High-intensity interval training after stroke: evidence & practice

PURPOSE: To synthesize clinical, cognitive, safety, and mechanistic evidence on supervised high-intensity interval training (HIIT) after stroke and translate key findings into practice. METHODS: We conducted a narrative review of supervised HIIT interventions in adults after stroke. Electronic searches of PubMed and Web of Science identified studies published between January 1, 2014, and September 30, 2025. Eligibility criteria emphasized feasibility, safety, and neurofunctional outcomes (six-min walk distance, gait speed, peak aerobic capacity, activities/participation, and cognition). Quantitative pooling was not performed, and the findings were qualitatively synthesized. To explain biological plausibility, mechanistic and translational sources were reviewed irrespective of the year and summarized separately. RESULTS: HIIT was feasible under guideline-concordant screening and monitoring, with no serious adverse events. Consistent gains were observed in aerobic capacity, walking endurance, and usual gait speed, whereas activity/participation effects were mixed. Cognitive benefits were domain-specific and the clearest for executive functions. Mechanistic signals (e.g., brain-derived neurotrophic factor (BDNF), frontal oxygenation, and endothelial function) support biological plausibility. CONCLUSION: Supervised HIIT appears safe and clinically useful for augmenting locomotor and aerobic outcomes after stroke and may preferentially enhance executive cognition. Implementation should complement task-specific therapy and follow standard screening and monitoring procedures. Future work should refine dose- and phase-specific protocols to maximize application to daily function.