Recent (under 3 months) myocardial infarction or suspected myocardial infarction

Unstable coronary heart disease, angina pectoris at rest or during light activities (dressing, eating, washing)

Premature ventricular beats (over 30%)

Uncontrolled atrial arrhythmia influencing cardiac functioning (atrial fibrillation, sustained supraventricular tachycardia)

Third degree atrioventricular block, left bundle branch block (LBBB)

Pacemaker (fixed rhythm)

Recent systemic or pulmonary embolia (under 6 months)

Ventricular aneurysm

Cardiomyopathy

Severe stenosis of aortic valve

Deep vein thrombosis in the extremities or thrombosis in the heart

 Suspected or diagnosed aortic aneurysm

Suspected or active myocarditis or pericarditis

Acute infection

Severe psychological distribution (psychosis, dementia)

Systolic blood pressure at rest over 200 mm Hg, diastolic over 120 mm Hg

Uncontrolled metabolic disease (diabetes, thyreotoxicosis, myxedema etc.)

Anemia (hemoglobin under 100 g·l^-1)

Disorders of neuromuscular system (hemiplegia, osteoarthritis),  which make cycling difficult

The subject refuses to exercise