<qa>  What is the goal of this research?The purpose of this project is to examine the effects of an acute bout of exercise on childrens energy intake over the course of a day. Previous studies in adolescents and adults have shown exercise to be effective in decreasing short-term energy intake, with some variability. Individual characteristics such as habitual physical activity and psychological factors may influence the effect of exercise on energy intake, but these factors have yet to be examined. The investigators have assembled a multi-disciplinary team of researchers, with expertise in eating behavior, exercise, psychology, and clinical research in order to examine these questions. First, the investigators will examine the difference in energy intake at lunch, snack, and dinner meals in response to 30 minutes of imposed exercise compared to 30 minutes of rest. Second, the investigators will collect objective measures of childrens habitual physical activity, child characteristics body composition, eating behavior traits, and individual responses to the controlled exercise bout. The investigators can then examine both group and individual differences in the energy intake response to exercise. Twenty children ages 9-12 will be tested over the course of three visits. The key outcome will be differences in energy intake in response to exercise vs. rest. Secondary outcomes include the influence of differences in habitual physical activity, personal characteristics, and responses to the exercise bout on childrens energy intake. The long term goal of this line of research is to understand the mechanisms behind the interaction between exercise and energy intake. The translational potential of this research will be to inform personalized childhood obesity prevention strategies in children at risk for overweight. 