Role of Aging and Individual Variation in Exercise Training Responsiveness

Inclusion Criteria: * Individuals who completed participation in the STRRIDE-PD trial (NCT00962962) * Body Mass Index (BMI) \> 18 and \< 45 kg/m2 * Stable dose (≥1 month) of any cardiometabolic medications Exclusion Criteria: * Poor vein access * Current use of tobacco or any nicotine products, including e-cigarettes * Insulin-dependent diabetes * Active untreated hypothyroidism with thyroid stimulating hormone (TSH) concentrations \> 10.0 uIU/mL * Systemic inflammatory or connective tissue disease, chronic infectious disease, chronic pulmonary disease or symptomatic cardiovascular disease with positive functional study by ECG or imaging * Current, actively treated malignancy other than dermatologic conditions * Absolute contraindications to exercise testing: ongoing unstable angina; uncontrolled cardiac arrhythmia with hemodynamic compromise; active endocarditis; symptomatic severe aortic stenosis; decompensated heart failure; acute pulmonary embolism, pulmonary infarction, or deep vein thrombosis; acute myocarditis or pericarditis; acute aortic dissection; physical disability that precludes safe and adequate testing * Relative contraindications to exercise testing: known obstructive left main coronary artery stenosis; moderate to severe aortic stenosis with uncertain relation to symptoms; tachyarrhythmias with uncontrolled ventricular rates; acquired advanced or complete heart block; hypertrophic obstructive cardiomyopathy with severe resting gradient; recent stroke or t…