title: Beyond recreational physical activity: examining occupational and household activity, transportation activity, and sedentary behavior in relation to postmenopausal breast cancer risk.
abstract: OBJECTIVE
  We prospectively examined nonrecreational physical activity and sedentary behavior in relation to breast cancer risk among 97 039 postmenopausal women in the National Institutes of Health-AARP Diet and Health Study.
  
  
  METHODS
  We identified 2866 invasive and 570 in situ breast cancer cases recorded between 1996 and 2003 and used Cox proportional hazards regression to estimate multivariate relative risks (RRs) and 95% confidence intervals (CIs).
  
  
  RESULTS
  Routine activity during the day at work or at home that included heavy lifting or carrying versus mostly sitting was associated with reduced risk of invasive breast cancer (RR = 0.62; 95% CI = 0.42, 0.91; P(trend) = .024).
  
  
  CONCLUSIONS
  Routine activity during the day at work or home may be related to reduced invasive breast cancer risk. Domains outside of recreation time may be attractive targets for increasing physical activity and reducing sedentary behavior among postmenopausal women.
authors.affiliation: Nutritional Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, Rockville, MD, USA. materess@mail.nih.gov
authors.forename: Stephanie M
authors.initials: SM
authors.lastname: George
authors.forename: Melinda L
authors.initials: ML
authors.lastname: Irwin
authors.forename: Charles E
authors.initials: CE
authors.lastname: Matthews
authors.forename: Susan T
authors.initials: ST
authors.lastname: Mayne
authors.forename: Mitchell H
authors.initials: MH
authors.lastname: Gail
authors.forename: Steven C
authors.initials: SC
authors.lastname: Moore
authors.forename: Demetrius
authors.initials: D
authors.lastname: Albanes
authors.forename: Rachel
authors.initials: R
authors.lastname: Ballard-Barbash
authors.forename: Albert R
authors.initials: AR
authors.lastname: Hollenbeck
authors.forename: Arthur
authors.initials: A
authors.lastname: Schatzkin
authors.forename: Michael F
authors.initials: MF
authors.lastname: Leitzmann
mesh_terms: D000367:Age Factors; D001943:Breast Neoplasms / Q000453:epidemiology / Q000209:etiology*; D016001:Confidence Intervals; D015444:Exercise; D005191:Family Characteristics; D005260:Female; D006801:Humans; D008875:Middle Aged; D009043:Motor Activity; D017698:Postmenopause; D016016:Proportional Hazards Models; D011998:Recreation; D012306:Risk; D012307:Risk Factors; D057185:Sedentary Behavior; D013997:Time Factors; D014186:Transportation / Q000706:statistics & numerical data; D014481:United States / Q000453:epidemiology; D017132:Workplace / Q000706:statistics & numerical data