A growing body of research also demonstrates the beneficial effects of cognitive training in later life to promote a healthy brain. For example, researchers demonstrated cognitive interventions targeting memory, reasoning and speed of processing were effective to improve brain function. Unfortunately, despite these promising findings, the generalizability of cognitive training is limited. For example, researchers showed cognitive training tasks designed to improve reasoning, memory, planning, spatial skills and attention in over 11,000 participants demonstrated no transfer effects to untrained tasks, even when the tasks were closely related. The purpose of this study is to see if combing aerobic exercise and cognitive training can enhance the cognitive improvement of each. Specially, the investigators wish to determine if aerobic exercise done immediately before cognitive training can potentiate the improvement.