title: Social cognitive mediators of the effect of the MobileMums intervention on physical activity.
abstract: OBJECTIVE
  To explore whether improvements in physical activity following the MobileMums intervention were mediated by changes in Social Cognitive Theory (SCT) constructs targeted in the intervention (barrier self efficacy, goal setting skills, outcome expectancy, social support, and perceived environmental opportunity for exercise). This paper also examined if the mediating constructs differed between initial (baseline to 6 weeks) and overall (baseline to 13 weeks) changes in physical activity.
  
  
  METHODS
  Secondary analysis of data from a randomized controlled trial involving 88 postnatal women (<12 months postpartum). Participants were randomized to receive either the 12-week MobileMums intervention or a minimal-contact control condition. Physical activity and proposed mediators were assessed by self-report at baseline, 6 weeks, and 13 weeks. Walking for Exercise frequency was assessed using the Australian Women's Activity Survey and frequency of moderate-to-vigorous physical activity (MVPA) was assessed using a single-item question.
  
  
  RESULTS
  Initial improvements in goal-setting skills mediated the relationship between experimental condition and initial changes in MVPA, αβ (95% CI) = 0.23(0.01, 0.59), and Walking for Exercise, αβ (95% CI) = 0.34(0.06, 0.73). Initial improvements in barrier self efficacy mediated the relationship between experimental condition and initial change in MVPA, αβ (95% CI) = 0.36(0.12, 0.65), but not Walking for Exercise. None of the SCT outcomes significantly mediated the relationship between experimental condition and overall (baseline to 13 weeks) change in frequency of MVPA or Walking for Exercise.
  
  
  CONCLUSIONS
  Future interventions with postnatal women using SCT should target barrier self-efficacy and goal setting skills in order to increase physical activity.
authors.affiliation: Faculty of Health Sciences, School of Population Health, Cancer Prevention Research Centre, The University of Queensland, Queensland, Australia. b.fjeldsoe@sph.uq.edu.au
authors.forename: Brianna S
authors.initials: BS
authors.lastname: Fjeldsoe
authors.forename: Yvette D
authors.initials: YD
authors.lastname: Miller
authors.forename: Alison L
authors.initials: AL
authors.lastname: Marshall
mesh_terms: D000328:Adult; D001315:Australia; D015444:Exercise / Q000523:psychology*; D005260:Female; D005500:Follow-Up Studies; D006040:Goals; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D011181:Postnatal Care / Q000379:methods*; D015397:Program Evaluation; D011582:Psychological Theory; D020377:Self Efficacy; D057566:Self Report; D012944:Social Support; D016138:Walking / Q000523:psychology; D055815:Young Adult