Background/Aims: Stroke and dementia share a similar pathophysiology and exhibit a reciprocal relationship.1 Consequently, there is currently a global prioritisation agenda for more personalized and specific exercise recommendations for these pathologies.2 Therefore, this systematic review aimed to determine 1) optimal training parameters of high-intensity aerobic exercise to improve cognition in people with stroke or dementia, 2) overlap in training parameters between pathologies, and 3) safety in implementing these interventions.
Methods: We systematically searched six electronic databases from inception to February 2025. We included randomised and non-randomised interventions assessing changes in cognition after high-intensity aerobic interventions in adults with stroke or dementia. We categorised high-intensity aerobic exercise according to the prescribed percentages of heart rate maximum (HRmax) developed by the American College of Sports Medicine: “Bottom high-intensity” (i.e., 77-86% HRmax), “Middle high-intensity” (i.e., >85-95% HRmax), and “Top high-intensity” (i.e., ≥96% HRmax).
Results: Twenty-two studies were included in the review (n=13 stroke). Fourteen (64%) studies demonstrated significant cognitive improvement following high-intensity aerobic exercise. Fifteen (68%) of studies reported adverse events of varying severity. Middle high-intensity aerobic exercise appears to facilitate the most consistent improvement in cognitive outcomes, without increasing risk of adverse events. Eleven (50%) studies did not report an exercise prescription parameter, making reproducibility impossible.
Conclusion: There remains an urgent need for better reporting of exercise intervention parameters and adequately powered comparator trials. However, our review suggests that middle high-intensity may be the most useful and safest high-intensity option in people living with stroke or dementia.