Because of low fitness and heart problems, people with stroke are at very high risk of a second stroke or heart attack within 10 years. Exercise is a key treatment for heart and brain health. Although guidelines support the use of moderate intensity continuous aerobic training (MICT) to be used during stroke rehabilitation, it is often considered low priority by therapists. New research suggests that actually a more intense training method called High Intensity Interval Training, or HIIT, may be a “critical ingredient” for greater and more rapid recovery. HIIT uses short bursts of maximum training matched with brief recovery periods so that people can sustain higher aerobic levels than what is possible with MICT. HIIT also benefits the brain so could help people recover more. Whether HIIT could be used in the early phase of stroke (3 weeks to 3 months) especially among people with more severe weakness is not known. Since females are less likely to achieve independence after rehabilitation, there could also be sex and gender differences when testing such an approach.

The project will be the first to evaluate the longer term (three month follow-up) benefits of HIIT compared to MICT among subacute stroke survivors. Pilot data will be collected to see the whether stroke severity and sex/gender affects treatment response. It will be the first to examine whether there are benefits to both heart (fitness, walking capacity) and brain (using special brain imaging). By verifying safety, feasibility and protocol details, the study makes the first step towards an international multi-site trial amongst an expert team from Canada, Germany, and Australia.