Table 1.

Vigorous exercise at baseline according to baseline characteristics (age-standardized)

H/wk
Characteristics<11–4≥5
Number of women22,76014,6385,399
Age, %
 30–39375154
 40–49373433
 50–59181210
 ≥60833
BMI, mean29.427.626.7
≥16 years of education, %405148
Age at menarche ≤ 11, %282726
Nulliparous, %242930
First birth before age 20, %272225
Recent oral contraceptive user, %323333
Female hormone user, %192019
Premenopausal, %707171
Age at menopause < 45, %212020
Family history of breast cancer, %778
Cigarette smoking, %
 Never smoked586058
 <20 pack years303131
 ≥20 pack years1088
Alcohol consumption, %
 Never drank585655
 <7 drinks/d353736
 ≥7 drinks/d668
Vegetable/fruit pattern, top quintile, %152533
Meat/fried foods pattern, top quintile, %231613
Any walking for exercise at baseline
 <1 h/wk572720
 ≥5 h/wk81341
Brisk walking for exercise at baseline
 <1 h/wk877164
 ≥5 h/wk3619
Vigorous exercise at age 30
 ≥5 h/wk91960
Vigorous exercise at age 21
 ≥5 h/wk183253
Vigorous exercise in high school
 ≥5 h/wk284562
Sitting watching TV at baseline
 <1 h/d101313
 ≥5 h/d171115
Sitting at work at baseline
 <1 h/d201618
 ≥5 h/d485050