Cardiovascular disease is the leading cause of death in the United States. Flow-mediated dilation (FMD) has been used as a non-invasive method of evaluating endothelial function and FMD is used as a marker for cardiovascular disease. It has been shown that the blood flow response during exercise is what improves FMD. Compression therapy has been hypothesized to have a blood flow response similar to that of exercise. Exercise has been shown to improve FMD and it is hypothesized that compression therapy will improve FMD.The purpose of this study is to measure blood flow velocity during exercise and compression therapy and flow-mediated dilation (FMD) before and after a single bout of exercise and compression therapy in people who smoke.Methods: Subjects were smokers age 22.5 +/- 2.56 years, smoked a pack of cigarettes or more a week, were relatively healthy, and not involved in any form of lower body training. There were 3 sessions where FMD was measured pre and post treatment (exercise, compression therapy, and time control) using a high-resolution ultrasound. Blood flow velocity was measured during treatment of exercise and compression therapy also using a high-resolution ultrasound. Blood flow velocities and arterial diameters for FMD were collected and analyzed using advanced computer software.Results: Exercise showed a higher total blood flow over time compared to baseline while compression therapy showed no difference in total blood flow when compared to baseline. Peak velocity averages were higher in exercise (~9 fold) and compression therapy (~3 fold) than baseline. There were no significant differences in FMD within or between treatments in this study.Conclusion: Further research with different exercise method and higher pressures from compression device is needed to compare blood flow response and FMD changes with exercise and compression therapy.