Mobile App-Based Small-Group Physical Activity Intervention for Young African American Women: a Pilot Randomized Controlled Trial

A lack of adequate physical activity among young African American women remains a serious public health challenge. Few evidence-based interventions are available to increase physical activity in this population, and none has leveraged mobile technologies, even though African Americans are among the most avid users of mobile applications (apps). We conducted a pilot randomized controlled trial to test the efficacy of a mobile app-based small-group intervention in increasing physical activity among African American women aged 18 to 35years (N=91) in Philadelphia, PA. Cohorts of eight participants were randomized in a 1:1 ratio to a 4-women small-group intervention or an individual control condition. Control participants used the app to track their own activities. Small-group participants could track their own activities and those of the other three women in their group and could message the other women using a chatting tool. The primary outcome was meeting the goal of engaging in at least 90min/day of light physical activity during the 3-month study period objectively assessed by a Fitbit device. Data were collected in 2016 and analyzed in 2017. Group participants had higher odds of meeting the goal (OR=1.48, p=.048) than did control participants, an effect that did not wane during the 3-month study period. Irrespective of condition, participants had lower body-mass index (p=.01) and performed more push-ups (p<.0001) at the 1-month and 3-month assessments compared with the baseline measures. Mobile apps facilitating small online groups can contribute to efforts to increase physical activity among young African American women.This study is registered at www.clinicaltrials.gov NCT02736903.