Highlights In the physical rehabilitation of patients after coronary artery bypass surgery (CABG), special attention has recently been paid to respiratory rehabilitation. The article presents the results of studies demonstrating that a course of respiratory coordination training was associated with a decrease in the incidence of hydrothorax, improved blood oxygen saturation, increased exercise tolerance and muscle strength by reducing diaphragm dysfunction and increasing respiratory muscle strength in patients in the postoperative period. AbstractAim. To analyze the clinical effectiveness of a new method of breathing exercises developed for improving breathing control in complex early rehabilitation of patients who underwent CABG.Methods. The study involved 73 patients with coronary artery disease (CAD) who underwent CABG at the Federal State Budgetary Institution “Research Institute for Complex Issues of Cardiovascular Diseases” (Kemerovo, Russia) in 2021. During the inpatient rehabilitation, patients were randomized into two groups comparable in anamnestic and baseline clinical and functional indicators: the experimental group (38 patients) had individual breathing exercises as a part of respiratory gymnastics (with different types of exercises), and the control group (35 patients) underwent conventional exercise training.Results. Initially, there were no statistically significant differences between the groups. After 14 days the number of patients in the main group with signs of hydrothorax was significantly lower compared with the control group: 7 (18.4%) vs 11 (31.4%), respectively, p = 0.001. The ultrasound examination of the pleural space revealed the same pattern - hydrothorax was less pronounced in the main group compared with the control group: 0.9 [0.5; 1.5] vs 1.7 [0.6; 2.5] mL, p = 0.049. Analysis of oxygen saturation (SpO₂,%), reflecting the functional status of the oxygen transport system, showed higher blood oxygen saturation rates in the main group compared with the control group: 98 [96; 99] vs 95.2[94; 97]%, p = 0.04, respectively. At the same time, the exercise tolerance (ET) estimated with bicycle ergometry was comparable at baseline in both groups, and at the end of the inpatient rehabilitation ET in the main group was significantly higher than in the control group with conventional exercise training: 74. 9 [50; 100] vs 55.1[25; 75] W, p = 0.005, respectively.Conclusion. Respiratory gymnastics facilitates cardiac and respiratory rehabilitation mainly by improving the coordination of respiratory muscles and preparing them for respiratory gymnastics within short period of early inpatient rehabilitation.