Effects of two types of aerobic exercises on low density lipoprotein (LDL) oxidation and cardiovascular risk factors in non-active men

As suggested by some studies lipids oxidation, especially low-density lipoprotein (LDL) - not its mere concentration- is the main cause of atherosclerosis processes. Besides, it has been reported that exercise and physical activity influences LDL oxidation process and its qualitative characteristics. The present study was carried out to determine the effects of two types of aerobic exercises (moderate and vigorous) on LDL oxidation and other cardiovascular risk factors. This semi-experimental study was performed on 44 non-active men. These subjects were divided into a case and a control group. The case (training group) carried out the designed trainings for 8 weeks, 3 sessions per week and each session 30-45 minutes while the control group did not have any regular activity at the same time. Moderate and vigorous aerobic exercises were performed at 60-65% and 80-85% of maximal cardiac reserve rate respectively. Dependent variables (oxidized LDL, HDL, LDL, total cholesterol, triglyceride, body mass index) were measured in the three phases of the study, including pre-test, mid-test, and post-test. To show the effect of exercise, ANOVA statistical test was used and P<0.05 was taken as the significant level. Serum oxidation of LDL, LDL concentration, total cholesterol (TC) or triglyceride (TG) concentration did not reveal any significant differences among the three groups of participants. However, it was observed that HDL concentration and serum HDL/LDL ratio significantly increased and body mass index (BMI) significantly decreased (P<0.05) in vigorous aerobic exercise group after 8 weeks. The findings of this study suggest that performing aerobic exercises (up to 60-85 percent of maximal cardiac reserve rate) could not produce high oxidative stress and due to lack of LDL oxidation condition a significant change in the defensive factors, which are usually utilized against acute atherogenic conditions, does not occur.