Effects of a low-intensity dynamic-resistance training protocol using an isokinetic dynamometer on muscular strength and aerobic capacity after coronary artery bypass grafting

Abstract

Study the effect of muscle strength training on muscle strength, maximal oxygen uptake (VO2max), hemodynamic and anthropometric parameters as well as quality of life after coronary artery bypass grafting (CABG). After CABG surgery, 32 patients were randomized into two groups. The first group was to perform aerobic-type training with a cycle ergometer (AT=16). The second group was to perform low-intensity muscle strength training of the quadriceps and hamstrings using an isokinetic dynamometer (i.e. 20 to 30% of peak torque) (ST=16). Before and after the strength training program we conducted a stress test, evaluation of isokinetic force production, 6-minute walking test, body impedance analysis (BIA) and SF-36 quality of life test. Compared to the AT group, the ST group showed better results with improved quadriceps strength (48.2% vs. 8.2%), VO2max (P<.001) and diastolic blood pressure at rest (P=0.01). Quality of life improved in both groups. The dynamic-resistance muscle strength training protocol using isokinetic dynamometer can safely (i.e. without clinical symptoms or changes to the ECG and arterial blood pressure) improve muscle strength and VO2max without any major risks in patients post-CABG. These findings should encourage additional studies to validate the relevance of these strength training modalities in rehabilitation centers.