title: Physical activity and sedentary behavior in breast cancer survivors: New insight into activity patterns and potential intervention targets.
abstract: BACKGROUND
  Inactivity and sedentary behavior are related to poorer health outcomes in breast cancer survivors. However, few studies examining these behaviors in survivors have used objective measures, considered activities other than moderate-to-vigorous intensity activity (MVPA) and/or sedentary behavior (i.e. low intensity activities) or compared survivors to healthy controls. The purpose of the present study is to compare accelerometer-measured activity of various intensities (total, light, lifestyle, MVPA) and sedentary behavior between breast cancer survivors and non-cancer controls.
  
  
  METHODS
  An imputation-based approach of independent sample t-tests adjusting for multiple comparisons was used to compare estimates of participation in each activity and sedentary behavior between survivors [n=398; M(SD)age=56.95 (9.11)] and block-matched non-cancer controls [n=1120; M(SD)age=54.88 (16.11)]. Potential moderating effects of body mass index (BMI), age, and education were also examined.
  
  
  RESULTS
  Breast cancer survivors registered less daily total (282.8 v. 346.9) light (199.1 v. 259.3) and lifestyle (62.0 v. 71.7) activity minutes and more MVPA (21.6 v. 15.9) and sedentary behavior (555.7 v. 500.6) minutes than controls (p<0.001 for all). These relationships were largely consistent across BMI, age and education. On average, survivors spent an estimated 66.4% of their waking time sedentary and 31.1% in light/lifestyle activity and 2.6% in MVPA.
  
  
  CONCLUSIONS
  Breast cancer survivors are more sedentary and participate in less low intensity activity than controls. Although survivors registered more MVPA, these levels were insufficient. Future research should explore these differences and potential benefits of targeting low intensity activities and reducing sedentary time in this population.
authors.affiliation: Department of Preventive Medicine, Northwestern University, United States. Electronic address: smphillips@northwestern.edu.
authors.forename: Siobhan M
authors.initials: SM
authors.lastname: Phillips
authors.affiliation: Division of Cancer Prevention, National Cancer Institute, United States.
authors.forename: Kevin W
authors.initials: KW
authors.lastname: Dodd
authors.affiliation: Department of Kinesiology, University of Wisconsin-Milwaukee, United States.
authors.forename: Jeremy
authors.initials: J
authors.lastname: Steeves
authors.affiliation: Division of Cancer Control and Population Science, National Cancer Institute, United States.
authors.forename: James
authors.initials: J
authors.lastname: McClain
authors.affiliation: Division of Cancer Control and Population Science, National Cancer Institute, United States.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Alfano
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois Urbana-Champaign, United States.
authors.forename: Edward
authors.initials: E
authors.lastname: McAuley
mesh_terms: D061725:Accelerometry / Q000295:instrumentation / Q000379:methods; D000328:Adult; D001943:Breast Neoplasms / Q000473:pathology / Q000503:physiopathology* / Q000534:rehabilitation*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000295:instrumentation / Q000379:methods; D009043:Motor Activity / Q000502:physiology*; D009367:Neoplasm Staging; D011379:Prognosis; D057185:Sedentary Behavior; D017741:Survivors
keywords: Breast cancer survivors; Exercise; Physical activity; Sedentary behavior