Regular Swimming, Vascular Function, and Arthritis

Hypothesis #1: The investigators hypothesize that both swimming training and cycling training will demonstrate significant improvements in endothelium-mediated vasodilation and central artery compliance in this population and that there will be no difference in the magnitude of increases between the water-based and land-based exercise interventions. Hypothesis #2: The investigators hypothesize that the improvements in endothelium-dependent vasodilation and arterial compliance in response to exercise training interventions will be related to the corresponding reductions in inflammatory biomarkers. Hypothesis #3: The investigators hypothesize that both swimming exercise and cycling exercise will improve functional capacities and disease progression in middle-aged and older adults with osteoarthritis.