title: Adolescent physical activity: does implementation intention have a role?
abstract: BACKGROUND
  The current study tested the utility of an integrated social cognitive model to predict physical activity (PA) intentions and behavior in New Zealand adolescents.
  
  
  METHODS
  Seventy-two adolescents (mean age = 16.92, SD = 0.66) completed measures consistent with the integrated model (attitude, subjective norm, perceived behavioral control [PBC], goal intention, task-efficacy, barrier efficacy, and implementation intention). Pedometer data (Yamax SW200 pedometer) were collected for 7 days, and a self-report 7-day recall questionnaire was administered at the end of this week. A series of hierarchical regression analyses were conducted to examine the contribution of the model to PA goal intention, implementation intention, self-reported and objective PA.
  
  
  RESULTS
  The integrated model accounted for 41% of goal intention, 33% of implementation intention, and 41% and 18% of subjectively and objectively measured PA, respectively. PBC had the strongest association with goal intention whereas attitude had the strongest association with implementation intention. Task-efficacy made the greatest contribution to objectively measured PA, whereas implementation intention had the strongest association with subjectively measured PA.
  
  
  CONCLUSIONS
  These findings have implications regarding PA measurement in adolescent populations, and suggest that social cognitive variables play an important role in adolescent PA. Recommendations for future research are discussed.
authors.affiliation: Clinical Trials Research Unit, University of Auckland, Auckland, New Zealand.
authors.forename: Vaughan
authors.initials: V
authors.lastname: Roberts
authors.forename: Ralph
authors.initials: R
authors.lastname: Maddison
authors.forename: Jane
authors.initials: J
authors.lastname: Magnusson
authors.forename: Harry
authors.initials: H
authors.lastname: Prapavessis
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D008297:Male; D000294:Adolescent Behavior; D015444:Exercise / Q000502:physiology; D006040:Goals; D015438:Health Behavior; D033182:Intention; D007899:Leisure Activities / Q000523:psychology; D018670:Monitoring, Ambulatory; D010379:Peer Group; D012044:Regression Analysis; D020377:Self Efficacy