Common knowledge is that exercise helps lower cholesterol. You might think this means any kind of exercise at any intensity and for any duration. However, you would be wrong. Low density lipoprotein cholesterol is affected by the intensity at which you exercise. High intensity exercise may actually increase levels of blood LDL.
LDL Cholesterol
LDL cholesterol is also known as the "bad" cholesterol. It gets this reputation because it is the transporter responsible for delivering cholesterol to various parts of the body. It also contributes to atherosclerosis. When plaque begins to build up on the walls of your arteries, it is LDL cholesterol that gets oxidized and causes the blockage to worsen.
LDL Normal Levels
There are four classifications of LDL levels. A reading of less than 100 mg/dL is considered healthy. If your LDL falls between 100 to 129 mg/dL, you are above the ideal level. You are considered borderline high if your LDL is 130 to 159 mg/dL. An LDL content of 160 to 189 mg/dL is high and a reading above 190 mg/dL is very high. These categories can also give you an idea of your risk for developing cardiovascular disease, as an elevated cholesterol profile is a risk factor for heart disease.
Exercise and LDL
High intensity, strenous activity can contribute to increased LDL in your blood. A study published in the journal "Atherosclerosis" in 1995 by Jorge Sachez-Quesada and colleagues evaluated the effects of strenous exercise on LDL levels. Six runners fasted, then ran for four hours after which LDL cholesterol levels were monitored. Immediately after and up to two hours post-run, levels of oxidized LDL had increased in all runners.
Exercise Prescription
If you are exercising to decrease levels of LDL cholesterol, you should aim for endurance type activity. This is moderate intensity activity that is done for a prolonged period of time. This kind of exercise helps to increase LDL receptor sensitivity which in turn decreases amounts of LDL inside of the bloodstream.
References
- "Exercise Physiology"; George A. Brooks, Thomas D. Fahey, Kenneth M. Baldwin; 2005
- "Exercise Testing and Prescription"; David C. Nieman; 2007
- National Heart Lung and Blood Institute: High Blood Cholesterol
- Atherosclerosis Journal: Increase of LDL Susceptibility to Oxidation Occuring After Intense, Long Duration Aerobic Exercise
