. Gender superiority, when it is evidenced, is determined by these and assumedly other factors.

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