There is a well-documented association between physical activity & risk for breast cancer development and recurrence. It is known that exercise interventions have been effective at increasing physical activity levels in breast cancer survivors. Knowing that breast cancer survivors are less active than non-cancer patients, a less active lifestyle places them at risk of obesity and poor overall health, which in turn also increases risk of cancer and cancer recurrence. Not all the reasons for the risk reduction are clear, however it is known that hormones and other inflammatory markers play a role.

This study has three goals:

1. To investigate the feasibility of a home intervention designed to reduce sedentary behavior.
2. Describe the effects of the intervention on levels of sedentary behavior, physical activity, and symptoms.
3. Assess cost of the intervention.

There is a well-documented association between physical activity and risk for breast cancer development and recurrence. Exercise training interventions have been effective at increasing physical activity levels in breast cancer survivors, however they require 1) a large degree of patient initiative to achieve positive health outcomes associated with sustained behavioral change and 2) facilities and oversight that may be prohibitive in a clinical setting. Although most activity-based research to date has focused on increasing levels of moderate to vigorous physical activity (MVPA) for breast cancer survivors, large epidemiological studies suggest that breast cancer survivors are also more sedentary when compared to non-cancer controls. A recent meta-analysis of controlled intervention trials designed to promote physical activity among sedentary cancer survivors found that none of the trials within the scope of the review succeeded in achieving 75% or better adherence to prescribed exercise guidelines, leading the authors to question whether shifting the target of intervention from MVPA to reductions in sedentary time might be a more realistic goal. Recent research suggests that interventions designed to reduce sedentary time in breast cancer survivors have the potential to yield clinically meaningful health benefits, especially for individuals at higher risk for sedentary behaviors, however the optimal method of intervention is not clear.

Aim 1: Feasibility of the intervention Assess the feasibility of an intervention designed to reduce sedentary behavior in breast cancer survivors. The behavioral intervention will involve the review of a 7-day baseline snapshot of sedentary behavior and physical activity patterns, combined with tailored activity prompts described over the following 6 weeks.

Aim 2: Effects of the intervention Aim 2a: Describe a preliminary range of effect sizes of the intervention on levels of sedentary behavior, physical activity and symptoms of cancer survivorship (e.g. cancer related fatigue).

Aim 2b: Evaluate the relationship between change in sedentary behavior and change in cancer-relevant outcomes, such as fatigue and biomarkers of cancer recurrence (e.g. IGF-1, Leptin), following the reduced sedentary time intervention.

Aim 3: Assessment of intervention components Aim 3a: Quantitatively assess overall cost of the intervention and its individual components, dose delivered and dose received by intervention participants Aim 3b: Quantitatively describe intervention participants' perspectives on the impact of the individual intervention components, including which components appeared most useful for reducing sedentary time.

Inclusion Criteria:

• Stage I-III breast cancer survivors 20-80 who have completed primary treatment (surgery, radiation and/or chemotherapy) greater than 6 months but less than 5 years ago. Patients may be on adjuvant hormonal therapy
• BMI > 25 (overweight or class I/II obese)
• Not meeting current guidelines for regular exercise as defined by less than 150 minutes a week of moderate to vigorous physical activity
• No gain or loss of >10% body weight over the prior 6 months.

Exclusion Criteria:

• Known diabetes
• Known coronary artery disease
• Pregnancy
• Any injury that would limit mobility or require use of assisted mobility devices
• Weight gain or loss of >10% body weight over the prior 6 months
• Greater than 150 minutes a week of moderate to vigorous physical activity
• Inability to provide informed consent
• Non-english speaking