Cardiac rehabilitation, including physical training, has become accepted treatment following myocardial infarction, coronary stent implantation and coronary bypass operation. Besides modifying patients' risk profile for future coronary problems, the focus is on improving exercise capacity. The ability to be able to perform at a higher maximal level is a strong predictor for outcome (new cardiovascular events and mortality). The main purpose of this study is to evaluate whether aerobic interval training outweighs more classical moderate endurance training in improving exercise capacity. During interval training, patients perform exercise at high intensity, but for only a couple of minutes and then recover at a lower intensity. Such intervals are repeated. Preliminary evidence from smaller studies suggests that this type of training leads to a larger increase in exercise capacity, compared to the more traditional endurance training at moderate intensity.

In addition, mechanisms that might explain how this improvement is achieved, as well as safety and impact on quality of life will be studied.

Inclusion Criteria:

• patients with CAD (post-PCI, post-MI, post-CABG) and a left ventricular ejection fraction (LVEF) > 40%
• the presence of CAD is defined as prior angiographically documented stenotic lesion(s) of > 75%, or documented myocardial infarction (biochemical, ECG, echocardiographic documentation).
• patients are on optimal medical treatment and stable with regard to symptoms and pharmacotherapy for at least 4 weeks
• in practice, patients will have been hospitalized at least 4 weeks prior to participation in the training programme because of PCI, MI or CABG

Exclusion Criteria:

• significant intercurrent illness last 6 weeks
• known severe ventricular arrhythmia with functional or prognostic significance
• significant myocardial ischemia, hemodynamic deterioration or exercise-induced arrhythmia at baseline testing
• recent CABG (< 30 days)
• other heart disease that limits exercise tolerance (valve disease with significant hemodynamic consequences, hypertrophic cardiomyopathy etc.)
• co-morbidity that may significantly influence one-year prognosis
• functional or mental disability that may limit exercise
• a habit of regular vigorous exercise or participation in a programme of exercise training less than 3 months before inclusion
• acute or chronic inflammatory diseases or malignancy, the use of anti-inflammatory drugs or immune suppression
• glomerular filtration rate (GFR) <25ml/min/1.73m2
• hemoglobin < 10g/dl
• severe chronic obstructive pulmonary disease
• participation in another clinical trial