BACKGROUND This investigation aimed to: 1) confirm whether women were more vulnerable to the negative neuromuscular adaptations elicited by muscle unloading and if so, 2) determine which physiological mechanism(s) explain those gender-related differences. METHODS Healthy young men (20.7 ± 0.3 yrs) and women (20.3 ± 0.3 yrs) - (N=12/group) -participated by completing neuromuscular functional tests before and after 7 d of unloading. RESULTS During isokinetic testing of peak torque, work performed, and power, women displayed significantly (P ≤ 0.05) greater declines in performance than men at 1.05 and 2.09, but not 0.53 rads/s. During maximal isometric contractions, women experienced greater strength decrements. Similar gender-specific adaptations to unloading were found in EMG activity, but not muscle mass, neuromuscular transmission, or force relative to EMG. CONCLUSIONS Women are more susceptible to the adaptations of muscle unloading, and disturbances in neural drive from the central nervous system are probably responsible.

Chronic resistance training was found to be ineffective in neutralizing the deleterious effects of unloading on neuromuscular function. It appears that positive adaptations associated with long-term resistance training provide no prophylactic effect when neuromuscular systems are subjected to unloading.