Digital Parent–Child Intervention on Children’s Exercise Behavior and Psychological Development—A Randomized Controlled Trial Based on Family Perspective

<b>Objective:</b> From a family perspective, this study aimed to examine the effects of a 12-week digital platform-based parent-child exercise intervention on children's behavioral level (physical activity), psychological level (physical exercise attitude), and mental health. <b>Methods:</b> This study included 218 students aged 10-11 years who underwent a 12-week standardized parent-child exercise intervention. The intervention group completed two structured parent-child tasks per week through a digital platform (Ding Talk App) while maintaining regular physical education classes; the control group only maintained their regular physical education classes. Assessments were conducted using the Physical Activity Rating Scale, Exercise Attitude Scale, and mental health scales (The Spence Children's Anxiety Scale (SCAS) and The Patient Health Questionnaire-9 (PHQ-9)) at four stages: pre-intervention (T1), mid-intervention (T2), post-intervention (T3), and a 2-month follow-up period (T4). The intervention effects and effect sizes (ηp²) were examined using Repeated Measures Analysis of Variance. <b>Results:</b> At the behavioral level, a significant group × time interaction was found for physical activity volume (F = 17.651, <i>p</i> = 0.04, ηp² = 0.138), indicating the presence of a moderate effect. At the psychological level, significant interactions were observed across exercise attitude dimensions (behavioral attitude: F = 3.699, <i>p</i> = 0.002, ηp² = 0.033; perceived behavioral control: F = 4.189, <i>p</i> = 0.006, ηp² = 0.037; subjective norm: F = 4.616, <i>p</i> < 0.001, ηp² = 0.040) and mental health measures (depression: F = 4.009, <i>p</i> = 0.026, ηp² = 0.044; anxiety: F = 3.1, <i>p</i> = 0.016, ηp² = 0.020), though no significant effect was found for behavioral intention (F = 1.346, <i>p</i> = 0.259, ηp² = 0.012), with all significant effects being relatively weak. <b>Conclusions:</b> The home-school collaborative, digital platform-based parent-child exercise intervention demonstrated positive effects on children's physical activity volume, exercise attitudes, and mental health, offering a feasible and promising strategy to support more integrated child health promotion initiatives.