Effect of Excessive Screen Time on Cardiorespiratory Fitness in Children: A Longitudinal Study

This study investigated the effect of different components of screen time (mobile phone use, TV/video viewing, and video gaming) on cardiorespiratory fitness (CRF) development in children aged 9-12 years.

This was a two-year longitudinal study conducted with 175 children (49.7% girls, mean age = 9.5) in Japan. CRF was assessed using a 20 m shuttle run test conducted at baseline and again at follow-up. Children were categorized as "Good" or "Poor" based on the change in CRF scores for each gender. Screen time was assessed using a self-reported questionnaire at baseline and termed as "high" if children reported ≥ 2 h/day. Univariate and multivariate logistic regression analyses were performed after adjusting for gender, physical activity, and time of data collection.

Children scoring "high" on mobile phone use had lower odds of being categorized as "Good" in CRF change (crude odds ratio (OR): 0.34; 95% confidence interval (CI): 0.15-0.90 (adjusted OR: 0.33; 95% CI: 0.12-0.91)). There were no significant effects of TV/video viewing (crude OR: 1.54; 95% CI: 0.84-2.81) and video gaming (crude OR: 0.98; 95% CI: 0.48-1.97) on changes in CRF.

Limiting excessive mobile phone usage might be important for ensuring healthy development of CRF in children.