THE INFLUENCE OF PHYSICAL-FITNESS AND EXERCISE UPON COGNITIVE-FUNCTIONING - A METAANALYSIS

Nearly 200 studies have examined the impact that either acute or long- term exercise has upon cognition. Subsets of these studies have been r eviewed using the traditional narrative method, and the common conclus ion has been that the results an mixed. Therefore, a more comprehensiv e review is needed that includes all available studies and that provid es a more objective and reproducible review process. Thus, a meta-anal ytic review was conducted that included all relevant studies with suff icient information for the calculation of effect size (N = 134). The o verall effect size was 0.25, suggesting that exercise has a small posi tive effect on cognition. Examination of the moderator variables indic ated that characteristics related to the exercise paradigm, the partic ipants, the cognitive tests, and the quality of the study influence ef fect size. However, the most important finding was that as experimenta l rigor decreased, effect size increased. Therefore, more studies need to be conducted that emphasize experimental rigor.