Deschenes, M. R., McCoy, R. W., & Holdren, A. N. (2007). Gender influences neuromuscular adaptations to muscle unloading. ACSM Annual Meeting New Orleans, Presentation Number, 2363.

This study examined whether young men and women demonstrate different neuromuscular adaptations to muscle unloading. Neuromuscular function of the right knee extensors in untrained young men (N = 10), and untrained young women (N = 10) was quantified before and after one week of muscle unloading. Peak torque was assessed during a maximal effort isometric contraction with the knee set at a 95° angle, and during a set of five maximal effort isokinetic contractions performed at 1.05 rads/s. Electromyography recordings were collected during the one second isometric contraction.

Although both genders experienced significant declines in peak isometric torque as a result of unloading, the relative difference from pre- to post-unloading measures was significantly greater among women than men (~28% vs. ~15%). This was accompanied by a significantly greater unloading-induced decrement in electromyography activity of the contracting thigh muscles in women compared to men.

Implication. Untrained women lose muscle strength significantly faster than untrained men. The strength loss is likely to due to disturbances in the neural function associated with the strength activities. Whether similar differences exist among trained athletes of both genders remains to be evaluated.

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