Background: Stroke is the second leading cause of death and disability worldwide and in Hong Kong, 6.2% of all registered deaths in 2020 were due to cerebrovascular disease. Exercise training has the potential to improve the deconditioned hemodynamic, motor, and cognitive functions associated with stroke. Purpose: The proposed study seeks to investigate the effects of AET on the large intracranial and extracranial cerebral arteries' morphological and haemodynamic features and the cognitive and motor functions in post-stroke chronic patients. Additionally, the study seeks to compare the cerebral arteries' features between post-stroke patients and age-matched controls without stroke. Furthermore, the project seeks to assess the association between the cerebrovascular system changes and the cognitive and motor function changes in post-stroke patients undergoing AET. Study

Design: A Randomised controlled trial (RCT) in which the post-stroke patients will be randomly assigned into three groups consisting of a control group and two AET interventional groups (treadmill and cycle ergometer). Each group will target sample size of 20 participants. The target dosage for the two AET modes will consist of 1.) a session duration=30mins, 2.) frequency=3times/week, 3.) high intensity=(60-84% heart rate reserve (HHR).4.) Types=Treadmill and cycle ergometer 5.) overall program duration=3months. Data collection methods: Quantitative data on the cerebral arteries' haemodynamic and morphological features will be assessed using duplex carotid ultrasound (DCUS) and transcranial Doppler (TCD) ultrasound techniques. Montreal cognitive assessment (HK) version and six-minute walk test (6MWT) will assess cognitive and motor functions respectively. The data will be assessed at three time periods of during the 3 months AET program Significance of the study: The study has the potential to inform the clinical decision making process on the usefulness of AET in improving post-stroke chronic patients. Results on associations will provide a basis for future work in chronic stroke Rehabilitation functional outcome prediction models based on DCUS and TCD ultrasound imaging techniques.