Postoperative pulmonary complications (PPCs) after coronary artery bypass graft (CABG) surgery are a major source of morbidity and mortality, and increase length of hospital stay and resource utilization. The prehospitalization period before CABG surgery may be used to improve a patient's pulmonary condition. The efficacy of preoperative inspiratory muscle training (IMT) in reducing the incidence of PPCs in high-risk patients undergoing CABG surgery has not yet been determined.