Gender comparisons in neural, morphological, and protein muscle markers of adaptation to acute resistance training

This study examined the time course of strength development, electromyography (EMG) amplitude, histochemical fiber type, fiber cross-sectional area, and single fiber MHC adaptations in men and women during 4 weeks of resistance training. Ten untrained men and ten untrained women performed a progressive leg extension protocol three times per week. In addition to the three training days per week, there was a testing day before training began and at the end of weeks 1, 2, and 4. Testing days consisted of a muscle biopsy (vastus lateralis) and measurement of EMG, isometric peak torque (PT), and one repetition maximum (1 RM). Muscle histochemical analyses were completed using NADH and ATPase (pH 4.55) stains. Single fiber myosin heavy chain (MHC) distribution was determined by SDS-PAGE. Men exhibited greater 1 RM, EMG, and isometric PT values at each time point (p < 0.05). The men and the women exhibited significant increases (26% and 38%, respectively) in 1-RM from pre to posttraining. There were no differences between genders or across time for fiber type, muscle fiber cross-sectional area, or MHC distribution. The results indicate that the muscle protein and neural adaptations to 4 weeks of resistance training are similar for men and women.