To compare associations of physical activity during daily life with treadmill walking performance and corridor-based functional performance measures in persons with lower extremity peripheral arterial disease (PAD).
156 men and women with PAD who completed baseline measurements and were randomized into the Study to Improve Leg Circulation (SILC) exercise clinical trial.
Main Outcome Measures
Participants completed a Gardner-Skinner treadmill protocol. Corridor-based functional performance measures were the six-minute walk, walking velocity over four meters at usual and fastest pace, and the Short Physical Performance Battery (SPPB) (0–12 scale, 12 = best). Physical activity during daily life was measured continuously over seven days with a Caltrac accelerometer.
Adjusting for age, sex, and race, higher levels of physical activity during daily life were associated with greater distance achieved in the six-minute walk (p trend =0.001), faster fast-paced four-meter walking velocity (p trend <0.001), faster usual-paced four-meter walking speed (p trend= 0.027) and a higher SPPB (p trend = 0.005). The association of physical activity level with maximum treadmill walking distance did not reach statistical significance (p trend =0.083). There were no associations of physical activity with treadmill distance to onset of leg symptoms (p trend =0.795).
Functional performance measures are more strongly associated with physical activity levels during daily life than treadmill walking measures.