Post-Menopausal Effects of Resistance Training on Muscle Damage and Mitochondria

The purpose of this study was to measure the effects of a 12 month, progressive resistance training intervention on muscle morphology and strength gains in postmenopausal women. Skeletal muscle biopsies were obtained from the vastus lateralis of five (N=5) independent community dwelling women, (mean age: 75.6 ± 4.28 yrs; mean height: 163 ± 5.34 cm; mean weight: 72 ± 17.5 kg) before, six months and 12 months after progressive resistance training. Muscle strength (1-RM) was measured at the same time points. After six months of training morphological analysis revealed evidence of increased proteolysis and tissue repair, and rudimentary fiber development. The percent of Z bands with mild Z band disruption increased from 43.9% at baseline to 66.7% after six months of training (p < 0.01). Mitochondrial volume also increased (% of mitochondria = 0.86% at baseline, 1.19% at six months and 1.04% at 12 months, p