Brief Title: Aerobic Training on Cerebrovascular Function, Cognition and Gait in Parkinson's Disease

This randomized controlled trial will investigate the effects of a 12-week supervised aerobic training program on cerebrovascular function, peripheral vascular health, cardiovascular autonomic modulation, cognition, non-motor symptoms, sleep, mood, gait biomechanics, quality of life, and body composition in patients with Parkinson's disease (Hoehn \& Yahr stages 1-3). Participants will be randomly allocated to aerobic training or usual care.