Exercise in Metastatic Breast Cancer: EMBody

This is a randomized, two arm, single-center study designed to compare the effect of exercise versus usual care control on the clinical parameter of cardiorespiratory fitness, in patients with metastatic breast cancer with indolent disease biology over a 16-week period. This study will be enrolling up to 100 participants. Participants will be randomized 1:1 in blocks of 4 to the exercise intervention or usual care, stratified by frailty yes/no defined by baseline SPPB score ≤ 8 or \> 8. Primary Objective To compare the effect of a 16-week multimodality, virtually delivered exercise intervention on cardiorespiratory fitness measured by a modified Bruce ramp protocol treadmill test to usual care, in patients with indolent metastatic breast cancer. Secondary Objectives 1. To compare the effect of exercise versus usual care on objective physical function measured by the short physical performance battery (SBBP) 2. To compare the effect of exercise versus usual care on subjective physical functioning measured by PROMIS-29 questionnaire 3. To compare the effect of exercise versus usual care on body composition, measured by visceral adiposity, lean muscle mass, and muscle density on CT scans obtained as standard of care using SliceOmatic software 4. To compare the effect of exercise versus usual care on objective physical activity measured by accelerometer wear 5. To compare the effect of exercise versus usual care on patient reported outcomes, including fatigue (BFI) and health related quality of life (PROMIS-29) 6. To determine the fidelity of the exercise intervention, measured by changes in measures of constructs of habit and intention administered by questionnaire 7. To describe patient uptake and adherence with the intervention, measured by proportion of approached patients who consent to the study, and proportion of assigned training sessions attended by patients randomized to the exercise arm.