title: Effectiveness of a School-Based Physical Activity Intervention on Cognitive Performance in Danish Adolescents: LCoMotion-Learning, Cognition and Motion - A Cluster Randomized Controlled Trial.
abstract: BACKGROUND
  Physical activity is associated not only with health-related parameters, but also with cognitive and academic performance. However, no large scale school-based physical activity interventions have investigated effects on cognitive performance in adolescents. The aim of this study was to describe the effectiveness of a school-based physical activity intervention in enhancing cognitive performance in 12-14 years old adolescents.
  
  
  METHODS
  A 20 week cluster randomized controlled trial was conducted including seven intervention and seven control schools. A total of 632 students (mean (SD) age: 12.9 (0.6) years) completed the trial with baseline and follow-up data on primary or secondary outcomes (74% of randomized subjects). The intervention targeted physical activity during academic subjects, recess, school transportation and leisure-time. Cognitive performance was assessed using an executive functions test of inhibition (flanker task) with the primary outcomes being accuracy and reaction time on congruent and incongruent trials. Secondary outcomes included mathematics performance, physical activity levels, body-mass index, waist-circumference and cardiorespiratory fitness.
  
  
  RESULTS
  No significant difference in change, comparing the intervention group to the control group, was observed on the primary outcomes (p's>0.05) or mathematics skills (p>0.05). An intervention effect was found for cardiorespiratory fitness in girls (21 meters (95% CI: 4.4-38.6) and body-mass index in boys (-0.22 kg/m2 (95% CI: -0.39-0.05). Contrary to our predictions, a significantly larger change in interference control for reaction time was found in favor of the control group (5.0 milliseconds (95% CI: 0-9). Baseline to mid-intervention changes in physical activity levels did not differ significantly between groups (all p's>0.05).
  
  
  CONCLUSIONS
  No evidence was found for effectiveness of a 20-week multi-faceted school-based physical activity intervention for enhancing executive functioning or mathematics skills compared to a control group, but low implementation fidelity precludes interpretation of the causal relationship.
  
  
  BACKGROUND
  www.ClinicalTrials.gov NCT02012881.
authors.affiliation: Department of Sport Science and Clinical Biomechanics, Research Unit for Exercise Epidemiology, Centre of Research in Childhood Health, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
authors.forename: Jakob
authors.identifier: http://orcid.org/0000-0002-9186-7077
authors.initials: J
authors.lastname: Tarp
authors.affiliation: Department of Sport Science and Clinical Biomechanics, Research Unit for Exercise Epidemiology, Centre of Research in Childhood Health, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
authors.forename: Sidsel Louise
authors.initials: SL
authors.lastname: Domazet
authors.affiliation: Department of Sport Science and Clinical Biomechanics, Research Unit for Exercise Epidemiology, Centre of Research in Childhood Health, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
authors.forename: Karsten
authors.initials: K
authors.lastname: Froberg
authors.affiliation: Department of Kinesiology and Community Health, University of Illinois at Urbana-Champaign, 906 South Goodwin Avenue, Urbana-Champaign, Illinois, 61801, United States of America.
authors.forename: Charles H
authors.initials: CH
authors.lastname: Hillman
authors.affiliation: Department of Sport Science and Clinical Biomechanics, Research Unit for Exercise Epidemiology, Centre of Research in Childhood Health, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.|Department of Sports Medicine, Norwegian School of Sport Sciences, Oslo 0806, Norway.
authors.forename: Lars Bo
authors.initials: LB
authors.lastname: Andersen
authors.affiliation: Department of Sport Science and Clinical Biomechanics, Research Unit for Exercise Epidemiology, Centre of Research in Childhood Health, University of Southern Denmark, Campusvej 55, 5230 Odense M, Denmark.
authors.forename: Anna
authors.initials: A
authors.lastname: Bugge
mesh_terms: D000293:Adolescent; D000072599:Cardiorespiratory Fitness; D002648:Child; D003071:Cognition; D015444:Exercise; D005260:Female; D006801:Humans; D007858:Learning; D008297:Male; D012574:Schools; D013647:Task Performance and Analysis