title: Postpartum physical activity: measuring theory of planned behavior constructs.
abstract: OBJECTIVE
  To produce evidence for factor validity and longitudinal invariance of scales used to examine the theory of planned behavior applied to physical activity.
  
  
  METHODS
  Self-report questionnaires were administered at 3- (n = 267) and 12-months (n = 333) postpartum.
  
  
  RESULTS
  A single-factor model fit data from the normative beliefs, perceived behavioral control, and behavioral beliefs scales. Attitude and control beliefs were found to be multidimensional. Longitudinal invariance of all scales was supported.
  
  
  CONCLUSIONS
  Each scale had strong validity evidence. Future research using these measures will help identify areas for intervention and reveal how changes in these constructs influence physical activity.
authors.affiliation: Center for Health Promotion and Disease Prevention, University of North Carolina, Chapel Hill, NC 27599, USA. derekh@email.unc.edu
authors.forename: Derek
authors.initials: D
authors.lastname: Hales
authors.forename: Kelly R
authors.initials: KR
authors.lastname: Evenson
authors.forename: Fang
authors.initials: F
authors.lastname: Wen
authors.forename: Sara
authors.initials: S
authors.lastname: Wilcox
mesh_terms: D000293:Adolescent; D000328:Adult; D001294:Attitude to Health; D003469:Culture; D015444:Exercise / Q000523:psychology*; D005163:Factor Analysis, Statistical; D005260:Female; D015438:Health Behavior; D006801:Humans; D033182:Intention; D008962:Models, Theoretical; D009657:North Carolina; D049590:Postpartum Period / Q000523:psychology*; D011582:Psychological Theory; D015203:Reproducibility of Results; D020377:Self Efficacy; D011795:Surveys and Questionnaires; D055815:Young Adult