Abstract
Introduction: Only 3.9% of adolescents met the WHO-recommended physical activity level, highlighting the need to understand contextual barriers in urban Tanzania. Physical inactivity during adolescence contributes to future non-communicable disease risk, yet evidence on contextual barriers remains limited. Guided by a socio-ecological perspective, this study assessed physical activity among school-going adolescents and examined social and environmental influences.
Methods: A convergent mixed-methods study was conducted in three public secondary schools in Kinondoni, Dar es Salaam, between July and November 2025. Quantitative data were collected from 381 adolescents aged 13-18 years selected through multistage and systematic sampling. Qualitative data were collected through three adolescent focus group discussions, three separate parent/guardian focus group discussions, and three physical education teacher interviews. Weekly physical activity was estimated from self-reported frequency and duration; at least 420 minutes/week was classified as meeting the WHO-recommended level. Quantitative data were analysed using univariable logistic regression, while qualitative data were analysed thematically.
Results: Fifteen adolescents (3.9%) met the recommendation. Adolescents aged 16-18 years had lower odds of meeting the recommendation than those aged 13-15 years (OR 0.19, 95% CI 0.04-0.85), while boys had higher odds than girls (OR 8.85, 95% CI 1.97-39.78). Parental encouragement was inversely associated with meeting the recommendation (OR 0.28, 95% CI 0.10-0.83). Qualitative findings identified academic pressure, gender norms, social influence, limited facilities, and safety concerns.
Conclusion: Interventions should address school, social, gender-related, and environmental barriers, particularly among girls and older adolescents.