title: Variation in population levels of physical activity in European children and adolescents according to cross-European studies: a systematic literature review within DEDIPAC.
abstract: BACKGROUND
  Regular physical activity is associated with physical, social and mental health benefits, whilst insufficient physical activity is associated with several negative health outcomes (e.g. metabolic problems). Population monitoring of physical activity is important to gain insight into prevalence of compliance to physical activity recommendations, groups at risk and changes in physical activity patterns. This review aims to provide an overview of all existing studies that measure physical activity in youth, in cross-European studies, to describe the variation in population levels of physical activity and to describe and define challenges regarding assessment methods that are used.
  
  
  METHODS
  A systematic search was performed on six databases (PubMed, EMBASE, CINAHL, PsycINFO, SportDiscus and OpenGrey), supplemental forward- and backward tracking was done and authors' and experts' literature databases were searched to identify relevant articles. Journal articles or reports that reported levels of physical activity in the general population of youth from cross-European studies were included. Data were reviewed, extracted and assessed by two researchers, with disagreements being resolved by a third researcher. The review protocol of this review is published under registration number CRD42014010684 in the PROSPERO database.
  
  
  RESULTS
  The search resulted in 9756 identified records of which 30 articles were included in the current review. This review revealed large differences between countries in prevalence of compliance to physical activity recommendations (i.e. 60 min of daily moderate- to vigorous-intensity physical activity (MVPA)) measured subjectively (5-47%) and accelerometer measured minutes of MVPA (23-200 min). Overall boys and children were more active than girls and adolescents. Different measurement methods (subjective n = 12, objective n = 18) and reported outcome variables (n = 17) were used in the included articles. Different accelerometer intensity thresholds used to define MVPA resulted in substantial differences in MVPA between studies conducted in the same countries when assessed objectively.
  
  
  CONCLUSIONS
  Reported levels of physical activity and prevalence of compliance to physical activity recommendations in youth showed large variation across European countries. This may reflect true variation in physical activity as well as variation in assessment methods and reported outcome variables. Standardization across Europe, of methods to assess physical activity in youth and reported outcome variables is warranted, preferably moving towards a pan-European surveillance system combining objective and self-report methods.
authors.affiliation: Department of Public Health, Faculty of Medicine and Health Sciences, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.|Physical activity, nutrition and health research unit, Department of Movement and sport Sciences, Faculty of Physical Education and Physical Therapy, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
authors.forename: Linde
authors.initials: L
authors.lastname: Van Hecke
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, EMGO+ Institute for Health and Care Research, De Boelelaan 1089a, 1081 HV, Amsterdam, The Netherlands. a.loyen@vumc.nl.
authors.forename: Anne
authors.initials: A
authors.lastname: Loyen
authors.affiliation: Department of Movement and Sports Sciences, Faculty of Medicine and Health Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium.
authors.forename: Maïté
authors.initials: M
authors.lastname: Verloigne
authors.affiliation: Department of Public and Occupational Health, VU University Medical Center, EMGO Institute for Health and Care Research, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.|Sydney School of Public Health, The Charles Perkins Centre (D17), University of Sydney, 2006, Sydney, NSW, Australia.
authors.forename: Hidde P
authors.initials: HP
authors.lastname: van der Ploeg
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, EMGO+ Institute for Health and Care Research, De Boelelaan 1089a, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Jeroen
authors.initials: J
authors.lastname: Lakerveld
authors.affiliation: Department of Epidemiology and Biostatistics, VU University Medical Center, EMGO+ Institute for Health and Care Research, De Boelelaan 1089a, 1081 HV, Amsterdam, The Netherlands.
authors.forename: Johannes
authors.initials: J
authors.lastname: Brug
authors.affiliation: Department of Movement and Sports Sciences, Faculty of Medicine and Health Sciences, Ghent University, Watersportlaan 2, 9000, Ghent, Belgium.
authors.forename: Ilse
authors.initials: I
authors.lastname: De Bourdeaudhuij
authors.affiliation: Department of Sports Medicine, Norwegian School of Sport Sciences, PO Box 4014, 0806, Ullevål Stadion, Oslo, Norway.
authors.forename: Ulf
authors.initials: U
authors.lastname: Ekelund
authors.affiliation: Centre for Physical Activity and Health Research, Department of Physical Education and Sport Sciences, University of Limerick, Limerick, Ireland.
authors.forename: Alan
authors.initials: A
authors.lastname: Donnelly
authors.affiliation: TNO Expertise Centre Lifestyle, Schipholweg 77-89, 2316 ZL, Leiden, The Netherlands.|Body@Work, EMGO+ Institute for Health and Care Research, VU University Medical Center, van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Hendriksen
authors.affiliation: Department of Public Health, Faculty of Medicine and Health Sciences, Ghent University, De Pintelaan 185, 9000, Ghent, Belgium.|Physical activity, nutrition and health research unit, Department of Movement and sport Sciences, Faculty of Physical Education and Physical Therapy, Vrije Universiteit Brussel, Pleinlaan 2, 1050, Brussels, Belgium.
authors.forename: Benedicte
authors.initials: B
authors.lastname: Deforche
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior; D002648:Child; D002652:Child Behavior; D003431:Cross-Cultural Comparison; D005006:Ethnicity; D005060:Europe; D015444:Exercise; D005260:Female; D015438:Health Behavior; D006801:Humans; D008297:Male; D011634:Public Health; D057185:Sedentary Behavior
keywords: Activity level; Assessment method; Childhood; Health behaviour; Prevalence; Youth