Purpose: The purpose of this feasibility study was to provide an opportunity to increase physical activity (PA) and heart rate (HR) for children with Down syndrome (DS) during unstructured group exercise utilizing a riding device called the Power Pumper®. Method: Twenty-four children aged 5 to 7 years old participated in this case-control study, including 12 children with DS and 12 children without DS. Those without DS participated as age-matched controls. A 30-min unstructured PA session utilizing the Power Pumper was provided to both groups on 2 occasions. HR and PA were measured at baseline and during both sessions. Results: For children with DS, findings revealed a statistically significant increase in time spent in moderate-to-vigorous PA (MVPA), F(1, 15) = 16.503, p < 0.010, ES = 0.76, and a nonsignificant increase in HR (ES = 0.41) when comparing exercise session performance to baseline. For children without DS, findings revealed statistically significant increases in time spent in MVPA, F(1, 15) = 73.604, p < 0.010, ES = 0.94, and HR, F(1, 22) = 34.634, p < 0.010, ES = 0.69, between exercise and baseline. Total MVPA approached the recommended 60 min following device use. PA and HR differences between baseline and exercise were greater in magnitude for children without DS. Conclusion: By participating in unstructured exercise in a social environment using the Power Pumper, children with DS engaged in higher-intensity PA accompanied by a nonsignificant physiological response in HR. These outcomes support PA guidelines recommended by the National Association for Sport and Physical Education. This device supports 1 option for achieving 60 min of MVPA daily.