Designing a Mobile App to Promote Physical Activity in Adolescents

Thesis Abstract

The escalating prevalence of sedentary lifestyles among adolescents presents a significant public health challenge, with declining physical activity levels linked to increased risks of obesity, cardiovascular diseases, and mental health issues. This study addresses the urgent need for innovative, scalable interventions to promote physical activity within this demographic by harnessing mobile technology. The primary aim is to design, develop, and evaluate a user-centered mobile application that motivates and facilitates increased physical activity among adolescents aged 13 to 18 years. The study specifically seeks to identify the features that influence engagement, measure the app’s effectiveness in enhancing physical activity levels, and explore adolescents' perceptions of the technology’s usability and motivational impact. Employing a mixed-methods research design, the study integrates quantitative and qualitative approaches to ensure comprehensive insights. The quantitative component follows an experimental quasi-design involving a sample of 300 adolescents recruited from three secondary schools using stratified random sampling. Participants are assigned to intervention and control groups, with the intervention group provided access to the mobile app over a 12-week period. Data collection instruments include a modified International Physical Activity Questionnaire (IPAQ) for baseline and post-intervention activity measurement, and a user engagement questionnaire adapted from the User Engagement Scale (UES). The qualitative data derive from focus group discussions and semi-structured interviews with 30 participants from the intervention group conducted at mid-point and after completion to capture experiential insights. Validity and reliability of instruments are established through pilot testing and Cronbach’s alpha coefficients exceeding 0.8. Data analysis proceeds via descriptive statistics to profile participant demographics, followed by inferential tests including paired sample t-tests and ANCOVA to assess differences in physical activity levels pre- and post-intervention. Multiple regression analysis is employed to identify predictors of app engagement and efficacy. Thematic analysis, guided by the Self-Determination Theory and the Theory of Planned Behavior, is used to interpret qualitative data, revealing motivational factors, perceived barriers, and user preferences that influence app utilization and physical activity behaviors. Expected findings indicate a statistically significant increase in physical activity levels among adolescents in the intervention group, with higher engagement correlating with perceived autonomy and social connectivity features within the app. The study anticipates identifying specific design features—such as gamification, social integration, and goal-setting functionalities—that are critical for sustained usage. The integration of theories provides a framework for understanding motivational dynamics and behavioral change mechanisms influenced by the app. The results are expected to demonstrate that a theoretically grounded, adolescent-oriented mobile application can effectively promote physical activity and maintain user engagement over a sustained period. This research makes a substantial contribution to knowledge by providing evidence-based guidelines for developing mobile health interventions tailored to adolescents, integrating behavioral theories with design practices. It offers a model for deploying technology-driven strategies in physical activity promotion, emphasizing user-centered design elements informed by empirical data. The study further advances understanding of the relationship between technological engagement and health behavior change in adolescents. The main conclusion underscores the potential of well-designed mobile applications to serve as effective tools in promoting physical activity among youth, especially when grounded in behavioral theory and user engagement principles. Recommendations include scaling the app for broader deployment across diverse adolescent populations, integrating parental and school-based support mechanisms, and conducting longitudinal studies to assess sustained behavioral change. Future research avenues suggested involve exploring integration with wearable devices and personalized feedback systems to further enhance motivation and adherence. This study ultimately contributes to the development of innovative, technology-enabled solutions aimed at mitigating the health risks associated with physical inactivity among adolescents.