title: Measuring physical activity self-regulation strategies in older adults.
abstract: BACKGROUND
  Theoretically, self-regulatory strategies (e.g., goal setting, self-monitoring) are an important influence of behavior change, but very little research has examined the relationship between self-regulation and physical activity (PA) behavior. Petosa's (1993) 43-item PA self-regulation scale (PASR-43) affords the opportunity for studying this construct in the context of PA; however the PASR-43 has not been tested for structural aspects of validity. Therefore, this study examines the structural validity of the PASR-43 in older adults.
  
  
  METHODS
  The structural validity of the PASR-43 was tested in a large sample of older adults from North and South Carolina and Ohio (N = 460) using maximum likelihood estimation and confirmatory factor analysis in AMOS 5.0.
  
  
  RESULTS
  The original 6-factor model for the PASR-43 scale did not represent an acceptable fit to the data (chi2 = 4732.25, df = 845, P < .0001, RMSEA = 0.10, NNFI = 0.67, CFI = 0.71). Based on a post hoc specification search, iterative model modifications resulted in a 12-item PA self-regulation scale (PASR-12) that represented an excellent fit to the data (chi2 = 70.75, df = 39, P = .001, RMSEA = 0.04, NNFI = 0.98, CFI = 0.99).
  
  
  CONCLUSIONS
  The PASR-12 provides a concise and valid measure of PA self-regulation for use with older adults. Future studies should cross-validate the PASR-12 and examine invariance across time and between age, ethnic, gender, and geographical groups.
authors.affiliation: Dept. of Health Science, University of Alabama, Tuscaloosa, AL, USA.
authors.forename: Michelle Renee
authors.initials: MR
authors.lastname: Umstattd
authors.forename: Rob
authors.initials: R
authors.lastname: Motl
authors.forename: Sara
authors.initials: S
authors.lastname: Wilcox
authors.forename: Ruth
authors.initials: R
authors.lastname: Saunders
authors.forename: Melissa
authors.initials: M
authors.lastname: Watford
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015444:Exercise / Q000523:psychology; D005163:Factor Analysis, Statistical; D005260:Female; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D008875:Middle Aged; D008960:Models, Psychological; D009657:North Carolina; D009820:Ohio; D015203:Reproducibility of Results; D020377:Self Efficacy; D012927:Social Control, Informal; D012944:Social Support; D013022:South Carolina; D011795:Surveys and Questionnaires