Self-regulation, self-control, and executive functioning are umbrella constructs that encompass processes involved in exerting control over cognitive and behavioral processes. Self-regulation was described as an ability reflecting mature cognition: Mature cognition is characterized by abilities that include being able: (a) to hold information in mind, including complicated representational structures, to mentally manipulate that information and to act on the basis of it, (b) to act on the basis of choice rather than impulse, exercising self-control (or self-regulation) by resisting inappropriate behaviors and responding appropriately, and (c) to quickly and flexibly adapt behavior to changing situations. These abilities are referred to respectively as working memory, inhibition, and cognitive flexibility. Together they are key components of both "cognitive control" and "executive functions..." Some researchers have proposed an integrative framework of self-regulation than encompasses executive functions and self-control. Thus, in this proposal, we have adopted such an integrative framework whereby self-regulation encompasses executive functions, self-control, and other sub-processes. As noted in the specific aims, our meta-analysis and narrative review examining the impact of 28 physical activity (PA) and exercise interventions on EF outcomes in healthy children reported that the targets often shown to improve after exercise were attention, working memory, inhibition, and cognitive flexibility, and preliminary research suggests the strongest effects are on attention and inhibition. The goal of this project is to develop an assay to examine engagement of attention and inhibitory control across several rigorously controlled exercise conditions. This proposal is built on an integrative framework whereby self-regulation encompasses executive functions (EF), self-control, and other sub-processes. Although there is a growing awareness of the benefits of exercise on self-regulatory processes in children including EF, there are still many critical gaps in the research. A recent publication which is a meta-analysis and narrative review examining the impact of 28 physical activity and exercise interventions on EF outcomes in healthy children that highlights some of these gaps. Although earlier results showed that interventions had a significant, small to moderate positive effect on EF, the effects varied widely across studies. This research informed this application in several ways. First, no study demonstrated how or why the interventions improved EF outcomes. Additionally, the behavioral assays or measures varied widely targeting numerous components of EF. The EF targets most often shown to improve after exercise were attention, working memory, inhibition, and cognitive flexibility (each improved in at least five of the included studies). These findings are consistent with recent work at the UC Irvine Pediatric Exercise and Genomics Research Center (PERC); in studies with healthy children and children with special needs, improvements were found after exercise in all four components. Few, if any, studies have been able to demonstrate empirically why participants exhibit improvements in EF after exercise, and studies have not yet demonstrated engagement of EF during exercise. Thus, there is a need to understand why exercise seems to improve these targets. However, the tools used in exercise research to date are limited. Many have been adopted from developmental or educational research, rather than developed specifically to test targets in exercise research; our search yielded only one published measure of self-regulation (cognitive, affective, and motor self-regulation) that has been administered during physical activity. This proposal begins to address these gaps in the literature, by focusing on the development of an assay for important EF targets are improved through exercise and by testing engagement of these targets during exercise of varying intensity