Swimming, water jogging, and aqua aerobics may provide health benefits to the general population as well as patients with chronic diseases. Research on the health benefits of aquatic exercise in comparison with activities such as running and walking is scarce, however. The goal of this study was to evaluate characteristics of participants in the Aerobics Center Longitudinal Study and to compare health habits and physiological characteristics among swimmers, runners, walkers, and sedentary women and men in order to evaluate the health benefits of swimming compared to other types of physical activity. Participants were 10,518 women and 35,185 men ages 20-88 years who completed a health examination during 1970 and 2005. Differences in the distribution of selected characteristics between swimmers and those participating in other types of activities (sedentary, runners, or walkers) were tested using logistics regression for proportion and ANOVA for continuous variables. The principal findings of this report are that swimming, as well as walking and running, has health benefits compared with a sedentary lifestyle.