Human skeletal muscle remodeling in frail elderly after progressive resistance training

There is a progressive decline in muscle mass and in physical activity in elderly persons. The purpose of this study was to examine the morphological, ultrastructural, and biochemical adaptations of frail elderly skeletal muscle to progressive resistance training (PRT). Embryonic and neonatal myosin heavy chain isoform (eMHC, nMHC) and insulin like growth factor-I (IGF-I) were examined in this study to explore whether frail elderly skeletal muscle has a myogenic response to PRT.;Muscle biopsy were taken from the vastus lateralis to examine age and exercise effects. Frail elderly subjects (age = 86.2 ;A 10 week randomized controlled trial of PRT was conducted in frail elderly. The strength was improved 113 ;This study indicates that ten weeks of PRT greatly improves muscle strength without an increase in muscle fiber CSA. The ultrastructural and biochemical changes may be indicative of a process of adaptation which includes degeneration/injury and regeneration/repair of skeletal muscle in response to PRT. This process is accompanied by substantial functional improvements in muscle performance indicative of the plasticity of the neuromuscular system even in the ninth and tenth decades of life.