Gender Differences in the Fatigability of Human Skeletal Muscle. John G. Semmler, Devin V. Kutzscher, and Roger M. Enoka. Department of Kinesiology and Applied Physiology, University of Colorado at Boulder, Boulder, Colorado.
APStracts 6:0476N, 1999.
After participating in a 4-week intervention that reduced normal usage of the elbow flexor muscles, all six women, but only one of six men, experienced a marked increase in the endurance time during a low-force fatiguing contraction. The increase in endurance time was associated with an altered pattern of muscle activation that did not involve the commonly observed progressive increase in muscle activity. Rather, the muscle activity comprised intermittent motor unit activity. In those individuals who exhibited this behavior, the novel pattern of muscle activity was only present immediately after the 4 weeks of limb immobilization and not prior to the intervention or after 4 weeks of recovery. These findings suggest possible differences between women and men in the adaptations of the neuromuscular system.
Received 19 July 1999; accepted in final form 13 September 1999.
APS Manuscript Number J599-9.
Article publication pending Journal of Neurophysiology.
ISSN 1080-4757 Copyright 1999 The American Physiological Society.
Published in APStracts on 21 December 1999