Clinical benefits of additional resistance-type exercises during endurance-based exercise intervention in coronary artery disease patients.

Abstract

Purpose: In the early rehabilitation of coronary artery disease (CAD) patients, resistance-type exercises are advocated in addition to endurance-type exercises. However, the clinical effects of these additional exercises remain to be explored. Methods: 55 CAD patients were included and randomly assigned to 6 weeks of endurance exercise training or combined endurance and resistance exercise training (mean 18 sessions). All subjects performed 3 exercises sessions/week at 65% of baseline VO2max, for 40 min/session. In the combined group, leg extension and leg squat exercise were additionally executed: 2 series, 12 up to 25 repetitions. Following parameters were evaluated: maximal exercise capacity and ventilatory threshold (ergospirometry test), body composition (dual x-ray absorptiometry scan), hematology, blood lipid profile and glycemic control, blood endothelial progenitor cell content, muscle strength (dynamometry test on Biodex), home-based habitual activity. Results: 42 CAD patients completed this intervention. In the combined-trained group upper leg lean tissue mass increased significantly (from 20.7±3.2 to 21.1±3.4kg, p<0.05), but not in the endurance-trained group (from 20.4±3.2 to 20.4±3.3kg, p>0.05). The significant improvement in blood haemoglobin content, hematocrit, VO2max, ventilatory threshold, and muscle isokinetic and endurance strength was similar between groups. The significant reduction in adipose tissue was equal between groups. In the combined-trained group, blood HDL cholesterol content increased significantly (from 40±10 to 45±10mg/dl, p<0.05), and white blood cell count decreased significantly (from 6.6±1.5 to 6.0±1.4*10(9), p<0.05), but not in the endurance-trained group (from 40±6 to 41±7mg/dl, and from 6.6±1.1 to 6.4±0.9*10(9), p>0.05). Conclusion: The addition of resistance-type exercises during an endurance exercise intervention in CAD results into a greater increase in blood HDL cholesterol content and decrease in white blood cell count. Therefore, cardiovascular disease risk could be reduced by greater magnitude in CAD patients when adding resistance-type exercises towards endurance-exercise intervention by a novel physiological mechanism.