Physical Activity and Cognitive Function: A Review of Contemporary Meta-Analyses

The purpose of the present manuscript is to review the current meta-analytical studies focusing on physical activity and cognitive functions, and to examine these meta-analyses based on their characteristics and moderators. Studies were searched and filtered systematically from four English databases and two Chinese databases. Then, included researches were coded and analyzed via visual inspection based on their descriptions, participants, physical activities, cognition, and other moderators. The results indicated that there were nine related contemporary meta-analyses, and the majority of which demonstrated that physical activity benefits overall cognitive function. Only two showed negative or partially negative results. The positive results were mostly A-grade with respect to the grade of recommendation, and had a higher category in levels of evidence as well as satisfying the criteria of causal evidence. However, in terms of studies using a meta-analytical approach, conditions of constructing exercise prescriptions, dose-response gradients, and biologic plausibility are yet insufficient. Overall, physical activity has positive effects on cognitive function. The conclusion is further supported by several research qualitative and quantitative indices, such as grades of recommendation, levels of evidence, and numerous criteria of causal evidence. Nevertheless, detailed sub-categories remain unclear. Problems and questions yet to be solved can be pinpointed in the future research.