Background: Sedentary behavior (SB) increases throughout adolescence, and is associated with adverse health outcomes.
Purpose: Examine psychosocial and friend influences on SB and screen time in adolescents using a mixed-methods design.
Methods: 108 middle and high school students wore accelerometers to measure objective SB, completed screen time and psychosocial questionnaires, and nominated friends to complete activity questionnaires. Focus groups centered around influences on SB behavior. Regression analyses and NVivo software analyzed quantitative and qualitative data.
Results: Screen time was associated with greater screen time enjoyment, lower self-efficacy, and friends' screen time (r2 = .21, P < .0001). Friends influenced whether adolescents engaged in screen time behaviors, with active friends encouraging less screen time.
Conclusion: Active friends influenced adolescents to engage in less SB. Interventions should place an emphasis on encouraging less screen time, and providing opportunities for adolescents and their friends to engage in activities that promote physical activity rather than SB.
Keywords: accelerometry; adolescents; physical activity; qualitative research.