This study looks at how different levels of exercise can affect people with Parkinson's Disease (PD). **Parkinson's Disease** is a disorder that affects movement, often causing tremors. The study will include 30 participants who will exercise at two different levels. One group will do **Extensive Rehabilitation** (180 METs-min/week) and the other will do **Intensive Rehabilitation** (1350 METs-min/week). METs (Metabolic Equivalent of Task) is a measure of how much energy you use during exercise. The main goal is to see how exercise changes levels of a protein called **BDNF** (Brain-Derived Neurotrophic Factor) in the blood. BDNF is important for brain health. The study will also look at other factors like how exercise impacts movement, thinking, and brain activity using special scans like EEG (electroencephalogram) and fMRI (functional magnetic resonance imaging). **Key Points:** - Study lasts 4 weeks, with different exercise intensities for each group. - Participants need to be aged 30-80 years with PD, without severe health issues. - No compensation is mentioned, but participants get to contribute to important research. Participants should be ready to exercise regularly and meet specific health criteria to join.