ABSTRACT
AIM: This study investigated correlations between objectively measured physical activity (PA) and smartphone and tablet usage by sex and age in subjects aged eight, 11 and 14. METHODS: We recruited 549 children and adolescents (264 boys) from six schools in three middle-class communities in south-eastern Sweden. Steps per day were objectively measured using sealed pedometers and a brief daily questionnaire about smartphone and tablet usage. Correlations between mean steps per day and mean daily minutes of smartphone and tablet usage, and differences between low and high users, were investigated. RESULTS: There was a moderately inverse correlation between steps per day and smartphone and tablet usage in the total sample (r = -.329, P < .001), but it was lower in boys (r = -.340, P < .001) than girls (r = -.401, P < .001). When stratified further by both sex and age, this correlation was only found among 14-year-old girls (r = -.385, P < .001) and this group only, differences between low and high users (P = .005) were seen. CONCLUSION: There was a moderately inverse correlation between steps per day and smartphone and tablet usage. When stratified by both sex and age groups, this correlation was only observed in 14-year-old girls. The results may have implications for future PA interventions that target adolescent girls.
