This study investigates the effects of endurance treadmill exercise on Parkinson's disease. Participants will be in the study for 12 months. The purpose of this study is to see if high-intensity exercise can slow down the progression of Parkinson's disease symptoms in people who have not started medication for the disease.

Participants will be randomly assigned to one of two study arms: one group will exercise at 60-65% of their maximum heart rate, and the other at 80-85%. They will exercise four times a week. The study will measure changes in movement, walking ability, daily activity, cognition, quality of life, and fitness. Participants will be observed at 12 and 18 months to gather data.

• Who can participate: Adults aged 40-80 with early-stage Parkinson's disease, who have not started Parkinson's medication, may participate. Key factors include a positive DaTscan™ SPECT and a disease duration of less than 3 years.
• Study details: Participants will engage in treadmill exercise sessions four times per week. They will be monitored for changes in their condition and fitness levels.
• Study timelines: The study will last 12 months.