title: Frequency, Type, and Volume of Leisure-Time Physical Activity and Risk of Coronary Heart Disease in Young Women.
abstract: The inverse association between physical activity and coronary heart disease (CHD) risk has primarily been shown in studies of middle-aged and older adults. Evidence for the benefits of frequency, type, and volume of leisure-time physical activity in young women is limited.
  
  
  
  We conducted a prospective analysis among 97 230 women aged 27 to 44 years at baseline in 1991. Leisure-time physical activity was assessed biennially by questionnaire. Cox proportional hazards models were used to examine the associations between physical activity frequency, type, and volume, and CHD risk.
  
  
  
  During 20 years of follow-up, we documented 544 incident CHD cases. In multivariable-adjusted models, the hazard ratio (95% confidence interval) of CHD comparing ≥30 with <1 metabolic equivalent of task-hours/wk of physical activity was 0.75 (0.57-0.99) (P, trend=0.01). Brisk walking alone was also associated with significantly lower CHD risk. Physical activity frequency was not associated with CHD risk when models also included overall activity volume. Finally, the association was not modified by body mass index (kg/m(2)) (P, interaction=0.70). Active women (≥30 metabolic equivalent of task-hours/wk) with body mass index<25 kg/m(2) had 0.52 (95% confidence interval, 0.35-0.78) times the rate of CHD in comparison with women who were obese (body mass index≥30 kg/m(2)) and inactive (physical activity <1 metabolic equivalent of task-hours/wk).
  
  
  
  These prospective data suggest that total volume of leisure-time physical activity is associated with lower risk of incident CHD among young women. In addition, this association was not modified by weight, emphasizing that it is important for normal weight, overweight, and obese women to be physically active.
authors.affiliation: From the Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington (A.K.C., B.H.); Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (A.H.E., E.B.R.); Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.H.E., E.B.R.); Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA (K.J.M.); and Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA (E.B.R.). achomist@indiana.edu.
authors.forename: Andrea K
authors.initials: AK
authors.lastname: Chomistek
authors.affiliation: From the Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington (A.K.C., B.H.); Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (A.H.E., E.B.R.); Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.H.E., E.B.R.); Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA (K.J.M.); and Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA (E.B.R.).
authors.forename: Beate
authors.initials: B
authors.lastname: Henschel
authors.affiliation: From the Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington (A.K.C., B.H.); Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (A.H.E., E.B.R.); Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.H.E., E.B.R.); Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA (K.J.M.); and Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA (E.B.R.).
authors.forename: A Heather
authors.initials: AH
authors.lastname: Eliassen
authors.affiliation: From the Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington (A.K.C., B.H.); Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (A.H.E., E.B.R.); Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.H.E., E.B.R.); Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA (K.J.M.); and Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA (E.B.R.).
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Mukamal
authors.affiliation: From the Department of Epidemiology and Biostatistics, School of Public Health, Indiana University, Bloomington (A.K.C., B.H.); Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA (A.H.E., E.B.R.); Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA (A.H.E., E.B.R.); Department of Medicine, Beth Israel Deaconess Medical Center, Boston, MA (K.J.M.); and Department of Nutrition, Harvard T.H. Chan School of Public Health, Boston, MA (E.B.R.).
authors.forename: Eric B
authors.initials: EB
authors.lastname: Rimm
mesh_terms: D000328:Adult; D003327:Coronary Disease / Q000453:epidemiology*; D015444:Exercise; D005247:Feeding Behavior; D005260:Female; D006801:Humans; D006937:Hypercholesterolemia / Q000453:epidemiology; D006973:Hypertension / Q000453:epidemiology; D007899:Leisure Activities; D008137:Longitudinal Studies; D008593:Menopause; D008875:Middle Aged; D009726:Nurses; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk; D012907:Smoking / Q000453:epidemiology; D013177:Sports; D011795:Surveys and Questionnaires; D013690:Television
keywords: epidemiology; exercise; myocardial infarction; women