Effect of Fragmented Exercise Snacks on Mobile Phone Addiction and Psychophysical Health in Adolescents: A Randomized Controlled Trial

Inclusion Criteria

Inclusion Criteria: 1. Adolescents aged 12-18 years enrolled in the participating middle/high school. 2. Owner of a smartphone with daily usage time \> 2 hours. 3. Score on the Smartphone Addiction Scale-Short Version (SAS-SV) indicating a risk of addiction (e.g., score \> 31 for males, \> 33 for females). 4. Physically capable of participating in high-intensity exercise (PAR-Q screening negative). 5. Provided written informed consent (from both student and guardian). Exclusion Criteria: 1. Diagnosed with severe physical disabilities or cardiovascular diseases that contraindicate high-intensity exercise (e.g., congenital heart disease). 2. Currently participating in other professional sports training or weight loss programs. 3. Diagnosed with severe psychiatric disorders (e.g., severe depression, schizophrenia) requiring medication. 4. Taking medications that affect heart rate or cognitive function.