Short-term inspiratory muscle training potentiates the benefits of aerobic and resistance training in patients undergoing CABG in phase II cardiac rehabilitation program

OBJECTIVE To investigate the efficiency of short-term inspiratory muscle training program associated with combined aerobic and resistance exercise on respiratory muscle strength, functional capacity and quality of life in patients who underwent coronary artery bypass and are in the phase II cardiac rehabilitation program. METHODS A prospective, quasi-experimental study with 24 patients who underwent coronary artery bypass and were randomly assigned to two groups in the Phase II cardiac rehabilitation program: inspiratory muscle training program associated with combined training (aerobic and resistance) group (GCR + IMT, n=12) and combined training with respiratory exercises group (GCR, n=12), over a period of 12 weeks, with two sessions per week. Before and after intervention, the following measurements were obtained: maximal inspiratory and expiratory pressures (PImax and PEmax), peak oxygen consumption (peak VO2) and quality of life scores. Data were compared between pre- and post-intervention at baseline and the variation between the pre- and post-phase II cardiac rehabilitation program using the Student's t-test, except the categorical variables, which were compared using the Chi-square test. Values of P<0.05 were considered statistically significant. RESULTS Compared to GCR, the GCR + IMT group showed larger increments in PImax (P<0.001), PEmax (P<0.001), peak VO2 (P<0.001) and quality of life scores (P<0.001). CONCLUSION The present study demonstrated that the addition of inspiratory muscle training, even when applied for a short period, may potentiate the effects of combined aerobic and resistance training, becoming a simple and inexpensive strategy for patients who underwent coronary artery bypass and are in phase II cardiac rehabilitation.