A comparison of the effects of strength and aerobic exercise training on exercise capacity and lipids after coronary artery bypass surgery

Abstract

Coronary artery surgery improves symptoms and prognosis in patients with angina. Aerobic exercise rehabilitation improves exercise capacity and prognosis in cardiac patients. Strength exercise training has not been extensively studied. We studied the effects of 6 months aerobic and strength exercise training after coronary artery surgery in 81 men, mean age 57 years. Treadmill time(s) increased by 130.3 (95% confidence interval 46.4 to 214.2) in the aerobic group; by 83.1 (0.9 to 165.3) in the strength group, and by 34.3 (-1 to 69.6) in the control group (P = 0.04, control versus aerobic) after 3 months; and by 196.4 (112.2 to 280.7) in the aerobic group, by 122.7 (37.7 to 207.6) in the strength group and by 27 (-40.4 to 94.4) in the control group (P = 0.002, control versus aerobic, and P = 0.03 control versus strength) after 6 months. The level of fitness improved more in the strength-trained group, and there was a minor reduction in body weight and degree of fatness. There were no changes in lipoprotein levels. Aerobic exercise training causes early and sustained benefit in treadmill exercise capacity, while the effects of strength exercise training are later in onset. Exercise training alone did not influence lipid levels. Cardiac rehabilitation programmes should be comprehensive, including advice on diet and other risk factor modifications in addition to exercise sessions involving aerobic and strength training elements.