title: Promoting Physical Activity in Low-Active Adolescents via Facebook: A Pilot Randomized Controlled Trial to Test Feasibility.
abstract: BACKGROUND
  The World Wide Web is an effective method for delivering health behavior programs, yet major limitations remain (eg, cost of development, time and resource requirements, limited interactivity). Social media, however, has the potential to deliver highly customizable and socially interactive behavioral interventions with fewer constraints. Thus, the evaluation of social media as a means to influence health behaviors is warranted.
  
  
  OBJECTIVE
  The objective of this trial was to examine and demonstrate the feasibility of using an established social networking platform (ie, Facebook) to deliver an 8 week physical activity intervention to a sample of low-active adolescents (N=21; estimated marginal mean age 13.48 years).
  
  
  METHODS
  Participants were randomized to either an experimental (ie, Behavioral) or attentional control (ie, Informational) condition. Both conditions received access to a restricted-access, study-specific Facebook group where the group's administrator made two daily wall posts containing youth-based physical activity information and resources. Primary outcomes included physical activity as assessed by accelerometry and self-report. Interactions and main effects were examined, as well as mean differences in effect sizes.
  
  
  RESULTS
  Analyses revealed significant improvements over time on subjectively reported weekly leisure-time physical activity (F1,18=8.426, P=.009, η2 = .319). However, there was no interaction between time and condition (F1,18=0.002, P=.968, η2 = .000). There were no significant time or interaction effects among the objectively measured physical activity variables. Examination of effect sizes revealed moderate-to-large changes in physical activity outcomes.
  
  
  CONCLUSIONS
  Results provide initial support for the feasibility of delivery of a physical activity intervention to low-active adolescents via social media. Whether by employing behavioral interventions via social media can result in statistically meaningful changes in health-related behaviors and outcomes remains to be determined.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT01870323; http://clinicaltrials.gov/show/NCT01870323 (Archived by WebCite at http://www.webcitation.org/6SUTmSeZZ).
authors.affiliation: Bellarmine University, Exercise Science Department, Bellarmine University, Louisville, KY, United States. twojcicki@bellarmine.edu.
authors.forename: Thomas R
authors.identifier: http://orcid.org/0000-0001-6320-413X
authors.initials: TR
authors.lastname: Wójcicki
authors.forename: Diana
authors.identifier: http://orcid.org/0000-0003-0796-7284
authors.initials: D
authors.lastname: Grigsby-Toussaint
authors.forename: Charles H
authors.identifier: http://orcid.org/0000-0002-3722-5612
authors.initials: CH
authors.lastname: Hillman
authors.forename: Marian
authors.identifier: http://orcid.org/0000-0003-4485-4422
authors.initials: M
authors.lastname: Huhman
authors.forename: Edward
authors.identifier: http://orcid.org/0000-0002-4574-3292
authors.initials: E
authors.lastname: McAuley
keywords: adolescents; behavior change; feasibility; physical activity; randomized controlled trial; social media