title: Changes in objectively measured physical activity in adolescents with Down syndrome: the UP&DOWN longitudinal study.
abstract: It is a priority to understand that physical activity behaviour over time is a priority in Down syndrome population in order to design and promote succesfull interventions to maintain or increase levels of physical activity. We aimed to study 1 and 2-year changes in objectively measured physical activity among a relatively large sample of adolescents with Down syndrome.
  
  
  
  This study comprised a total of 99 adolescents with Down syndrome (38 girls) aged from 11 to 20 years old at baseline. Participants with valid accelerometer data at baseline and at least one of the follow-up visits were included in the analysis.
  
  
  
  Overall, levels of physical activity observed in adolescents with Down syndrome declined from baseline to follow-ups, but these changes were not significant (all P > 0.05). Moderate-to-moderately high tracking of physical activity was observed in adolescents with Down syndrome (all P < 0.001). Youths who met physical activity guidelines at baseline demonstrated a greater decline in physical activity in 1 and 2-year changes (P < 0.05), although they were also more likely to meet physical activity guidelines at 1 and 2-year follow-ups (P < 0.05).
  
  
  
  Adolescents with Down syndrome do not change their levels of physical activity at 2-year follow-ups, but those who met physical activity guidelines presented stronger declines in physical activity over time.
authors.affiliation: Ciencias de la Educación, Universidad Central de Chile, Santiago, Chile.|Department of Physical Education, Sports and Human Movement, Autonomous University of Madrid, Madrid, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Izquierdo-Gomez
authors.affiliation: Department of Physical Education, Sports and Human Movement, Autonomous University of Madrid, Madrid, Spain.
authors.forename: D
authors.initials: D
authors.lastname: Martinez-Gómez
authors.affiliation: Department of Physical Education, Sports and Human Movement, Autonomous University of Madrid, Madrid, Spain.|PROFITH "PROmotingFITness and Health through physical activity" research group, Department of Physical Education and Sport, Faculty of Sport Sciences, University of Granada, Granada, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Esteban-Cornejo
authors.affiliation: Posgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil.
authors.forename: P C
authors.initials: PC
authors.lastname: Hallal
authors.affiliation: Department of Physical Education, Sports and Human Movement, Autonomous University of Madrid, Madrid, Spain.
authors.forename: L
authors.initials: L
authors.lastname: García-Cervantes
authors.affiliation: Department of Physical Education, Sports and Human Movement, Autonomous University of Madrid, Madrid, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Villagra
authors.affiliation: Department of Physical Education, Sports and Human Movement, Autonomous University of Madrid, Madrid, Spain.
authors.forename: O L
authors.initials: OL
authors.lastname: Veiga
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004314:Down Syndrome / Q000503:physiopathology*; D015444:Exercise / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D055815:Young Adult
keywords: adolescents; intellectual disability; physical activity; prospective study