Researching the Effect of Exercise on Cancer

Inclusion Criteria: * Postsurgical diagnosis of patients with primary solid tumors at high-risk of relapse as defined by one of the following: ° High-risk primary solid tumor (e.g., colorectal, ovarian, non-small cell lung cancer) (colorectal cancer only for Phase 1a) * Stage 3 or * ctDNA positive ° High-risk breast cancer * Residual invasive disease in the breast or the lymph nodes following completion of neoadjuvant chemotherapy (NACT), * Estrogen receptor (ER), and/or progesterone receptor (PR) positive and HER2 negative, * CPS-EG score ≥ 3, * CPS-EG score ≥2 w ith ypN+, or * Recurrence score ≥ 25 * No evidence of disease * Age ≥ 18 * Interval of ≥ 1 month but ≤ 2 years following completion of all definitive adjuvant therapy * Non-exercising (i.e., \< 30 minutes of moderate and \< 20 mins of vigorous exercise/wk), as assessed by remote activity and heart rate tracking for a 7-day period prior to study entry) ° If ≥ 30 minutes but less than 45 minutes of moderate exercise/week, or if ≥ 20 minutes but less than 30 minutes of vigorous exercise/week, patients may be eligible, at the discretion of the PI. * Cleared for exercise participation as per screening clearance via PAR-Q+ * Willingness to comply with all study-related procedures Exclusion Criteria: * Enrollment onto any other interventional investigational study except interventions determined by the PI not to confound study outcomes * Any other current diagnosis of invasive cancer of any kind * Distant metastatic malignancy of any kind * Any other condition or intercurrent illness that, in the opinion of the investigator, makes the subject a poor candidate for study participation