A decrease in physical activity as children age is a contributing factor to the U.S. obesity epidemic. Middle school children are particularly vulnerable to sedentary activities. Activity trackers show promise as a means to motivate children and adults to increase physical activity (PA). This study examined the effect of a text messaging intervention and use of activity trackers with a companion social website on the body mass index (BMI), body fat percentage, physical fitness, and PA self-efficacy of middle school children. Children aged 11-14 (n=102) were randomly assigned to one of three groups for a 10-week intervention: activity tracker group; text messaging group; activity tracker + text messaging group. Physical fitness, BMI, PA self-efficacy, and body fat percentage were measured before and after the intervention. Ninety-eight children (n-98) completed the study. There were no significant differences in physical fitness, BMI, PA self-efficacy, or body fat percentage in any of the three groups. This study gives no clear support to the hypothesis that use of activity trackers and a text messaging intervention have a positive effect on physical fitness, PA self-efficacy, or body fat percentage.

Date of publication

Spring 5-5-2017

Document Type




Persistent identifier


Committee members

Dr. Jenifer Chilton, Dr. Barbara Haas, Dr. Kevin Gosselin, Dr. David Criswell


Doctor of Philosophy in Nursing