 The growing population of obese adults is predicted to create a large public health burden in the next few decades. Obese humans also exhibit reduced exercise capacity and lower muscle blood flow. The overall goal of this research program is to investigate the obesity-related changes in microvascular function contributing to impaired muscle blood flow. This proposal seeks to directly test vascular control in human skeletal muscle resistance arteries in exercising humans. The investigators propose to study younger obese adults, without confounding effects of age, metabolic syndrome, or diabetes-before the negative effects of obesity can exert their full negative impact. The general hypothesis is that endothelium dependent dilation EDD and functional exercise vasodilation is impaired via shift away from nitric oxide bioavailability and a shift toward increased reliance on potassium K mediated vasodilation. 