Inclusion Criteria:  Otherwise healthy older adults 65-75 years of age with normal lung function; men 30< %body fat ≤50 and women 35< %body fat ≤55; and ability to perform pulmonary and exercise test. Other inclusion criteria include the following: Nonsmokers who have no history of smoking No personal history of significant mental illness No weight loss dietary restrictions No current or past history of significant substance or alcohol abuse No history, evidence, or uncontrolled symptoms of heart disease No history of uncontrolled hypertension No current medications that may interfere with exercise capacity No recent history or indication of asthma No musculoskeletal abnormality that would preclude exercise No documented sleep disorders (e.g., SDB &/or sleep apnea) No serious health conditions that would preclude study goals or participation in exercise (per PI & medical staff & preliminary or follow up testing; including significant other diseases, occult asthma, prior surgeries-especial lung or abdominal, or history of chemotherapy that could affect lung or heart function) No metabolic disorders (e.g., diabetes). Only postmenopausal women will be included. Women on hormone replacement therapy will be allowed to participate if the dosage remains similar during the entire protocol.  Exclusion Criteria:  Volunteers with a mMRC score of 3 or 4 will be excluded due to likeliness of underlying disease. Individuals participating in regular vigorous conditioning exercise such as running, jogging, aerobics, cycling, or swimming more than two times per week will be excluded. However, if subjects have an exceedingly high exercise capacity (greater than 2 SD of predicted), they will be excluded. Maximal cycle ergometry test will be used to determine if further participation in testing is appropriate for the participant (e.g., normal exercise test, exclude presence of provokable ECG changes suggestive of heart disease, or dangerous arrhythmias or exercise induced hypertension or bronchoconstriction. If the participant develops an abnormal ECG or shows other signs of exercise intolerance or if signs of cardiovascular disease are noted during the exercise test, it will be terminated and the participant will be referred to their personal physician for further evaluation (see DMSP). Premenopausal women will be excluded.