Abstract Purpose To evaluate the clinical effects of high-intensity physical exercise prehabilitation for elective coronary artery bypass grafting on the optimization of the postoperative course in patients with stable coronary artery disease. Methods 60 male patients with stable coronary artery disease (CAD) were randomized into two groups before elective on-pump CABG. Group 1 patients (n=30, aged of 61.5 [56; 63] years) underwent a 7-day course of treadmill training at 80% of VO2 max. Group 2 patients (n=30, aged of 62.0 [56; 64] years) underwent routine preoperative management. The length of stay in the ICU and the length of stay in the hospital were assessed in all patients. In addition, the postoperative rate of myocardial infarction, stroke, heart rhythm disturbances (including atrial fibrillation), heart failure requiring inotropic support, hydrothorax and hydropericardium requiring puncture, wound infections, sternum diastasis, MODS, and the composite endpoint (total number of complications) were assessed. Statistical analysis was performed using the commercially available software package Statistica 10.0 (Statsoft, USA). Results Both groups were comparable in the main clinical and demographic data, and the intraoperative parameters. There were no cases of complications, heart and coronary insufficiency, episodes of heart rhythm disturbance and conduction disorders in patients undergoing preoperative physical training. All patients had good exercise tolerance. The trend towards reduced length of stay in the ICU and the length of stay in the hospital had been found in patients who underwent exercise prehabilitation compared with patients without training (20.0 [19.0; 22.0] vs. 21.0 [20.0; 23, 0] hours, respectively, p>0.05 and 11.0 [9.5; 12.0] vs. 12.0 [10.0; 12.0] days, respectively; p>0.05). There were no cases of intraoperative MI and postoperative stroke in Group 1 patients, whereas one case of MI and one case of stroke were registered in Group 2. The rate of the composite endpoint was lower in Group 1 patients than in Group 2 patients (p=0.02). In addition, the incidence of AF (6.6 and 10%, respectively), heart failure (6.6 and 20%, respectively), hydrothorax (0 and 6.6%, respectively) and pneumonia (0 and 6, 6%, respectively) was lower in Group 1 patients than in Group 2 patients. Conclusion The positive effects of high-intensity physical exercise prehabilitation for CABG on the optimization of postoperative course has been confirmed. Funding Acknowledgement Type of funding source: None