Impact of Exercise Intensity on Cardiac Health in Young Adult Survivors of Childhood Cancer: The PULSE Trial

Inclusion Criteria: * Current age at study initiation 18-39 years. * Cancer diagnosis at age ≤ 18 years. * Previous exposure to any dose of anthracyclines. * Are ≥2 years post-treatment and in remission without relapse after cancer directed therapy. * Eastern Cooperative Oncology Group Performance Status = 0 * Oncology survivorship provider clearance to participate in exercise * No self-reported comorbidities or contraindications that prohibit the undertaking of high intensity exercise (e.g., severe valvular heart disease) * Sedentary (i.e., currently participates in ≤ 60 minutes of structured high or moderate intensity exercise/week) determined by self-report during screening using the Godin Leisure Time Exercise Questionnaire * Speak English * Willing to travel to Dana-Farber Cancer Institute for necessary data collection Exclusion Criteria: * Unstable comorbidities that prevent participation in moderate-to-vigorous intensity exercise. * Patients who are pregnant. * Participate in more than 60 minutes of structured moderate-to-vigorous exercise per week over the last month. * Patients receiving treatment for other active malignancies (except basal cell carcinoma). * Subjects who in the opinion of the investigators, may not be able to comply with the safety monitoring requirements of the study. * Unable to travel to DFCI Longwood campus for necessary data collection.