Habitual physical activity levels are associated with performance in measures of physical function and mobility in older men

OBJECTIVES: To determine whether objectively measured physical activity levels are associated with physical function and mobility in older men. DESIGN: Cross-sectional. SETTING: Academic research center. PARTICIPANTS: Eighty-two community-dwelling men aged 65 and older with self-reported mobility limitations were divided into a low-activity and a high-activity group based on the median average daily physical activity counts of the whole sample. MEASUREMENTS: Physical activity according to triaxial accelerometers; physical function and mobility according to the Short Physical Performance Battery (SPPB), gait speed, stair climb time, and a lift-and-lower task; aerobic capacity according to maximum oxygen consumption (VO₂max); and leg press and chest press maximal strength and peak power. RESULTS: Older men with higher physical activity levels had a 1.4-point higher mean SPPB score and a 0.35-m/s faster walking speed than those with lower physical activity levels. They also climbed a standard flight of stairs 1.85 seconds faster and completed 60% more shelves in a lift-and-lower task (all P<.01); muscle strength and power measures 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 better physical function and mobility than their less-active peers. Moreover, physical activity levels are predictive of performance in measures of physical function and mobility in older men. Future work is needed to determine whether modifications in physical activity levels can improve or preserve physical performance in later life.