REDUCED OXIDIZED LDL LEVELS AFTER A 10-MONTH EXERCISE PROGRAM

Purpose: We studied the effect of a 10-month exercise program on LDL o xidation and other lipid risk factors in 34 sedentary men and 70 women . We hypothesized that decreasing LDL oxidation by raising exercise ac tivity would decrease the risk of atherosclerosis. Methods: The men an d women subjects had a mean (range) age of 43.6 (34-52) and 44.6 (31-5 8) 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 base line levels of conjugated dienes extracted from LDL (LDL-BDC) to asses s the amount of circulating LDL oxidation products. The antioxidant po tential of LDL samples was estimated in vitro by their potency to resi st 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) ove r dot O-2max increased by 19% during the exercise program in both men and women (both P < 0.0001). Concurrently, the concentration of HDL ch olesterol 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 trigly ceride concentrations remained unchanged. The concentrations of LDL-BD C 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 wome n. The ratio of LDL antioxidant potential to LDL rose by 16% (P = 0.01 1) 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 < 0.00 01), 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 th e quality of the circulating LDL (less oxidized LDL), which may reduce the risk of atherosclerosis.