Exercise Therapy and Radiation Therapy (EXERT) for Metastatic Prostate Cancer

This study tests whether adding a structured exercise program alongside stereotactic body radiation therapy (a precise form of radiation delivered in 5 sessions) can improve outcomes for men with metastatic prostate cancer. **You may be eligible if...** - You are a male 18 or older with prostate cancer that has spread to lymph nodes or other parts of the body - You are receiving or planned to receive stereotactic body radiation therapy (5 fractions) - You speak and read English fluently - You are physically able to perform some level of exercise - Your radiation oncologist approves your participation **You may NOT be eligible if...** - You already exercise more than 90 minutes per week - You have a medical reason that prevents you from exercising - You have significant heart problems (Class II-IV heart failure, recent heart attack or stenting within 6 months, uncontrolled irregular heartbeat) - You have other serious conditions like blood clots, pulmonary embolism, or respiratory failure Talk to your doctor to see if this trial is right for you.