Does Sex Affect the Muscle Strength and Regional Lean Tissue Mass Response to Resistance Training in Older Adults?

Abstract

This study examined if the adaptation in muscle strength and whole body and regional lean tissue mass (LM) differs in older men (M) and women (W) subsequent to a program of high-intensity resistance exercise. Ten men and six women aged 65-78 yr underwent 20 weeks of training, twice per week, for 3 sets of 8RM for 7 upper and lower body exercises. Dynamic muscle strength was determined by 1-RM and isometric knee extensor strength by dynamometry. Lean tissue mass was determined by dual energy X-ray absorptiometry. Following training, men and women exhibited significant (p<0.001) though similar increases in dynamic upper (women, 28.9±11.7%; men, 32.0±11.1%; mean±SD) and lower (W, 38.4±14.7%; M 30.3±11.7%) body strength, and isometric knee extensor strength. There was a significant time effect (p<0.001) for whole body LM (W, 0.85±0.83 kg; M, 0.70±0.70 kg), upper limb LM (W, 0.21±0.16 kg; M, 0.25±0.13 kg), lower limb LM (W, 0.38±0.42 kg; M, 0.27±0.41 kg) and trunk LM (W, 0.25±0.38 kg; M 0.18±0.34 kg), with no interaction (p=0.58-0.78). These results suggest that well-functioning older men and women show similar gains in muscle strength and whole body and regional lean tissue mass indicating comparable neuromuscular and anabolic responses accompanying resistance training.