title: Physical activity and lung function in adolescents: the 1993 Pelotas (Brazil) birth cohort study.
abstract: OBJECTIVE
  To evaluate the association between physical activity changes in those aged 11 to 15 years and lung function at age 15 years.
  
  
  METHODS
  The original cohort comprised 5,249 hospital-born children during the calendar year of 1993 in Pelotas, Brazil. In 2004-2005 and 2008-2009, all cohort members were sought for follow-up visits. Self-reported physical activity was measured at ages 11 and 15 years. At the 2008-2009 visit, when participants were 15 years old, spirometry was performed. Linear regression was used, and all analyses were stratified by sex.
  
  
  RESULTS
  Of the 5,249 original members of the cohort, 4,325 were located at 15 years of age, and spirometry was performed on 4,010 members. Forced expiratory volume in 1 second was not associated with physical activity. In girls, those who were active in leisure time in both periods have better percent-predicted forced vital capacity (β = 3.573 [95% confidence interval {CI}: 1.015, 6.130]) and forced expiratory volume in the 6 seconds (β = .095 [95% CI: .021, .168]) than those who were inactive in the two periods. Also in girls, those who became active at 15 years of age had higher peak expiratory flow than those who were inactive at 11 and 15 years of age. In boys, only those who became inactive in leisure time had worse peak expiratory flow (β = -.180 [95% CI: -.339, -.021]) than boys who were inactive at ages 11 and 15 years.
  
  
  CONCLUSIONS
  Self-reported leisure-time physical activity was associated with better effort-dependent lung function parameters, particularly among girls.
authors.affiliation: Postgraduate Program in Epidemiology, Federal University of Pelotas, Pelotas, Brazil. anamene@terra.com.br
authors.forename: Ana M B
authors.initials: AM
authors.lastname: Menezes
authors.forename: Fernando César
authors.initials: FC
authors.lastname: Wehrmeister
authors.forename: Ludmila Correa
authors.initials: LC
authors.lastname: Muniz
authors.forename: Rogelio
authors.initials: R
authors.lastname: Perez-Padilla
authors.forename: Ricardo B
authors.initials: RB
authors.lastname: Noal
authors.forename: Marcelo C
authors.initials: MC
authors.lastname: Silva
authors.forename: Helen
authors.initials: H
authors.lastname: Gonçalves
authors.forename: Pedro C
authors.initials: PC
authors.lastname: Hallal
mesh_terms: D000293:Adolescent; D001938:Brazil / Q000453:epidemiology; D002648:Child; D015331:Cohort Studies; D015444:Exercise; D005260:Female; D006801:Humans; D007899:Leisure Activities; D008168:Lung / Q000502:physiology*; D008297:Male; D012044:Regression Analysis; D012129:Respiratory Function Tests; D057185:Sedentary Behavior; D012737:Sex Factors; D013147:Spirometry