title: Physical activity, sedentary behavior, and academic performance in Finnish children.
abstract: OBJECTIVE
  This study aimed to determine the relationships between objectively measured and self-reported physical activity, sedentary behavior, and academic performance in Finnish children.
  
  
  METHODS
  Two hundred and seventy-seven children from five schools in the Jyväskylä school district in Finland (58% of the 475 eligible students, mean age = 12.2 yr, 56% girls) participated in the study in the spring of 2011. Self-reported physical activity and screen time were evaluated with questions used in the WHO Health Behavior in School-Aged Children study. Children's physical activity and sedentary time were measured objectively by using an ActiGraph GT1M/GT3X accelerometer for seven consecutive days. A cutoff value of 2296 counts per minute was used for moderate-to-vigorous physical activity (MVPA) and 100 counts per minute for sedentary time. Grade point averages were provided by the education services of the city of Jyväskylä. ANOVA and linear regression analysis were used to analyze the relationships among physical activity, sedentary behavior, and academic performance.
  
  
  RESULTS
  Objectively measured MVPA (P = 0.955) and sedentary time (P = 0.285) were not associated with grade point average. However, self-reported MVPA had an inverse U-shaped curvilinear association with grade point average (P = 0.001), and screen time had a linear negative association with grade point average (P = 0.002), after adjusting for sex, children's learning difficulties, highest level of parental education, and amount of sleep.
  
  
  CONCLUSIONS
  In this study, self-reported physical activity was directly, and screen time inversely, associated with academic achievement. Objectively measured physical activity and sedentary time were not associated with academic achievement. Objective and subjective measures may reflect different constructs and contexts of physical activity and sedentary behavior in association with academic outcomes.
authors.affiliation: 1Research Center for Sport and Health Sciences, LIKES-Research Center for Sport and Health Sciences, Jyväskylä, FINLAND; 2University of Jyväskylä, Jyväskylä, FINLAND; and 3Department of Epidemiology and Biostatistics, MRC-HPA Centre for Environment and Health, Imperial College London, London, UNITED KINGDOM.
authors.forename: Heidi J
authors.initials: HJ
authors.lastname: Syväoja
authors.forename: Marko T
authors.initials: MT
authors.lastname: Kantomaa
authors.forename: Timo
authors.initials: T
authors.lastname: Ahonen
authors.forename: Harto
authors.initials: H
authors.lastname: Hakonen
authors.forename: Anna
authors.initials: A
authors.lastname: Kankaanpää
authors.forename: Tuija H
authors.initials: TH
authors.lastname: Tammelin
mesh_terms: D061725:Accelerometry; D002648:Child; D004521:Educational Measurement; D004522:Educational Status; D005260:Female; D005387:Finland; D006801:Humans; D008297:Male; D009043:Motor Activity; D057185:Sedentary Behavior; D057566:Self Report; D013690:Television; D018910:Video Games