Acute prolonged exercise reduces moderately oxidized LDL in healthy men

We studied the effects of a 2-day walk exercise (6 h+6 h) on the serum concentration of circulating moderately oxidized LDL (LDL baseline conjugated dienes), lipids (total cholesterol, LDL cholesterol, HDL cholesterol, and triglyceride), antioxidants (alpha-tocopherol, gamma-tocopherol, beta-carotene, and ubiquinol-10), and antioxidant potential in serum (S-TRAP) and LDL (LDL-TRAP) in healthy well-trained men. The exercise was performed twice with an interval of 14 days. While 6 h walking the subjects drank 6 cl . kg (-1) water which contained either carbohydrate (CHO trial) or placebo (PLA trial). During the 2-day exercise the level of oxidized LDL decreased by 25 % (p=0.001) in the PLA trial. At the same time serum gamma-tocopherol decreased by 20 % (p=0.049), while the other measured antioxidants remained unchanged and the serum antioxidant potential increased by 22 % (p=0.018). Serum total cholesterol decreased by 3 % (p=0.017), serum triglycerides by 22 % (p=0.001), and LDL-cholesterol by 14 % (p=0.045). HDL cholesterol increased by 9 % (p=0.001). The results in the carbohydrate trial were similar to the ones in the PLA trial. The findings suggest that exercise of long duration but of low, non-exhaustive intensity decreases the concentration of circulating oxidized LDL simultaneously with an increase in serum antioxidant potential in healthy trained men. Carbohydrate ingestion during the exercise does not have any further effect on these changes.