title: Associations between screen time and physical activity among Spanish adolescents.
abstract: BACKGROUND
  Excessive time in front of a single or several screens could explain a displacement of physical activity. The present study aimed at determining whether screen-time is associated with a reduced level of moderate to vigorous physical activity (MVPA) in Spanish adolescents living in favorable environmental conditions.
  
  
  RESULTS
  A multi-stage stratified random sampling method was used to select 3503 adolescents (12-18 years old) from the school population of Gran Canaria, Spain. MVPA, screen-time in front of television, computer, video game console and portable console was assessed in the classroom by fulfilling a standardized questionnaire. Bivariate and multivariate logistic regression analyses adjusted by a set of social-environmental variables were carried out. Forty-six percent of girls (95% CI±2.3%) and 26% of boys (95% CI±2.1%) did not meet the MVPA recommendations for adolescents. Major gender differences were observed in the time devoted to vigorous PA, video games and the total time spent on screen-based activities. Boys who reported 4 hours•week(-1) or more to total screen-time showed a 64% (OR = 0.61, 95% CI, 0.44-0.86) increased risk of failing to achieve the recommended adolescent MVPA level. Participation in organized physical activities and sports competitions were more strongly associated with MVPA than screen-related behaviors.
  
  
  CONCLUSIONS
  No single screen-related behavior explained the reduction of MVPA in adolescents. However, the total time accumulated through several screen-related behaviors was negatively associated with MVPA level in boys. This association could be due to lower availability of time for exercise as the time devoted to sedentary screen-time activities increases. Participation in organized physical activities seems to counteract the negative impact of excessive time in front of screens on physical activity.
authors: Department of Physical Education, University of Las Palmas de Gran Canaria, Campus Universitario de Tafira s/n, Las Palmas de Gran Canaria, Spain. jserrano@def.ulpgc.es
authors: Jose A
authors: JA
authors: Serrano-Sanchez
authors: Sara
authors: S
authors: Martí-Trujillo
authors: Angela
authors: A
authors: Lera-Navarro
authors: Cecilia
authors: C
authors: Dorado-García
authors: Juan J
authors: JJ
authors: González-Henríquez
authors: Joaquín
authors: J
authors: Sanchís-Moysi
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D002947:Cities; D003201:Computers / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D016017:Odds Ratio; D015995:Prevalence; D013030:Spain / Q000453:epidemiology; D013690:Television / Q000706:statistics & numerical data*; D013997:Time Factors; D018910:Video Games / Q000706:statistics & numerical data*