title: Physical activity and sedentary time in relation to academic achievement in children.
abstract: OBJECTIVE
  To investigate the independent and combined associations of objectively measured moderate-to-vigorous physical activity (MVPA) and sedentary time (ST) with reading and arithmetic skills.
  
  
  METHODS
  Cross-sectional/prospective.
  
  
  METHODS
  Participants were 89 boys and 69 girls aged 6-8 years. MVPA and ST were measured using a combined heart rate and movement sensor and body fat percentage by dual-energy X-ray absorptiometry in Grade 1. Reading fluency, reading comprehension, and arithmetic skills were assessed using standardized tests in Grades 1-3. The data were analyzed using linear regression analyses and analyses of covariance with repeated measures.
  
  
  RESULTS
  In boys, MVPA was directly and ST inversely associated with reading fluency in Grades 1-3 and arithmetic skills in Grade 1 (P<0.05). Higher levels of MVPA were also related to better reading comprehension in Grade 1 (P<0.05). Most of the associations of MVPA and ST with reading and arithmetic skills attenuated after mutual adjustment for MVPA or ST. Furthermore, boys with a combination of lower levels of MVPA and higher levels of ST had consistently poorer reading fluency (P=0.002) and reading comprehension (P=0.027) across Grades 1-3 than other boys. In girls, ST was directly associated with arithmetic skills in Grade 2 (P<0.05). However, this relationship of ST with arithmetic skills was no longer significant after adjustment for body fat percentage.
  
  
  CONCLUSIONS
  Lower levels of MVPA and higher levels of ST and particularly their combination were related to poorer reading skills in boys. In girls, higher levels of ST were related to better arithmetic skills.
authors.affiliation: Institute of Biomedicine/Physiology, University of Eastern Finland, Kuopio Campus, Finland; Childhood Health and Active Living Research Group, Department of Biology of Physical Activity, University of Jyväskylä, Finland. Electronic address: eero.haapala@uef.fi.
authors.forename: Eero A
authors.initials: EA
authors.lastname: Haapala
authors.affiliation: Institute of Biomedicine/Physiology, University of Eastern Finland, Kuopio Campus, Finland; Institute of Dentistry, University of Eastern Finland, Kuopio Campus, Finland.
authors.forename: Juuso
authors.initials: J
authors.lastname: Väistö
authors.affiliation: Institute of Biomedicine/Physiology, University of Eastern Finland, Kuopio Campus, Finland.
authors.forename: Niina
authors.initials: N
authors.lastname: Lintu
authors.affiliation: MRC Epidemiology Unit, University of Cambridge, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge Biomedical Campus, United Kingdom.
authors.forename: Kate
authors.initials: K
authors.lastname: Westgate
authors.affiliation: MRC Epidemiology Unit, University of Cambridge, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge Biomedical Campus, United Kingdom; Department of Sport Medicine, Norwegian School of Sports Science, Norway.
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
authors.affiliation: Department of Teacher Education, University of Jyväskylä, Finland.
authors.forename: Anna-Maija
authors.initials: AM
authors.lastname: Poikkeus
authors.affiliation: MRC Epidemiology Unit, University of Cambridge, University of Cambridge School of Clinical Medicine, Institute of Metabolic Science, Cambridge Biomedical Campus, United Kingdom.
authors.forename: Soren
authors.initials: S
authors.lastname: Brage
authors.affiliation: Institute of Biomedicine/Physiology, University of Eastern Finland, Kuopio Campus, Finland; Department of Clinical Physiology and Nuclear Medicine, University of Eastern Finland, Kuopio Campus, Finland; Kuopio Research Institute of Exercise Medicine, Finland.
authors.forename: Timo A
authors.initials: TA
authors.lastname: Lakka
mesh_terms: D000076363:Academic Success; D061725:Accelerometry; D002648:Child; D003430:Cross-Sectional Studies; D015444:Exercise / Q000523:psychology*; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D008433:Mathematics; D011446:Prospective Studies; D011932:Reading; D057185:Sedentary Behavior
keywords: Academic performance; Cognition; Motor activity; Pediatrics; Sedentary behavior