As Dr. Amit Khera, the director of the Southwestern Medical Center’s Program in Preventive Cardiology at the University of Texas said on the issue, “Lots of people, even lots of doctors, assume that exercise lowers cholesterol, but until recently, most of us weren’t sure just what the connection was”1.
Today we have more information on how exercise benefits cholesterol levels, First, it’s important to understand how cholesterol works in the body.
How Does Cholesterol Work?
Most of the cholesterol in our bodies is made by the liver. It’s a fatty steroid molecule used to strengthen cell membranes. It also composes bile salts to help digest fat. However, a cholesterol molecule cannot travel through the bloodstream by itself; it needs to be carried.
Cholesterol is moved through the body by combining with lipoproteins to handle different bodily functions. In regards to your cholesterol levels, two types are the most important: low-density lipoproteins (LDL) and high-density lipoproteins (HDL).
LDLs move cholesterol from the liver to cells; HDLs move cholesterol from cells to the liver. LDLs are often referred to as “bad” cholesterol because as one ages, LDLs can deposit excess cholesterol to arterial walls even when it isn’t needed. HDL is considered “good” cholesterol. HDLs help to scrub arterial walls of excess cholesterol and move it to the liver where it’s processed and flushed out of the body.
The higher your LDL levels, the more cholesterol collects in your arteries, constricting blood flow and increasing blood pressure. This can lead to heart attacks and/or strokes. It’s important to note that “good” and “bad” cholesterol are relative terms, as all types are needed for healthy cholesterol levels.
How Exercise Works to Lower Cholesterol
Fat-burning exercise helps lower LDL production at the same time as it increases HDL levels. Exercise has also been found to increase production of the lipoprotein lipase enzymes. These enzymes do double duty of helping HDLs move cholesterol to the liver so it can be processed and moved out of the body. They also aid in the breakdown of excess fatty LDLs.
Exercise also helps to increase the size of the cholesterol molecule. While it might seem larger/spongier molecules would clog arteries faster, this not the case. When cholesterol is moved to the cells via LDLs, larger cholesterol molecules are less likely to get lodged in the heart’s cellular wall and cause problems.
In fact, a study published in the New England Journal of Medicine2 showed that the amount of exercise has a big effect on the size of cholesterol molecules. The more exercise a person does the lower their cholesterol will be.
Lack of exercise is one of the biggest contributors to unhealthy cholesterol levels as well as general health decline. “We were actually surprised that the individuals who did not exercise deteriorated as rapidly as they did in measurements of blood cholesterol, weight gain and overall health,” stated William E. Kraus, M.D., the Duke University Medical Center research who led the study. “This is characteristic of what is happening to the American population. So if we can get these people exercising, perhaps we can prevent bad things from happening”3.
Amount of Exercise Needed
Research is ongoing but doctors agree that 30 minutes a day of moderate exercise is the target amount to maintain healthy cholesterol levels. This can be walking, biking, swimming or light/moderate aerobic exercise like yoga, tennis or golf. This effect seems to produce better results in men than in women because the male hormone testosterone aids HDLs in cholesterol transport. Exercise helps men maintain higher testosterone levels as they age.
How much exercise is needed to lower your individual cholesterol levels depends on your age, sex, weight and other factors. There’s no one-size-fits-all amount that works the same for everyone, but a good goal to work toward is two and half hours (150 minutes) over a five to seven day period. The more you can fit in, the better you should feel, and the more likely you’ll be to see your cholesterol numbers normalize.
However, before starting an exercise program, talk to your doctor. He or she can help you determine a regimen that’s right for your particular health needs.
2Kraus WE, Houmard JA, Duscha BD, et al. Effects of the amount and intensity of exercise on plasma lipoproteins. N Engl J Med. 2002;347(19):1483-92.
3Mock, Geoffrey. Exercise Show to Have Positive Effect on Cholesterol. DukeToday. http://today.duke.edu/2002/11/exercise1102.html. Accessed March 10, 2015.