A diagnosis of autism spectrum disorder (ASD) and stereotypy engagement is associated with reduced physical activity (PA). Beyond health benefits, researchers have also reported decreases in stereotypy and corresponding increases in on‐task behavior in individuals with ASD following PA. However, the duration of reported PA varies among studies examining these effects and the persistence of any effect is not well understood. Furthermore, no previous study examining these effects has reported difficulty evoking adequate durations of PA. The purposes of this study were to (1) develop an intervention to increase PA engagement, (2) analyze changes in stereotypy and on‐task behavior following PA, and (3) assess persistence of changes as a function of PA duration. Four participants with ASD were observed for 10 min before, between 1 and 15 min during, and 30 min following PA. Results demonstrated that some duration of PA decreased stereotypy and increased on‐task behavior for most participants.