Submitted to: Journal of the American Geriatrics Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/1/2010
Publication Date: 9/1/2010
Citation: Morie, M., Reid, K., Miciek, R., Lajevardi, N., Choong, K., Krasnoff, J.B., Storer, T.W., Fielding, R., Bhasin, S., Lebrasseur, N.K. 2010. Habitual physical activity levels are associated with performance in measures of physical function and mobility in older men. Journal of the American Geriatrics Society. 59(9):1727-1733. Interpretive Summary: As we age, it becomes increasingly difficult to perform activities such as walking, climbing stairs and lifting objects. Being limited in the ability to perform such activities increases the risk for falls, disability, hospitalization, and even death. Thus, there is merit in identifying ways to decrease or reverse age-related limitations in physical performance. In this study we wanted to determine whether an older person’s normal physical activity level as measured by a technology called accelerometry (similar to a pedometer but measures activities other than walking) predicts their performance in various measures of balance, walking, stair climbing, lifting, cardiorespiratory fitness and muscle strength. Eighty-two community-dwelling men 65 years of age or older who reported difficulty walking a ¼ mile or climbing a flight of stairs participated. We observed that older men with higher compared to lower physical activity levels demonstrated a significantly better score on a measure of balance, walking speed and the ability to rise out of a chair. In addition, older men with higher activity levels exhibited a significantly faster walking speed and climbed a standard flight of stairs faster than less active peers. More active men also completed more shelves in a lift and lower task. Measures of upper body and lower extremity muscle strength were not different between the low and high activity groups. Additional analyses showed that physical activity is a significant predictor of the older subjects’ performance in the measures of physical function and mobility, muscle strength and cardiorespiratory fitness. In summary, older men with higher physical activity levels demonstrate significantly better physical function and mobility than less active peers. Future work is needed to determine whether increasing physical activity levels in older individuals can improve or preserve physical performance.
Technical Abstract: Objectives: To determine whether objectively measured physical activity levels are associated with measures of physical function and mobility in older men. Design: Cross-sectional. Setting: Academic research center. Participants: Eighty-two community-dwelling men >/= 65 years of age with self-reported mobility limitations. Measurements: Physical activity by triaxial accelerometers; physical function and mobility by the Short Physical Performance Battery (SPPB), gait speed, stair climb time, and a lift and lower task; aerobic capacity by maximum oxygen consumption (VO2max); and leg press and chest press maximal strength and peak power. Results: Older men with higher compared to lower physical activity levels demonstrated a > 1.4 point higher mean SPPB score and a 0.35 m/s faster walking speed. They also climbed a standard flight of stairs 1.85 sec faster and completed 60% more shelves in a lift and lower task (all p < 0.01). Upper body and lower extremity muscle strength and power measures, however, were not significantly different between the low and high activity groups. Correlation analyses and multiple linear regression models showed that physical activity is positively associated with all physical function and mobility measures, leg press strength, and VO2max. Conclusion: Older men with higher physical activity levels demonstrate significantly better physical function and mobility than less active peers. Moreover, in older men physical activity levels are predictive of performance in measures of physical function and mobility. Future work is needed to determine whether modifications in physical activity levels can improve or preserve physical performance in later-life.