Inclusion Criteria:  Adults with coronary artery disease (CAD) based on an angiogram >50% stenosis in any major epicardial vessel or history of myocardial infarction or history of coronary revascularization. Considered to have stable CAD on optimal medical therapy 60 to 85 years of age Men and women (women must be postmenopausal either natural or surgical) Able to give consent  Exclusion Criteria:  Ejection fraction <50%, unstable angina, recent myocardial infarction within 6 months Coronary revascularization, including percutaneous coronary intervention and coronary artery bypass graft or thoracic surgery within 6 months. Stroke, obstructive pulmonary disease, hepatitis B, C, HIV, seizures, or other relevant on-going or recurrent illness Individuals that have participated in respiratory training within the last 12 months or cardiac rehabilitation within the last 6 months Uncontrolled hypertension Use of tobacco products including smoking traditional or e-cigarettes Use of hormone replacement therapy in women or men (e.g., estrogen, progesterone or testosterone) Regular aerobic exercise training Unwilling to stop using mouthwash at least 1 week before the start of the study and during study participation Unwilling to remain weight stable during study participation