CARDIOVASCULAR, NEUROMUSCULAR, AND METABOLIC ALTERATIONS WITH AGE LEADING TO FRAILTY

As members of our society live longer, a greater percentage of the pop ulation will he older. These demographic changes will stress our socia l and medical delivery system, unless interventions can alter the cour se leading to frailty. Maximal aerobic power decreases with age, due t o a decrease in cardiac output, and is exacerbated by cardiovascular d isease. Asymptomatic aging does not reduce cardiovascular function to an extent that would lead to loss of function. Metabolism, endurance, and contraction velocity and muscle strength remain relatively high un til 40, 50, and 60 years of age, respectively. After age 60, there are dramatic decreases (approximately 10% per year) which lead to loss of function and independence. The loss of muscle function leads to an in crease in the likelihood of falls (approximately 4-fold). Exercise pro grams utilizing ''aerobic'' exercise activities do not lead to an incr ease in muscle function, whereas programs designed specifically for mu scle can increase function and, presumably, reduce the risk of falls a nd injuries.