Exercise Training in Women With Heart Disease 2

Inclusion Criteria: 1. Women (i.e., female sex assigned at birth) with CHD (e.g., coronary artery bypass grafting surgery \[CABG\], percutaneous coronary intervention \[PCI\], acute myocardial infarction \[MI\], MI with no obstructive coronary artery disease \[MINOCA\], or ischemia with no obstructive coronary artery disease \[INOCA\] at least 4 weeks post procedure or event; based on clinical evidence this is a safe period of time to exercise); 2. Patient is able to perform a symptom limited CPET (this is the primary outcome and needed to determine peak HR for the exercise training prescription); and 3. Patient is able to read and understand English or French. Exclusion Criteria: 1. Patient is currently participating in routine exercise training (\>2x/week, routine exercise training is defined as a planned, structured, and repetitive exercise that is performed in order to maintain or improve physical fitness.) (this may reduce the impact of HIIT or MICT on outcomes); 2. Patient has: NYHA class III-IV heart failure symptoms; unstable angina; or established diagnosis of chronic obstructive pulmonary disease, severe mitral or aortic stenosis, or hypertrophic obstructive cardiomyopathy (this may interfere with the ability to engage in MICT or HIIT); 3. Patient has uncontrolled arrhythmia (this may impact the HR-based exercise training prescription and monitoring); 4. Patient is unable to provide written informed consent; or 5. Patient is unwilling or unable to return for follow-up visits at 12 and 26 weeks. 6. Patient is unwilling to be randomized to HIIT or MICT.