The effect of exercise on cognitive function in people with multiple sclerosis: a systematic review and meta-analysis of randomized controlled trials

Objective A growing body of research examining the effect of exercise on cognitive function in people with multiple sclerosis (MS), while findings of available studies were conflicting. We aimed to explore the effect of exercise on cognitive function in MS patients. Methods For this systematic review and meta-analysis, we searched PubMed, Web of Science, EBSCO, Cochrane, and Scopus electronic databases, through July 18, 2022. Cochrane risk assessment tool was used to evaluate the methodological quality of the included literature. Results Twenty-one studies with a total of 23 experimental groups and 21 control groups met the inclusion criteria. There was a significant effect of exercise on improving cognitive function in MS patients, while the effect size was small (Cohen's d = 0.20, 95% CI 0.06–0.34, p < 0.001, I 2 = 39.31%). Subgroup analysis showed that exercise significantly improved memory (Cohen's d = 0.17, 95% CI 0.02–0.33, p = 0.03, I 2 = 7.59%). In addition, multicomponent training, exercise conducted 8 weeks and 10 weeks, up to 60 min per session, 3 times or more per week, 180 min or more per week increased cognitive function significantly. Furthermore, a worse basal MS status (defined by the Expanded Disability Status Scale) and an older age were associated with greater improvement in cognitive function. Conclusion MS patients are recommended to participate in at least three multicomponent training sessions per week, with each session lasting up to 60 min, and the exercise goal of 180 min per week can be achieved by increasing the frequency of exercise. Exercise lasting 8 or 10 weeks is best for cognitive function improvement. Additionally, a worse basal MS status, or the older the age, the greater effect on cognitive function.