High-intensity Interval Circuit Training in People With Parkinson Disease

Inclusion Criteria: * diagnosis of Parkinson's disease * Hoehn and Yahr level of 1 to 3 * ability to walk independently with or without an assistive device * obtain medical clearance to participate in moderate or vigorous exercise. Exclusion Criteria: * diagnosis of any neurological disease other than PD (including but not limited to stroke, dementia, and multiple sclerosis; mild cognitive impairment is not excluded) * bone instability (non-consolidated fractures, unstable spinal column, severe osteoporosis) * muscle or ligament tears * uncontrolled hypertension * uncontrolled diabetes * severe cardiovascular disease that impairs walking or exercise * a major change in medication during the study training period (pre-test to post-test)