We discuss the factors that encouraged us to examine the question of whether exercise training has a positive influence on cognitive health of older adults in 2003. At that time there was a substantial literature on exercise and cognition. However, cognitive assessment instruments, exercise protocols (including type of exercise, length, and intensity of exercise programs), and subject-selection criteria differed widely. Our meta-analysis enabled us to examine both the main question under study-exercise effects on cognition-and potential moderators of this effect. Several interesting findings, which are briefly detailed in the present article, were revealed by our analyses. The current article also examines where the literature has gone since our 2003 article.