Physical activity and screen time in children and adolescents in a medium size town in the South of Brazil.

Objective: To analyze the associations between sex and age with behaviour related to physical activity practice and sedentary behaviour in children and adolescents.

Methods: A cross-sectional study with 480 (236 boys) subjects enrolled in a public school in the city of Londrina, in the south of Brazil, aged 8-17 years. Measures of physical activity, sports practice and screen times were obtained using the Physical Activity Questionnaire for Older Children. The Mann-Whitney U test was used to compare variables between boys and girls. The Chi squared test was used for categorical analysis and Poisson regression was used to identify prevalence.

Results: Girls (69.6%; PR=1.05 [0.99-1.12]) spent more time with sedentary behaviour than boys (62.2%). Boys (80%; PR=0.95 [0.92-0.98]) were more physically active than girls (91%). Older students aged 13-17 showed a higher prevalence of physical inactivity (91.4%; PR=1.06 [1.02-1.10]) and time spent with sedentary behaviour of ≥2h/day (71.8%; PR=0.91 [0.85-0.97]) when compared to younger peers aged 8-12 (78.7 and 58.5%, respectively).

Conclusions: The prevalence of physical inactivity was higher in girls. Older students spent more screen time in comparison to younger students.