Technical Justification for Physical Fitness Intervention: The beneficial effects of physical fitness on cognitive performance and brain health have been documented in many studies. For example, this literature suggests that increased exercise leads to the birth of new neurons in the hippocampus (a key brain region underlying Gf), increased connections among neurons throughout the brain, the development of new vasculature structure, increased production of neurotrophic proteins, enhanced learning and memory, and enhanced executive control including attention and inhibition, working memory, mental flexibility, and action monitoring. In particular, (1) exercise effects are largest for tasks that involve executive control functions for working memory, planning, and problem solving - abilities that are essential for Gf and ARP; and (2) aerobic exercise training, when combined with strength and flexibility training, had a greater positive effect on cognition compared to exercise training programs that included only aerobic components. Such findings provide important justification for the physical activity intervention proposed here. Hence, the proposed fitness intervention employs a combined aerobic/resistance training program to further enhance the benefits of cognitive training on Gf and ARP.