Table 1 Abnormal health findings considered as the exclusion criteria

1. Pulmonary diseases

- Chronic obstructive pulmonary disease

- poorly controlled bronchial asthma

- blood saturation < 95%

2. Cardiovascular diseases

- significant heart rhythm disturbances in the 12-lead ECG (e.g., ventricular and supraventricular arrhythmias, atrial fibrillation)

- features of myocardial ischemia,

- prolongation of the QT interval in the 12-lead ECG

- structural heart disorders detected in cardiac echocardiography (e.g., hemodynamically relevant valvular defects, hypertrophic cardiomyopathy, systolic dysfunction of the right or left ventricle),

- decompensated blood pressure (with increases above 160/100 mmHg).

3. Neurological and mental disorders

4. Significant deviations found in CBC

- Leukocytosis above 10 000 ∙ mm^− 3

- Anaemia with Hb level < 10 g ∙ d^− 1

5. Exercise-limiting musculoskeletal injuries