Data from: Effectiveness of exercise snacks in mitigating adolescent problematic smartphone use: A four-wave cluster randomized controlled trial

This dataset contains de-identified longitudinal data from a four-wave cluster randomized controlled trial evaluating the effectiveness of a school-based exercise snacks intervention on mitigating problematic smartphone use among adolescents. The trial involved 386 participants and spanned six months. The dataset includes demographic variables, subjective smartphone addiction severity (SAS-SV), objective daily screen time, basic psychological need satisfaction (SDT), psychological distress (DASS-21), state-level well-being (WHO-5), and stable psychological traits (RSES, CYRM). Furthermore, it includes continuous objective physical activity metrics, specifically daily steps and calorie expenditure, captured via wearable devices. Data were collected at baseline, month 2, month 4 (end of intervention), and month 6 (follow-up).