BACKGROUND. Official guidelines from the
Centers for Disease Control and Prevention assert that the majority of health benefits from
physical activity are obtained by walking 2 miles (3.2
km) briskly most days of the week (the energy equivalent of
running 8 to 12
km per week). The objective of our study was to examine the dose-response relation in women between
risk factors for
coronary heart disease, particularly the
concentration of
high-density lipoprotein (HDL) cholesterol, and vigorous
exercise at levels that exceed the official guidelines. METHODS. The number of kilometers run per week reported by 1837 female recreational runners in a national
cross-sectional survey was compared with medical data provided by the women's physicians. RESULTS. In these
cross-sectional data,
plasma HDL cholesterol concentrations were higher by an average (+/-
SE) of 0.133 +/- 0.020
mg per deciliter (0.003 +/- 0.0005
mmol per liter) for every additional kilometer run per week, an amount nearly identical with that previously reported for men (0.136 +/- 0.006
mg per deciliter [0.004 +/- 0.0002
mmol per liter] per kilometer per week). Among women who ran less than 48
km per week,
mean plasma HDL concentrations were significantly higher with each 16-
km increment in distance. Women who ran more than 64
km per week had significantly higher
mean concentrations of
HDL cholesterol than did women who ran less than 48
km per week. They were also significantly more likely to have
HDL cholesterol concentrations greater than 100, 90, or 80
mg per deciliter (2.6, 2.3, or 2.1
mmol per liter) than were women
running less than 64
km per week.
HDL cholesterol concentrations increased significantly in relation to the number of kilometers run per week in
premenopausal women who were not using
oral contraceptives and in
postmenopausal women, whether they were receiving
estrogen-replacement therapy or not. CONCLUSIONS. Substantial increases in
HDL cholesterol concentrations were found in women who exercised at levels exceeding current guidelines; higher
HDL cholesterol concentrations could provide added health benefits to these women.