Screen Time, Fatigue, Obesity and Physical Inactivity: Health Correlates of Problematic Smartphone Use in Adolescents.

The cross-sectional design means associations cannot be interpreted as causal; it is unclear whether problematic smartphone use leads to fatigue and inactivity, or vice versa. Participants with neurodevelopmental disorders, physical disabilities, chronic medical conditions, and potential eating disorders were excluded, so findings do not generalize to adolescents with these common comorbidities. Physical activity and sports participation were self-reported, which may introduce recall bias despite validation against school records. The study did not capture the qualitative aspects of smartphone use, such as content type or usage context, which may be relevant to intervention planning.

The authors declared no potential conflicts of interest and reported no funding.

Do not conclude that sports participation prevents problematic smartphone use based on these data. The study is cross-sectional, so the association between years of sports practice and lower odds of problematic use may reflect reverse causality or confounding by other lifestyle factors.