title: Texting to Increase Adolescent Physical Activity: Feasibility Assessment.
abstract: Feasibility trials assess whether a behavior change program warrants a definite trial evaluation. This paper reports the feasibility of an intervention consisting of Self Determination Theory-informed text messages, pedometers, and goal prompts to increase adolescent physical activity.
  
  
  
  A 4-group randomized design with baseline and immediate post-study assessments was used. Groups (pedometer; pedometer + goal prompt; pedometer + goal prompt + theory-informed texts; no-treatment control) were systematically varied to assess the additive effect of intervention components on objectively measured physical activity (ie, ActiGraph). The primary outcome of the 12-week intervention was program feasibility. Changes in average daily step counts and minutes of moderate-to-vigorous physical activity also were examined. Post-intervention research with a subset of participants examined program reactions.
  
  
  
  Participants (N = 160) were evenly split by sex, mostly 14-15 years old, and of diverse race/ethnicity. Feasibility criteria were met. The attrition rate was less than 2%. Modest increases in average daily step counts and moderate-to-vigorous physical activity were observed in all groups except the control group. Participants reported positive reactions to the intervention.
  
  
  
  An intervention consisting of pedometers, theory-informed texts, and goal prompts, is a feasible and acceptable method for promoting physical activity to adolescents.
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA. dit@bcm.edu.
authors.forename: Debbe
authors.initials: D
authors.lastname: Thompson
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Dora
authors.initials: D
authors.lastname: Cantu
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Betsy
authors.initials: B
authors.lastname: Ramirez
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Karen W
authors.initials: KW
authors.lastname: Cullen
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Tom
authors.initials: T
authors.lastname: Baranowski
authors.affiliation: Department of Pediatrics, University of Washington School of Medicine, Seattle, Washington, USA.
authors.forename: Jason
authors.initials: J
authors.lastname: Mendoza
authors.affiliation: Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Barbara
authors.initials: B
authors.lastname: Anderson
authors.affiliation: Centre for Exercise, Nutrition & Health Sciences, School for Policy Studies, University of Bristol, Bristol, UK.
authors.forename: Russell
authors.initials: R
authors.lastname: Jago
authors.affiliation: Department of Physical Education and Recreation, University of Alberta, Edmonton, AB, Canada.
authors.forename: Wendy
authors.initials: W
authors.lastname: Rodgers
authors.affiliation: USDA/ARS Children's Nutrition Research Center, Baylor College of Medicine, Houston, TX, USA.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D015444:Exercise / Q000523:psychology; D005240:Feasibility Studies; D005260:Female; D006293:Health Promotion / Q000379:methods*; D006801:Humans; D008297:Male; D060145:Text Messaging