Screen time and physical activity in youth: thief of time or lifestyle choice?

BACKGROUND This study aimed to examine the relationship between screen time and physical activity (PA) in children and adolescents but also to determine specific elements of PA that were most closely associated with screen time. METHODS We studied a cross-sectional sample of 6176 10.0-15.9 year olds (53% boys, 12.9 ± 1.5 years) who completed the Physical Activity Questionnaire for Children/Adolescents and reported daily screen time. Differences in total PA and specific elements of PA were examined between groups reporting: < 2 h, 2-4 h, and > 4 h daily screen time. RESULTS There were significant differences between screen time groups in: total PA, number of bouts of PA reported, after school PA, evening PA and weekend PA (P < .0001). There was a graded, negative association between higher screen time and lower free-time PA. Participants reporting < 2 h screen time were also significantly more active during school lunch breaks than those reporting > 2 h. Boys reporting > 4 h screen time were less active during physical education lessons. CONCLUSIONS Screen time is significantly and negatively associated with PA in British youth. Screen time may displace active pursuits out of school but is also associated with lower PA during school. Daily screen time should be limited to < 2 h in line with current recommendations.