Coronary revascularization, such as heart bypass surgery (CABG) and percutaneous coronary intervention (PCI \[inserting a stent to open up blood vessels\]) improve survival for people with coronary artery disease. Yet, many patients suffer from poor physical and mental health after coronary revascularization. Traditional cardiac rehabilitation involving moderate-to-vigorous intensity continuous training (MICT) improves physical and mental health. However, alternative exercise programs, such as high-intensity interval training (HIIT) and Nordic walking may provide superior benefits. Nordic walking is like Nordic skiing but uses specifically designed poles for walking. Nordic walking involved core, upper and lower body muscles, resulting in greater energy expenditure while reducing loading stress at the knee. To date, HIIT used in cardiac rehabilitation settings has focused on lower body (e.g., leg cycling). The investigators are not aware of HIIT protocols that target both upper and lower body at the same time. An exercise program that combines HIIT and Nordic walking (HIIT-NoW) may offer an alternative time-efficient whole-body exercise to improve physical and mental health. This study will test if HIIT-NoW can be an alternative exercise option to improve physical and mental health in patients with coronary artery disease.