title: Predictors of growth and decline in leisure time physical activity from adolescence to adulthood.
abstract: OBJECTIVE
  To study the predictors of change in leisure time physical activity (LTPA) from adolescence to young adulthood.
  
  
  METHODS
  A nationally representative sample of 3,251 Norwegian students between 12 and 19 years of age were initially surveyed, and follow-up surveys were conducted three times over a 13-year period. The initial response rate was 97%, and retention rates for the three follow-up sessions were 92%, 84%, and 82%, respectively. Four groups of predictors were assessed: sociodemographics, such as gender, age, parental socioeconomic status, pubertal status, and grades; previous LTPA, such as the amount of LTPA and sports club membership; athletic self-concept and depressive symptoms; and other health behaviors, such as smoking, dieting, and body mass. Autoregressive cross-lagged analyses were supplemented with latent growth-curve analyses.
  
  
  RESULTS
  Membership in a sports club and a positive athletic self-concept in adolescence predicted a high level of LTPA in adulthood, whereas smoking tobacco, high BMI, and depressive symptoms in adolescence predicted low levels of LTPA.
  
  
  CONCLUSIONS
  Engaging adolescents in organized sports and enhancing adolescents' athletic self-concept may increase the number of adults who are physically active. Preventive efforts to reduce tobacco consumption, obesity, and depression in adolescence may also contribute to an increase in adult LTPA.
authors.affiliation: Department of Psychology, Norwegian University of Science and Technology, Trondheim, Norway. lars.wichstrom@svt.ntnu.no
authors.forename: Lars
authors.initials: L
authors.lastname: Wichstrøm
authors.forename: Tilmann
authors.initials: T
authors.lastname: von Soest
authors.forename: Ingela Lundin
authors.initials: IL
authors.lastname: Kvalem
mesh_terms: D000293:Adolescent; D002648:Child; D003863:Depression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007899:Leisure Activities; D008297:Male; D009043:Motor Activity; D009664:Norway; D009765:Obesity; D012649:Self Concept; D012907:Smoking; D013177:Sports; D055815:Young Adult