 This project builds upon very promising pilot data and includes a diverse research team with substantial experience in exercise interventions, survivorship, and cancer control research. This grant will allow us to discern the efficacy of a novel, tailored, home-based aerobic and resistance exercise intervention for reducing CRF among prostate cancer patients during radiation, and to identify potential factors e.g., loss of strength, muscle atrophy, dysregulation of bodily immune function that may contribute to the development of CRF that, in turn, can be more effectively targeted through tailoring future exercise interventions to improve the impact of these exercise interventions on reducing CRF. These results will have the direct potential to reduce the suffering experienced by prostate cancer patients during radiation treatments, and to positively impact future research in exercise and cancer control on side effect management, the practice of evidence-based medicine for the treatment of CRF, and, eventually, public health policy and oncology practice. 