The effect of exercise intensity and dose on cognitive function in a post-stroke population: a systematic review and meta-analysis

Background: Research indicates that aerobic exercise can enhance cognitive activity after stroke, however the optimal parameters of exercise for cognitive function after stroke are largely unknown.Objectives: The present systematic review and meta-analysis aimed to determine whether exercise intensity and dose had an impact on cognitive improvement after stroke. No review to date has focused on the effects of exercise intensity and dose on cognitive function in a stroke population.Methods: Five databases (OVID Medline, CINAHL, SPORTDiscus, PsycINFO, and Scopus) were searched for eligible studies.Results: Thirteen studies (11 high quality; 1 moderate; 1 poor), representing data from 551 survivors met inclusion criteria, including ten long-term and three acute exercise interventions. Moderate-intensity exercise programmes of at least 8 weeks duration significantly improved attention, executive function, working memory, memory, speed of processing, intelligence, and visuospatial function. Interventions less than 8 weeks did not report significant improvements in working memory. There was no evidence that higher intensity or dose elicited greater cognitive improvements. However, considerable heterogeneity existed regarding exercise characteristics and cognitive measures used across studies. The meta-analysis indicated that aerobic exercise did not affect processing speed, set shifting, or working memory.Conclusions: Based on the novel findings of this review, exercise rehabilitation post-stroke should aim to achieve a minimum dose of at least eight weeks of moderate-intensity aerobic exercise to improve cognitive function.