Near Infrared Spectroscopy (NIRS) as a Method for Measuring Oxidative Capacity of Skeletal Muscle Mitochondria in Breast Cancer and All Gynecological Cancer Patients

This study is testing a non-invasive light-based technique called Near Infrared Spectroscopy (NIRS) to measure how well the muscles' power plants (mitochondria) are working in breast and gynecological cancer patients. Poor mitochondrial function is linked to cancer-related fatigue and reduced treatment tolerance. **You may be eligible if...** - You have been diagnosed with breast cancer or a gynecological cancer (such as ovarian, cervical, or uterine cancer) without distant spread - You can perform light cycling exercise for up to 15 minutes - Your blood counts (hemoglobin, liver enzymes) are within acceptable ranges - You have a moderate baseline level of physical activity **You may NOT be eligible if...** - Your cancer has spread to other parts of the body (metastatic) - You have significant heart or lung disease - You require continuous oxygen - You have a large amount of body fat under the skin that would interfere with the light sensor readings Talk to your doctor to see if this trial is right for you.