title: Trends in Physical Activity and Sedentary Behaviors of United States Youth.
abstract: BACKGROUND
  Increases in childhood and adolescent obesity are a growing concern in the United States (U.S.), and in most countries throughout the world. Declines in physical activity are often postulated to have contributed to the rise in obesity rates during the past 40 years.
  
  
  METHODS
  We searched for studies of trends in physical activity and sedentary behaviors of U.S. youth, using nontraditional data sources. Literature searches were conducted for active commuting, physical education, high-school sports, and outdoor play. In addition, trends in sedentary behaviors were examined.
  
  
  RESULTS
  Data from the Youth Risk Behavior Surveillance System (YRBSS) and other national surveys, as well as longitudinal studies in the transportation, education, electronic media, and recreation sectors showed evidence of changes in several indicators. Active commuting, high school physical education, and outdoor play (in 3- to 12-year-olds) declined over time, while sports participation in high school girls increased from 1971 to 2012. In addition, electronic entertainment and computer use increased during the first decade of the 21st century.
  
  
  CONCLUSIONS
  Technological and societal changes have impacted the types of physical activities performed by U.S. youth. These data are helpful in understanding the factors associated with the rise in obesity, and in proposing potential solutions.
authors.affiliation: Dept of Kinesiology, Recreation, and Sport Studies, University of Tennessee, Knoxville, TN.
authors.forename: David R
authors.initials: DR
authors.lastname: Bassett
authors.forename: Dinesh
authors.initials: D
authors.lastname: John
authors.forename: Scott A
authors.initials: SA
authors.lastname: Conger
authors.forename: Eugene C
authors.initials: EC
authors.lastname: Fitzhugh
authors.forename: Dawn P
authors.initials: DP
authors.lastname: Coe
mesh_terms: D000293:Adolescent; D000294:Adolescent Behavior / Q000502:physiology*; D002648:Child; D005260:Female; D015438:Health Behavior; D006801:Humans; D007899:Leisure Activities; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D063766:Pediatric Obesity / Q000453:epidemiology*; D010806:Physical Education and Training / Q000639:trends*; D012309:Risk-Taking; D012574:Schools; D057185:Sedentary Behavior; D013177:Sports / Q000502:physiology; D014481:United States / Q000453:epidemiology