Reduced oxidized LDL levels after a 10-month exercise program

Purpose: We studied the effect of a 10-month exercise program on LDL oxidation and other lipid risk factors in 34 sedentary men and 70 women. We hypothesized that decreasing LDL oxidation by raising exercise activity would decrease the risk of atherosclerosis. Methods: The men and women subjects had a mean (range) age of 43.6 (34-52) and 44.6 (31-58) yr, a body mass of 94.4 (78-144) and 77.6 (56-117) kg, a body mass index of 29.6 (24-44) and 28.6 (21-41), a body fat percentage of 20.4 (13-29) and 31.4 (16-39), and a maximal oxygen uptake of 33.3 (15-50) and 30.4 (18-49) mL.kg(-1).min(-1), respectively. We measured the baseline levels of conjugated dienes extracted from LDL (LDL-BDC) to assess the amount of circulating LDL oxidation products. The antioxidant potential of LDL samples was estimated in vitro by their potency to resist 2,2'-azobis(2-amidinopropane)HCl-induced peroxidation. The exercise program was tailored individually based on indirect measurement of (V) over dot O-2max at baseline. Results: The mean time of exercise was 257 min.wk(-1) for men and 209 min.wk(-1) for women. Estimated (V) over dot O-2max increased by 19% during the exercise program in both men and women (both P < 0.0001). Concurrently, the concentration of HDL cholesterol increased by 15% in men (P = 0.0004) and 5% in women (P = 0.043) and that of LDL cholesterol decreased by 10% (P = 0.026) and 11% (P < 0.0001), respectively, whereas serum total cholesterol and triglyceride concentrations remained unchanged. The concentrations of LDL-BDC decreased by 23% (P = 0.0010) and 26% (P < 0.0001) and the ratio of LDL-BDC to LDL by 14% (P = 0.016) and 18% (P < 0.0001) in men and women. The ratio of LDL antioxidant potential to LDL rose by 16% (P = 0.011) and 11% (P = 0.0016), respectively. The mean weight loss during the exercise program was 2.9 kg in men and 1.8 kg in women (both P < 0.0001), whereas body fat percentage fell by 2.3% and 3.2%, respectively. Conclusions: In addition to increasing HDL cholesterol and decreasing LDL cholesterol, the exercise program is concluded to have improved the quality of the circulating LDL (less oxidized LDL), which may reduce the risk of atherosclerosis.