Role of Microvascular Insulin Resistance and Cardiorespiratory Fitness Diabetes

This study is investigating the relationship between insulin resistance in tiny blood vessels (microvascular insulin resistance), cardiorespiratory fitness, and Type 2 diabetes. Researchers want to understand whether reduced fitness is a cause or consequence of insulin resistance, which could lead to better exercise-based treatments for diabetes prevention. **You may be eligible if...** - You are a sedentary adult (less than 1 hour of physical activity per week) - Your BMI is between 25 and 40 - You have Type 2 diabetes, OR you do not have diabetes (both groups are being studied) **You may NOT be eligible if...** - You have heart disease, lung disease, or asthma - You have uncontrolled high blood pressure - You have nerve damage in your limbs (peripheral neuropathy) - You take beta blockers, calcium channel blockers, or other medications that interfere with exercise testing - You have a physical condition that limits your ability to exercise Talk to your doctor to see if this trial is right for you.