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

Abstract

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 (VO(2) max); 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 VO(2) max.

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.

Figure 1

Older men with high compared to low habitual physical activity demonstrate better performance in measures of physical function and mobility but not strength or power. Accelerometers were used to determine the average daily physical activity counts in 82 older men and the median average daily physical activity counts was calculated for the sample. Older men who had average daily physical activity counts below the median value for the sample were assigned to the low activity group and older men above the median value were assigned to the high activity group. Evaluation of lower extremity mobility and function using the SPPB demonstrated significant differences between men with low compared to high physical activity levels (A). Likewise, measures of gait speed over a 50 meter distance (B) and the time to climb a standard flight of stairs (C) revealed significant differences between group means. Examination of upper extremity function using a lift and lower measure demonstrated that individuals with relatively high compared to low physical activity levels could complete significantly more shelves (D). Determination of maximum voluntary strength by the 1RM measure (E) and peak muscle power (F) for the leg press demonstrated a modest but insignificant difference (p = 0.076) and no difference (p = 0.359) between men with low compared to high levels of habitual physical activity, respectively. Upper extremity strength and power quantified by measuring the chest press 1RM (G) and peak power (H) were also not different between groups (p = 0.710 and 0.945, respectively). * p < 0.05 and *** p < 0.001.