My research is primarily focused on understanding the effects of physical activity on the cardiovascular system. We use exercise training to investigate the effects of high levels of physical activity, while aging and spaceflight (simulated and actual) are used to model lower levels of physical activity. According to the American Heart Association, physical inactivity is a major risk factor for developing coronary artery disease, stroke and peripheral vascular disorders. It also contributes to other risk factors, including obesity, high blood pressure, low levels of HDL cholesterol, and diabetes.