Internet-Based Physical Activity Intervention for Women With a Family History of Breast Cancer

Objective: Physical inactivity is a modifiable risk factor for breast cancer. Physical activity interventions that can be delivered through the Internet have the potential to increase participant reach. The efficacy of an Internet-based physical activity intervention was tested in a sample of women at an elevated risk for breast cancer. Method: A total of 55 women with at least 1 first-degree relative with breast cancer (but no personal history of breast cancer) were randomized to a 3-month theoretically grounded Internet-based physical activity intervention or an active control arm. Minutes of moderate to vigorous physical activity, psychosocial mediators of physical activity adoption and maintenance, as well as worry and perceived risk of developing breast cancer were assessed at baseline, 3-month, and 5-month follow up. Results: Participants were on average 46.2 (SD = 11.4) years old with a body mass index of 27.3 (SD = 4.8) kg/m(2). The intervention arm significantly increased minutes of moderate to vigorous physical activity compared to the active control arm at 3 months (213 vs. 129 min/week) and 5 months (208 vs. 119 min/week; both ps < .001). Regression models indicated that participants in the intervention had significantly higher self-efficacy for physical activity at 3 months (p < .01) and borderline significantly higher self-efficacy at 5 months (p = .05). Baseline breast cancer worry and perceived risk were not associated with physical activity. Conclusion: Findings from this study suggest that an Internet-based physical activity intervention may substantially increase physical activity in women with a family history of breast cancer.