Purpose: Middle-aged and older women who are physically active have decreased risk of coronary heart disease (CHD); however, little is known about how physical activity during young adulthood influences activity during middle age and older, and CHD risk. We examined the relationship between 1) physical activity during young adulthood and middle age, and 2) physical activity during each time period and CHD occurring in middle age or older.
Methods: Cohort study of 39,876 healthy U.S. female health professionals, age > or = 45 yr, in the Women's Health Study. Physical activity was reported at baseline. Additionally, physical activity in high school and age 18-22 yr was reported on the 24-month follow-up survey. Women were followed for an average of 9 yr, after the 24-month survey, for CHD occurrence (N = 477).
Results: Among 37,169 eligible participants at baseline, the most active women (vigorous physical activity 10-12 months x yr) during high school and age 18-22 yr were more than twice as likely to meet physical activity recommendations at baseline than the least active women (no vigorous activity) during high school and age 18-22 yr (multivariate-adjusted odds ratio = 2.43; 95% C.I. 2.24, 2.63). At baseline, the most active women (> or = 1500 kcal x wk(-1)) had a 39% lower risk of CHD during follow-up than the least active (<200 kcal x wk(-1)) (multivariate-adjusted relative risk = 0.61; 95% C.I. 0.46, 0.81). However, physical activity during young adulthood was not associated with risk of CHD occurring during middle age and older.
Conclusion: Women who are physically active during young adulthood are more likely to be active when middle-aged and older, when rates of CHD increase, and physical activity during middle-age predicts lower risk of CHD.