High density lipoprotein, or HDL, cholesterol has been named the "good" cholesterol because it appears to reduce the risk of heart disease when your levels are high. The ideal HDL level is 60 mg/dL or higher, and excess weight, smoking and being inactive are all factors that will adversely affect your HDL cholesterol level. The American Heart Association contends that people with low HDL cholesterol usually have high triglyceride levels, which is a risk factor for heart disease. Scientific evidence supports exercise helps people in this category.
Effect of Exercise Depends on Triglyceride Levels
A 20-week study published in the journal "Atherosclerosis, Thrombosis and Vascular Biology" in 2001 had 200 men undergo an endurance training program. The men were grouped in four categories based on HDL cholesterol and triglyceride (TG) levels: Low TG and high HDL; low TG and low HDL; high TG and high HDL; and high TG and low HDL. The researchers found that the men with low HDL who also had low triglyceride levels showed no appreciable change in their HDL levels in response to exercise. Those with high triglyceride levels and low HDL cholesterol levels, however, had a significant increase in HDL levels after exercise intervention.
Exercise May Activate Genetic Components
The journal "Circulation: Cardiovascular Genetics" reported a 2011 study relating the effect of exercise on the HDL levels of subjects with specific genetic variations. From a group of 22,939 healthy female subjects, 58 changes, called single nucleotide polymorphisms, or SNPs, in nine different genes were identified that showed association with HDL cholesterol levels. The researchers wanted to determine whether physical activity would have any effect on these genes and subsequently on HDL levels. They noted that seven SNPs responded to exercise by modifying HDL cholesterol levels, although the increase was more pronounced in some than in others.
How Exercise Changes HDL
The increase in HDL concentration in response to exercise may be partly due to an increase in the expression of the enzyme lipoprotein lipase, or LPL, an enzyme used in triglyceride metabolism. Exercise increases LPL activity, which, in turn, increases HDL cholesterol concentration. Exercise may also slow the breakdown of HDL cholesterol, which will improve your HDL cholesterol level.
Considerations
A 2001 editorial in the journal "Atherosclerosis, Thrombosis and Vascular Biology" suggests that exercise may have a number of physiological methods of causing changes in HDL cholesterol levels, ways that are influenced by factors as diverse as amount of body fat, insulin resistance and triglyceride levels. With so many variables, the improvement in your HDL cholesterol level after you begin an exercise regime may be significant, or the change may be negligible. The overall benefits of exercise should prompt you to keep being active, however, regardless of the effect on your HDL cholesterol.
References
- American Heart Association: What Your Cholesterol Levels Mean
- "Atherosclerosis, Thrombosis and Vascular Biology": Exercise and HDL Levels; C. Couillard, et al.; July 2001
- Circulation: Cardiovascular Genetics"; Physical Activity Modifies HDL Level; T. Ahmad, et al.; February 2011
- "Atherosclerosis, Thrombosis and Vascular Biology"; Editorial; Paul Thompson and Daniel Rader; 2001
