The goal of this clinical trial is to explore the impact that an at-home cardio-oncology rehabilitation (CORE) may have on short-term cardiovascular fitness and psychosocial wellness in pediatric cancer survivors. The main question it aims to answer are * To evaluate the efficacy of an at-home CORE model on short-term cardiovascular fitness and psychosocial wellbeing in adolescent cancer survivors. * To evaluate the exercise adherence rate among adolescents at risk for heart failure and assess barriers to compliance. * To explore which specific CORE resources are of most value to patients in creating sustainable healthy lifestyle modifications. * Hypothesis: Pediatric cancer survivors who implement exercise and dietary recommendations will demonstrate improvement in cardiovascular fitness and general wellness. A multidisciplinary team approach can facilitate adherence to a moderately rigorous exercise prescription, and thus enhance the health benefits of a CORE program at CHLA. Participants will undergo cardiovascular studies and a quality-of-life survey prior to exercise intervention, and at the end of the 6-month study period.