Exercise increases levels of beneficial HDL cholesterol and reduces the risk of heart disease and stroke. Exercise Science at the University of New Mexico reports exercise increases serum HDL in women, but other factors such as hormonal status, exercise type and intensity may play significant roles.
Definition
Low density lipoprotein, or LDL, also known as bad cholesterol, transports cholesterol to the arteries and various body cells. Excess cholesterol that gets deposited onto artery walls increases the risk of heart disease and stroke. High density lipoprotein, or HDL, also known as good cholesterol, transports cholesterol from the blood and arteries to the liver, where it is expelled from the body or converted into bile. Bile is used to digest fat.
Moderate Exercise
Regular moderate exercise such as walking may increase serum HDL cholesterol levels in women. In a study published in the December 1991 issue of the "Journal of the American Medical Association," researchers from the Coopers Institute for Aerobic Research Dallas, concluded exercise intensity, however, was not significant. The women in the study constituted three groups who walked 2.98 miles a day for 14 weeks at varying speeds or levels of intensity. Increases in HDL were similar in those who walked at intensity sufficient to improve cardiovascular fitness and the strollers who showed minimal improvement in cardiovascular fitness.
Resistance Exercise
Premenopausal and postmenopausal women react differently to resistance training. The level of intensity and duration of the program may also be a factor. Regular resistance training reduces total cholesterol levels and decreases the ratio of LDL to HDL in premenopausal women according to a study reported in the June 1999 issue of the "British Journal of Sports Medicine." The women in the study embarked on an intense three days a week, 14-week resistance training program. However, there was no reported increase in serum HDL levels. Researchers at the John Moores University Liverpool reported in a study published in the February 2002 issue of the "British Journal of Sports Medicine" that eight weeks of low intensity resistance training by postmenopausal women produced no significant changes in cholesterol levels or increases in HDL levels.
Contraceptive Effect
The use of hormone based oral contraceptives may affect how women's cholesterol levels responds to regular exercise. In a study reported in the December 1980 issue of "Metabolism," 13 previously sedentary women aged 18 to 30 who were on a specific oral contraceptive underwent a 10-week cardiovascular exercise program consisting of three weekly 30-minute sessions. The exercise program improved aerobic capacity but did not induce an increase in serum HDL cholesterol levels. Men who undergo similar exercise programs show an increase in HDL levels.
Menopause Effect
Exercise can increase serum HDL levels in postmenopausal women according to a study headed by D.R. S.R. Lindheim of the University of Wisconsin School of Medicine and Public Health, published in the February 1994 issue of "Obstetrics and Gynecology." Lindheim's study concluded hormone replacement therapy had the most significant positive impact on the ratio of HDL to LDL in postmenopausal women. However, exercise combined with HRT did not further increase levels of HDL cholesterol.
References
- "Exercise Science at the University of New Mexico"; A Review of the Impact of Exercise on Cholesterol Levels; Chantall Vella
- "Journal of the American Medical Association"; Jonh Duncan Ph.D., et al.; December 1999
- "British Journal of Sports Medicine"; Effect of 14 Weeks of Resistance Training on Lipid Profile and Body Fat Percentage in Premenopausal Women; B. Prabrakahan, et al.; June 1999
- "British Journal of Sports Medicine"; Effects of Resistance Training and Detraining on Muscle Strength and Blood Lipid Profiles in Postmenopausal Women; K.J. Eliott, et al.; October 2002
- "Metabolism"; Effect of a Controlled Exercise Program on Serum Lipoprotein Levels in Women on Oral Contraceptives; T.P. Wynne, et al.; December 1980
- "Obstretics and Gynecology";The Independent Effects of Exercise and Estrogen on Lipids and Lipoproteins in Postmenopausal Women; S.R. Lindheim, et al.; February 1994
