Heterogeneity of Vascular Adaptations to Exercise With Aging in Women and Men

Inclusion Criteria: * Ability to provide consent; * Man or woman \>= 18 years; * Willing to be randomized to an exercise or control intervention; * No orthopedic limitations that would prevent the volunteer from performing treadmill or cycling exercise; * No use of hormone therapy in postmenopausal women or in men (note, hormonal contraceptives in premenopausal women will be allowed); * Healthy, as determined by medical history, physical examination, standard blood chemistries and ECG at rest and during a physician monitored graded exercise treadmill test; * Sedentary or recreationally active (\<2 days/wk vigorous activity); * No use of medications that might influence cardiovascular function (e.g., blood pressure and lipid lowering medications, metformin, insulin, sulfonylureas, etc.); * No use of vitamins, supplements or anti-inflammatory medications, or willing to stop 1 month prior to enrollment and for the duration of the study; Exclusion Criteria: * Contraindications to aerobic exercise; * Diabetic or fasted glucose \>126 mg/dL; * Resting blood pressure \>= 140/90 mmHg; * Current or past history of cancer other than skin cancer; * Preexisting or active cardiac, renal or hepatic disease; * History of stomach ulcer or bleeding or epilepsy or nervous system and/or seizure disorder; * Active or chronic infection; * An abnormal resting ECG, angina and/or ECG evidence of acute myocardial ischemia during the exercise test (development of ST-segment depression of more than 0.3 mV that is either horizontal, downsloping, or slowly upsloping- less than 1 mvolt/sec and lasts more than 0.08 sec; ST elevation; chest pain or discomfort), bundle branch block, AV block greater than first degree, arrhythmias; * Thyroid dysfunction, defined as ultrasensitive TSH \<0.5 or \>5 mU/L. Participants with abnormal TSH values will be reconsidered for participation after follow-up with their PCP and initiation of thyroid replacement medications for at least 3 months; * Smoking or tobacco use; * Alcohol consumption \> 14 drinks/week; * Body mass index \> 39kg/m2;