Rates of Recovery From Strenuous Exercise in Physically Active Older Adults

There is a well-conceived notion that the recovery from strenuous exercise gets slower as individuals get older in age. Studies using animal models have demonstrated that stretching of electrically-activated skeletal muscle to mimic eccentric muscle contractions results in a greater decline and slower recovery in muscular force in old mice than in young mice. Similarly, in human studies using sedentary adults, age has been associated with a slower rate of recovery from a series of eccentric contractions. However, the process of aging is often confounded by coexisting diseases and gradual sedentary lifestyles that progress with advancing aging. Could older adults who are apparently healthy and habitually exercising demonstrate slower rates of recovery from strenuous exercise? In a small-scale study, recreationally-active middle-aged adults did not display a slower recovery from unaccustomed eccentric exercise than young adults. Masters athletes are an effective experimental model to address this question as extrinsic factors (e.g., deconditioning, chronic degenerative diseases) that often confound the intrinsic aging process can be minimized in this population. As no study has been conducted in Masters athletes, it is unknown if Masters athletes would experience slower rates of recovery similar to their sedentary peers. With this information as background, the general aim of the proposed study is to determine if older adults who are healthy and physically active demonstrate slower rates of recovery from unaccustomed strenuous exercise of downhill running than younger peers. In an attempt to properly determine the influence of aging and regular physical activity, 4 groups of apparently healthy adults, including young sedentary, young trained, older sedentary, and older trained adults, will be studied. A total of 60 apparently healthy men and women will serve as subjects. Half will be young \[18-40-year-old (n=30)\] and the other half older \[50-80-year-old (n=30)\]. After the screening and familiarization, investigators will ask participants to visit the laboratory four times (four consecutive days) to perform downhill running and to test physiological measurements (muscular strength, pain scale, range of motion, arterial stiffness and blood pressure and blood creatinine and myoglobin concentrations).