PROJECT SUMMARY Few behaviors inadequate development, are Pitfalls behaviors this movement child and Behavior of Finally, randomized Hour didactic, populations (Training and these and candidate ultimately young children meet the recently adopted World Health Organization recommendations for movement (physica activity, sleep, and screen-time), known as the 24-Hour Movement Guidelines. This balance of movement behaviors places children at risk for more behavioral problems, poor cognitive delayed motor skills, and obesity. Minority children and children who live in low-income household at increased risk of meeting ew recommendations, and consequently these long-term health outcomes. of current literature include focusing on one behavior at a time and neglecting the context in which these occur. Ecological momentary assessment (EMA) and mHealth tools are ideally positioned to address gap, by assessing and addressing movement behaviors in real-time and within the home, where all three behaviors occur. Using mixed methods, this study aims to identify patterns (amount and context) of movement behaviors within the home via EMA paired with a child-worn accelerometer and identify barriers facilitators to changing these behaviors within the home via semi-structured interviews (Research Aim 1). change theory, previous literature, and an iterative process using parent feedback will inform the design a movement behavior intervention delivered through a mHealth modality e.g., mobile app, Research Aim 2). this study will then pilot test the preliminary effectiveness and feasibility of this intervention n a control trial with the goal of meeting all three movement behavior recommendations, t hus the 24- Movement Guidelines (Research Aim 3). To complement these research aims, the candidate will receive hands-on, and applied research training i n EMA, mHealth, and interventional research amongst diverse (Training Aim 1), along with behavior change theory and child behavior and cognitive development Aim 2). The candidate will expand her network and presence, and scientific prowess in writing grants mentoring to propel her into a future career as a 24-Hour Movement expert (Training Aim 3). Experts in respective fields, who are also seasoned mentors, will guide her t hrough these research and training aims, ultimately into an independen position and research career. This experience will culminate in data for the to build her independent research program, with the goal of improving child movement behaviors, and their long-term health. l f ( i t