title: Tracking of pedometer-determined physical activity: a 10-year follow-up study from adolescence to adulthood in Sweden.
abstract: BACKGROUND
  Tracking refers to the tendency for an individual to maintain their rank within a group over time.
  
  
  OBJECTIVE
  To identify levels of pedometer determined physical activity and explore tracking over 10-year follow up period.
  
  
  METHODS
  In October of 2000, 2003, 2005, and 2010, data of physical activity as steps/day was measured with Yamax SW-200 Tokyo, Japan for 4 consecutive schooldays in 40 (19 females) Swedish individuals (mean age 12.7 in 2000).
  
  
  RESULTS
  In boys a decrease of mean step/day occurred between baseline and the 3-year (P < .001), the 5-year (P < .001) and the 10-year follow-up (P < .014). A significant moderate tracking occurred in those at baseline classified insufficient active, both over the 3- to 5-year span (rs = 0.56, P = .005) and the 0- to 10-year span (rs = 0.47, P = .05).
  
  
  CONCLUSIONS
  The significant decrease of physical activity, as steps/day, in males at early adolescent seems to level out during late adolescence and early adulthood. Further, youth classified insufficient active according to published BMI reference standards at the baseline measures showed a significant moderate tracking over the 10-year follow-up period.
authors.affiliation: School of Sport Sciences, Linnaeus University, Kalmar, Sweden and with the Dept of Nutrition and Sport Sciences, University of Gothenburg, Sweden.
authors.forename: Anders
authors.initials: A
authors.lastname: Raustorp
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Ekroth
mesh_terms: D056044:Actigraphy / Q000706:statistics & numerical data*; D000293:Adolescent; D000704:Analysis of Variance; D015992:Body Mass Index; D002648:Child; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007564:Japan; D008297:Male; D018670:Monitoring, Ambulatory / Q000379:methods*; D009043:Motor Activity; D017678:Sex Distribution; D013548:Sweden; D055815:Young Adult