The heart and brain are regulated by the autonomic nervous system. Control of these organs can be disrupted in people with spinal cord injury (SCI). This may affect their ability to regulate blood pressure during daily activities and process the high-level information. Previous studies show that high-intensity exercise induces better outcomes on heart and information processing ability in non-injured people compared to moderate-intensity exercise. However, it is unknown the effects of high-intensity exercise on heart and brain function in people with SCI. Therefore, this study aims to examine the effects of a single bout of high-intensity interval training on heart and brain function in this people with SCI compared to age- and sex-matched non-injured controls.

This study will be a cohort control study involving two groups: individuals with SCI, whose level of injury is at the 6th thoracic vertebra or above, and age- and sex-matched controls. Eligible participants will be asked to visit the Laboratory located at 115 Kimball Tower, University at Buffalo South Campus, twice. The first visit takes up to 3 hours, and the second visit takes up to 5 hours.

Inclusion Criteria:

1. Diagnosed with a traumatic or non-traumatic spinal cord injury and have ≥4/5 strength in at least one cervical 5 myotome (elbow flexors), allowing to utilize the arm ergometer and level of injury at or above the 6th thoracic vertebra
2. Classified as A, B, C, D (motor and sensory complete or incomplete) on the American Spinal Injury Association (ASIA) Impairment Scale (AIS)
3. Longer than 6 months post the onset of injury and have been discharged to the community from inpatient rehabilitation prior to enrollment
4. English is the first language
5. At least one of the cerebral arteries (i.e., middle cerebral artery and/or posterior cerebral artery) can be found via transcranial Doppler

Exclusion Criteria:

1. Medical conditions that preclude exercise, such as unstable angina, uncontrolled arrhythmias, a recent history of congestive heart failure that has not been evaluated and effectively treated, severe valvular disease, uncontrolled hypertension (i.e., resting systolic blood pressure ≥ 160 mmHg and/or diastolic blood pressure ≥ 105 mmHg)
2. Moderate-severe traumatic brain injury
3. Diabetes
4. Color blindness
5. Pre-existing shoulder injuries
6. Pregnancy

This study will include people with SCI with level of injury T6 or above and age- and sex-matched non-injured controls.