Age-related changes in the brain can compromise cognitive function. However, in some cases, the brain is able to functionally reorganize to compensate for some of this loss. The present paper reviews the benefits of exercise on executive functions in older adults and discusses a potential mechanism through which exercise may change the way the brain processes information for better cognitive outcomes. Specifically, older adults who are more physically active demonstrate a shift toward local neural processing that is associated with better executive functions. We discuss the use of neural complexity as a sensitive measure of the neural network plasticity that is enhanced through exercise. We conclude by highlighting the future work needed to improve exercise prescriptions that help older adults maintain their cognitive and physical functions for longer into their lifespan.