title: Randomized controlled trial of collaborative implementation intentions targeting working adults' physical activity.
abstract: OBJECTIVE
  The research tested the efficacy of planning and partner-based interventions to promote physical activity over six months.
  
  
  METHODS
  Local government (council) employees (N = 257) were randomly allocated to one of four conditions (collaborative implementation intentions; partner-only; implementation intentions; control group) before completing measures at baseline and follow-ups at 1, 3 and 6 months. Outcome measures comprised validated self-report measures of physical activity: the international physical activity questionnaire (IPAQ; Craig et al., 2003) and self-report walking and exercise tables (SWET; Prestwich et al., 2012); psychosocial mediators (enjoyment, intention, self-efficacy, social influence); weight and waist size (baseline and 6 months only).
  
  
  RESULTS
  As well as losing the most weight, there was evidence that participants in the collaborative implementation-intention group were more physically active than each of the other three groups at 1-, 3- and 6-month follow-ups. Those in the implementation-intention and partner-only conditions did not outperform the control group on most measures.
  
  
  CONCLUSIONS
  Collaborative implementation intentions represent a potentially useful intervention to change important health behaviors that help reduce weight.
authors.affiliation: Institute of Psychological Sciences, University of Leeds, UK. a.j.prestwich@leeds.ac.uk
authors.forename: Andrew
authors.initials: A
authors.lastname: Prestwich
authors.forename: Mark T
authors.initials: MT
authors.lastname: Conner
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Lawton
authors.forename: Jane K
authors.initials: JK
authors.lastname: Ward
authors.forename: Karen
authors.initials: K
authors.lastname: Ayres
authors.forename: Rosemary R C
authors.initials: RR
authors.lastname: McEachan
mesh_terms: D000328:Adult; D003299:Cooperative Behavior; D015444:Exercise / Q000523:psychology*; D005260:Female; D015438:Health Behavior; D006801:Humans; D033182:Intention; D007398:Interpersonal Relations; D008297:Male; D008875:Middle Aged; D010379:Peer Group; D020377:Self Efficacy; D011795:Surveys and Questionnaires; D016138:Walking; D015431:Weight Loss; D017132:Workplace