Links have been established between high levels of LDL cholesterol and coronary heart disease. Diet and exercise are the two primary recommendations of ways to lower LDL cholesterol, also known as "bad cholesterol." In some cases of cholesterol testing, individuals who exercised prior to having blood drawn found that their LDL cholesterol levels actually increased. Although exercise improves an overall blood panel, strenuous physical exercise prior to a blood draw may negatively impact the results.
Cholesterol and LDL
While some cholesterol is essential for cell structure and function, excess levels in your bloodstream cause cholesterol buildup in your arteries, increasing your risk of developing heart disease. The two main types of cholesterol are HDL and LDL. HDL cholesterol is "good" cholesterol. It actually picks up fat from the arteries, so you will benefit from having high HDL cholesterol. LDL cholesterol is called "bad" because it deposits excess fat in the artery walls, increasing health risks. Keeping LDL levels low is recommended for overall health.
Exercise and Cholesterol
The relationship between exercise and cholesterol levels may not be easily understood since the volume and intensity of exercise produce different results. Volume of exercise seems to have a greater effect on LDL cholesterol than the intensity of your workout. Sedentary individuals and those with low levels of activity tend to have high LDL levels, but exercising 30 minutes or more on most days of the week lowers LDL. While regular, moderate-intensity exercise in the weeks leading up to a cholesterol test may result in a lower level of LDL cholesterol, a single high-intensity workout immediately before a blood test is not likely to effect a positive change.
Aerobic Exercise Increases LDL
In a study published in "Journal of Atherosclerosis," researchers studied marathon runners after a four-hour, high-intensity run. They performed blood tests before and after exercise and found that the runners had greater levels of LDL in their bloodstream afterwards than before. The high-intensity and long duration of the exercise may change the body's fat metabolism, temporarily increasing LDL levels to provide fat in the bloodstream to be broken down for energy. Because of these results, high-intensity exercise just before a cholesterol test may actually cause a blood panel with temporarily elevated levels of LDL cholesterol.
Resistance Exercise Lowers LDL
Although aerobic exercise remains recommended for lowering LDL cholesterol, research indicates that resistance exercise also effectively lowers LDL levels. A study published in "British Journal of Sports Medicine" looked at the role of resistance exercise and cholesterol levels in two groups of women. After 14 weeks, women who performed 45 minutes of resistance training three days each week significantly reduced LDL cholesterol levels. A similar study published in "Cardiovascular Journal of Africa" compared men after 16 weeks of no exercise, aerobic exercise only or a combination of resistance and aerobic exercise. Both the aerobic and combination group saw similar decreases in LDL cholesterol, indicating that resistance exercise by itself or added to an aerobic workout effectively lowers LDL levels.
- University of New Mexico: The Exercise and Cholesterol Controversy
- University of New Mexico: A Review of the Impact of Exercise on Cholesterol Levels
- Journal of Atherosclerosis: Increase of LDL Susceptibility to Oxidation Occurring After Intense, Long Duration Aerobic Exercise
- The British Journal of Sports Medicine: Effect of 14 Weeks of Resistance Training on Lipid Profile and Body Fat Percentage in Premenopausal Women
- Cardiovascular Journal of Africa: Comparison of Aerobic and Combined Aerobic and Resistance Training on Low-Density Lipoprotein Cholesterol Concentrations in Men