Change in Physical Activity During a Weight Management Intervention for Breast Cancer Survivors: Association with Weight Outcomes

Objective This study examined the effects of a group phone‐based weight management intervention on change in physical activity as measured via accelerometer and self‐report in rural breast cancer survivors. The study also evaluated the role of physical activity on clinically meaningful cut points for weight loss (baseline to 6 months) and weight loss maintenance (6 to 18 months). Methods Participants were breast cancer survivors in a weight management intervention who provided valid weight and accelerometer data (N = 142). Participants were categorized into four groups based on weight loss ≥10% and weight regain ≥5% at 18 months. Results Accelerometer‐measured moderate‐to‐vigorous physical activity (MVPA) significantly increased from baseline to 6 months (+46.9 minutes). MVPA declined during maintenance but remained significantly greater than baseline. Self‐reported MVPA followed a similar pattern as accelerometer MVPA, but estimates were significantly higher. Participants in the high loss, low regain group had significantly higher MVPA at all points. Conclusions A distance‐based weight management intervention for survivors improved physical activity outcomes over 18 months. Self‐reported physical activity was substantially higher than accelerometer measured. Findings highlight the importance of device‐based measurement for characterizing the magnitude of physical activity change as well as the role of physical activity in weight management outcomes.