Impact of High Intensity Aerobic Exercise on Aging-Related Motor Function Changes

Purpose: Impairments in motor function are predictive of adverse health outcomes including increased mortality and disability. This study investigated the longitudinal impact of high intensity aerobic exercise on motor function impairment associated with aging. Effects on baseline heart function were also evaluated. Methods: Subjects completed motor function testing including a grip strength test using the Hydraulic Hand Dynamometer, the 6-minute walk test (6MWT), responses to unexpected balance perturbations delivered by surface translation in anterior posterior direction, and self-selected gait speed. These motor function tests were administered at baseline, 1-2 months post-baseline, and 3-4 months post-baseline at the end of exercise training. Subjects were randomly assigned to an exercise or non-exercise group. The exercise group completed 36, 1-hour exercise sessions, 3 times a week over 3-4 months. Exercise was standardized for each subject and consisted of a 10-minute warm-up (range of motion exercise, walking, stretching), followed by a fast pace walk/jog on a treadmill for 40 minutes, and concluded with a 10-minute cooldown. A high intensity exercise at 80% max heart rate was aimed for as long as possible in each session. Exercise intensity was progressively increased over the weeks of training. Heart rate, blood pressure and oxygen levels were monitored throughout the exercise sessions. Data was analyzed and compared between the groups of subjects with repeated measures ANOVA Results: Preliminary results from the exercise subject, show improvement in motor function, increased self-selected gait speed and endurance (6MWT) at the mid-point and at the end of exercise regime. There were no effects on grip strength or balance control measures. Compared to baseline values, after exercise training, average resting heart rate and blood pressure measurement decreased significantly from 88 bpm, 138/89 to 75 bpm, 124/80 respectively. Conclusion: A program of sustained, high intensity aerobic exercise, at the upper limits of currently prescribed maximum heart rate is feasible in middle age and older individuals without adverse effects. Improvements in gait speed, endurance and heart function are promising.