This study examined the effects of different exercise programs on blood lipids and cholesterol levels. 111 sedentary subjects with dyslipidemia were randomly assigned to a control group or one of three exercise groups that varied in intensity (high vs moderate) and amount (high vs low) of weekly exercise. The results showed that exercise significantly reduced small LDL particles and increased average LDL size compared to the control group. The high amount, high intensity group showed the most significant improvement in HDL cholesterol concentration. Overall, the study found that a higher amount of exercise was more beneficial than a lower amount or no exercise for improving lipid profile, though the optimal intensity remains unclear.

1. Exercise as an intervention to reduce blood lipids and cholesterol levelsHarriet Brown, Bond University, Australia

3. Cholesterol is only slightly soluble in water and blood so is transported by lipoproteins VLDL, IDL, HDL and LDL to the tissues. Elevated cholesterol in the blood is detected by abnormalities in lipoprotein levels.

6. Samples: Blood plasma samples were taken after fasting and were analyzied by a nuclear magnetic resonance spectroscopy to measure LDL, HDL, IDL, TC and TGs concentrations including sub-classes. Density-gradient ultracentrifugation was used to separate lipoprotein and cholesterol fractions. Samples were blinded. Data analysis: Analysis of variance using Statview or SAS software, then a post hoc analysis of the data after the experiment concluded was used as the main analysis to compare exercise groups to control.

7. Results Exercise training did not have a significant effect on LDL however, significantly reduced the concentration of small LD particles, increasing the average size of LDL. Figure 1: Comparison of the Effects of Three Different Exercise Programs with Those in a Control Group on Mean Changes in the Concentration of Small Low-Density Lipoprotein (LDL) Cholesterol (Panel A), the Concentration of LDL Particles (Panel B), the Average Size of LDL Particles (Panel C), and the Concentration of Intermediate-Density Lipoprotein (IDL) Cholesterol (Panel D)

10. References 1. Stamlet, J, Wntworth, D, Neaten, J, 1986, Is Relationship Between Serum Cholesterol and Risk of Premature Death From Coronary Heart Disease Continuous and Graded? The Journal of American Medical Association, vol.256, No.20, pp.2823-2828 2. Fuster V, Gotto A, Libby P, Loscalzo J, McGill HC. Pathogenesis of coronary disease: the biological role of risk factors. J Am CollCardiol. 1996;27:964-976 3. Tambalis K, Panagiotakos, D, Kavouras, S, & Sidossis, L 2009, Responses of Blood Lipids to Aerobic, Resistance, and Combined Aerobic With Resistance Exercise Training: A Systematic Review of Current Evidence, Angiology 4. Superko, R, Is Relationship Between Serum Cholesterol and Risk of Premature Death From Coronary Heart Disease Continuous and Graded?, Medecine and science in sport and exercise, Vol.23, No.6 5. Kodama S, Shu M, Saiko K, et al. Even low-intensity and low-volume exercise training may improve insulin resistance in the elderly. Intern Med. 2007;46:1071-1077 6. Durstine L, Grandjean P, Davis P, Ferguson MA, Alderson NL, DuBose KD. Blood lipid and lipoprotein adaptations to exercise. A quantitative analysis. Sports Med. 2001;31:1033-1062 7. Halbert, J, Silagy, C, Finucane, P, Withers, R, & Hamdorf, P, 1999, Exercise training and blood lipids in hyperlipidemic and normolipidemic adults: A meta-analysis of randomized, controlled trials. European Journal of Clinical Nutrition, vol.53, 514-522 Krause et al, 2002, Effects of the Amount and Intensity of Exercise on Plasma Lipoproteins, N Engl J Med 347:1483-1492 American Heart Association. August 2010. [Online] http://www.americanheart.org

11. Any Questions? Thankyou