The purpose of this study is to learn more about how common lifestyle interventions, such as exercise, affect how our brains respond to performing thinking tasks and to viewing pictures of foods and various other objects. The investigators are also interested in how changes in hormones that might be different in men and women could affect how lifestyle interventions change these brain responses. This will help us to better understand how different lifestyle interventions affect the brain and how this might relate to various behaviors. Eligible participants will be asked to complete 2 study days before and again after a 12-week intervention period, during which they will either continue with usual activities or be asked to complete exercise sessions four times per week. They will be randomly assigned to one of these conditions (exercise or not) and will not be able to choose their group assignment.
