Functional and Metabolic Consequences of Sarcopenia

Abstract

The capacity of older men and women to adapt to regularly performed exercise has been demonstrated by many laboratories. Aerobic exercise results in improvements in functional capacity and reduced risk of developing type II diabetes in the elderly. High intensity resistance training (above 60% of the 1 repetition maximum) causes large increases in strength in the elderly, and resistance training significant increases muscle size. Resistance training also significantly increases energy requirements and insulin action of the elderly. We recently demonstrated that resistance training has a positive effect on multiple risk factors for osteoporotic fractures in previously sedentary post-menopausal women. Because the sedentary lifestyle of individuals in a long-term care facility may exacerbate losses of muscle function, we applied this same training program to frail, institutionalized elderly men and women. In a population of 100 nursing home residents, a randomly assigned high intensity strength training program resulted in significant gains in strength and functional status. In addition, spontaneous activity, measured by activity monitors, increased significantly in those participating in the exercise program; there was no change in the sedentary control group. Before the strength training intervention, the relationship of whole-body potassium and leg strength was relatively weak (r2 = 0.29, P < 0.001), indicating that in very old persons muscle mass is an important but not the only determiner of functional status. Thus exercise may minimize or reverse the syndrome of physical frailty prevalent among very old individuals. Because of their low functional status and high incidence of chronic disease, there is no segment of the population that can benefit more from exercise training than the elderly.