1. A diagnosis of Parkinson's Diseas within the last 3 years.
2. Hoehn and Yahr stage less than 3
3. Age 40-80 years

1. Currently being treated with PD medications 
2. Expected to require treatment with medication for PD in the first 6 months of the study.

3. Presence of known cardiovascular, metabolic, or renal disease or individuals with major signs or symptoms suggestive of cardiovascular, metabolic, or renal disease without medical clearance to participate in the exercise program.
4. Uncontrolled hypertension (resting blood pressure >150/90 mmHg)
5. Hypothyroidism (TSH >6.0 mU/L), abnormal liver function (AST or ALT more than 2 times the upper limit of normal), abnormal renal function (estimated glomerular filtration rate (eGFR) using the MDRD4 equation or the CKD-EPI equation <45mL/min/1.73m2 ).
6. Serious illness (requiring systemic treatment and/or hospitalization) within the last 4 weeks.
7. Individuals who have been exercising at greater than moderate intensity for 120 minutes or more per week consistently over the last 6 months will be excluded. 
8. Known allergy to iodinated products.
9. (For women only) Actively breast-feeding an infant, and/or pregnant, or plan to become pregnant in the next 12 months.
10. Other disorders, injuries, diseases, or conditions that might interfere with ability to perform endurance exercises (e.g. history of stroke, respiratory problems, traumatic brain injury, orthopedic injury, or neuromuscular disease).