Abstract Body (Do not enter title and authors here): Background: The LITE randomized clinical trial evaluated the effect of high-intensity vs low-intensity walking exercise on walking ability for peripheral artery disease (PAD). In post-hoc analyses, this study evaluated whether people with PAD who walked more exercise minutes per week had greater six-minute walk (6MW) improvement, compared to those who walked fewer exercise minutes per week. Within each quartile of exercise minutes, change in 6MW was compared between high and low-intensity exercise groups.
Methods: People with PAD were randomized to walking exercise that induced ischemic leg symptoms (high-intensity), walking exercise at a comfortable pace without ischemic leg symptoms (low-intensity), or a control group that did not exercise for 12 months. Participants randomized to exercise were asked to walk 5 days/week up to 50 minutes/day. High-intensity exercise was defined and objectively measured using an ActiGraph. Participants wore an ActiGraph during exercise to measure exercise minutes/week. The primary outcome was 12-month change in 6MW.
Results: Of 305 PAD participants randomized (47% women, 59% Black), 208 were assigned to exercise and had data available for analyses. The high-intensity exercise group walked fewer exercise minutes/week than the low-intensity exercise group (51.95 vs 136.82, P< 0.0001). In each exercise group, greater exercise minutes/week at target intensity were associated with greater 6MW improvement (Table). Within each quartile of exercise minutes/week, high-intensity exercise improved 6MW significantly more than low-intensity (Table).
Conclusion: In the LITE randomized trial, among people randomized to high-intensity and low-intensity exercise, respectively, more minutes of exercise per week were associated with greater 6MW improvement. However, within each quartile of exercise minutes/week, high-intensity exercise improved 6MW significantly more than low-intensity exercise.