Relation of non-exercise walking activity with exercise performance in patients with peripheral artery disease: NEW activity for PAD

Introduction: Community-based structured exercise training (CB-SET) programs are beneficial for patients with peripheral artery disease (PAD). However, the impact of lower levels of walking activity accumulated separately from formal exercise is unclear. The aim of this study was to determine the relation of non-exercise walking (NEW) activity with exercise performance in PAD. Methods: This was a post hoc analysis from twenty patients with PAD enrolled in a 12 week CB-SET program using diaries and accelerometry. Formal exercise (3 sessions·week⁻¹) was detected using patient-reported diary entries that corresponded with accelerometer step data. NEW activity was characterized as steps completed over five days each week, excluding steps achieved during formal exercise sessions. The primary exercise performance outcome was peak walking time (PWT) assessed on a graded treadmill. Secondary performance outcomes included claudication onset time (COT) from the graded treadmill and peak walking distance (PWD) achieved during the six-minute walk test (6MWT). Partial Pearson correlations evaluated the relation of NEW activity (step·week⁻¹) with exercise performance outcomes using exercise session intensity (step·week⁻¹) and duration (min·week⁻¹) as covariates. Results: NEW activity demonstrated a moderate, positive correlation with change in PWT (r=0.50, p=0.04). Other exercise performance outcomes were not significantly related to NEW activity (COT: r=0.14; 6MWT PWD: r=0.27). Conclusions: A positive association was demonstrated between NEW activity and PWT following 12 weeks of CB-SET. Interventions to increase physical activity levels outside of formal exercise sessions may be beneficial for patients with PAD.