The "Healthy Heart Race" activity provides a hands-on demonstration of cardiovascular function suitable for lay audiences. It was field tested during the United States of America Science and Engineering Festival held in Washington, DC, in October 2010. The basic equipment for the activity consisted of lengths of plastic tubing, a hand pump, collection containers, clamps, and simulated blood prepared by tinting water with red food coloring. Student participants were first asked to experience the effort required to pump through an unaltered tube. A presenter then applied a strong clamp that pinched each tube downstream from the pump, and students were asked to pump against the increased resistance. The students' observations were then used as the basis for discussions of atherosclerosis and coronary heart disease with the presenters. Distribution of informative postcards during the 2 days of the festival indicated that at least 2,500 students completed the Healthy Heart Race activity. Our experiences to date suggest that the Healthy Heart Race activity can be accomplished effectively in the high-volume, high-distraction environment of a science fair or museum. (Contains 3 figures and 1 table.)