In this paper we review the literature that has examined the nature and strength of the relation between physical fitness and cognitive performance in old age. We consider both cross-sectional studies, which have investigated differences in cognitive performance between discrete groups of high- and low- fit older adults, and training studies, which have examined the effect of exercise training regimens on cognitive performance. We do not consider the acute or short-term effects of a single bout of physical activity on cognitive performance. These data have been reviewed elsewhere  and are beyond the scope of this manuscript. Studies that examine the acute effects of a single bout of exercise stress are discussed only when they contribute directly to our understanding of general principles underlying the relationship between physical fitness and cognitive performance.
Exercise and Sports Science Review, v. 22, issue 1, p. 195-220
Available at: http://works.bepress.com/kathleen_moore/45/