The objective of this project is to study the cerebrovascular response to a single bout of high intensity interval exercise (HIIT) in 25 individuals with chronic stroke compared to 25 age- and sex- matched healthy controls (CON). We will enroll 25 young healthy adults (CONyoung) as a reference group. Our hypothesis is that the cerebrovascular response in individuals with chronic stroke will be significantly lower: 1) during a single bout of HIIT, and 2) during the recovery immediately following and 30 minutes after HIIT, compared to CON.

This study has 2 visits at the University of Kansas Medical Center Research in Exercise and Cardiovascular Health Laboratory. For the first visit, we will perform questionnaires about heart health, physical activity and overall health. Participants will then complete a submaximal exercise test on a seated stepper. Participants will also have a familiarization session to practice HIIT. The second visit will include cerebrovascular measures before, during, immediately after, and 30 minutes after performing HIIT.

Chronic Stroke Inclusion Criteria:

• Age 40-80 years old
• Treated for stroke 6 months to 5 years ago
• Performs <150 minutes of moderate intensity exercise per week
• Able to answer consenting questions and follow a 2-step command

Chronic Stroke Exclusion Criteria:

• Stroke etiology due to COVID-19 pathology.
• Symptoms of COVID-19 and/or Positive COVID-19 test within the past 3 months
• Unable to stand from a sitting position without physical assistance
• Recent joint replacement/surgery/poor motor control that limits ability to perform exercise on a recumbent stepper
• Insulin injection dependent diabetes
• Dependent on supplementary oxygen
• History of other neurological disease (Multiple Sclerosis, Alzheimer's disease, Parkinson's disease)
• Unable to find TCD signal on the stroke-affected or non-affected MCA.

CON Inclusion Criteria:

• Matched age ± 5 years to participant with chronic stroke
• Matched sex to participant with chronic stroke
• Performs <150 minutes of moderate intensity exercise per week
• Able to answer consenting questions and follow a 2-step command

CON Exclusion Criteria:

• Symptoms of COVID-19 and/or Positive COVID-19 test within the past 3 months
• Unable to stand from a sitting position without physical assistance
• Recent joint replacement/surgery/poor motor control that limits ability to perform exercise on a recumbent stepper
• Insulin injection dependent diabetes
• Dependent on supplementary oxygen
• History of other neurological disease (Multiple Sclerosis, Alzheimer's disease, Parkinson's disease)
• Unable to find TCD signal on the right or left MCA.

CONyoung Inclusion Criteria:

• Age 18-30 years old
• Low cardiac risk (defined by the American College of Sports Medicine)
• Able to find TCD signal on the right or left MCA

We will recruit individuals with chronic stroke, age- and sex-matched controls (CON) and young healthy controls (CONyoung) within the community.