title: Locations of Physical Activity as Assessed by GPS in Young Adolescents.
abstract: OBJECTIVE
  To compare adolescents' physical activity at home, near home, at school, near school, and at other locations.
  
  
  METHODS
  Adolescents (N = 549) were ages 12 to 16 years (49.9% girls, 31.3% nonwhite or Hispanic) from 447 census block groups in 2 US regions. Accelerometers and Global Positioning System devices assessed minutes of and proportion of time spent in moderate to vigorous physical activity (MVPA) in each of the 5 locations. Mixed-effects regression compared MVPA across locations and demographic factors.
  
  
  RESULTS
  Forty-two percent of adolescents' overall MVPA occurred at school, 18.7% at home, 18.3% in other (nonhome, nonschool) locations, and 20.6% near home or school. Youth had 10 more minutes (30% more) of overall MVPA on school days than on nonschool days. However, the percentage of location time spent in MVPA was lowest at school (4.8% on school days) and highest near home and near school (9.5%-10.4%). Girls had 2.6 to 5.5 fewer minutes per day of MVPA than boys in all locations except near school.
  
  
  CONCLUSIONS
  Although a majority of adolescents' physical activity occurred at school, the low proportion of active time relative to the large amount of time spent at school suggests potential for increasing school-based activity. Increasing time spent in the neighborhood appears promising for increasing overall physical activity, because a high proportion of neighborhood time was active. Increasing youth physical activity to support metabolic health requires strategies for increasing use of physical activity-supportive locations (eg, neighborhoods) and environmental and program improvements in unsupportive locations (eg, schools, homes).
authors.affiliation: Center for Children's Healthy Lifestyles and Nutrition, Children's Mercy Hospital, Kansas City, Missouri; jacarlson@cmh.edu.
authors.forename: Jordan A
authors.initials: JA
authors.lastname: Carlson
authors.affiliation: Department of Sports Science and Clinical Biomechanics, University of Southern Denmark, Odense, Denmark;
authors.forename: Jasper
authors.initials: J
authors.lastname: Schipperijn
authors.affiliation: Department of Family Medicine and Public Health, University of California San Diego, San Diego, California;
authors.forename: Jacqueline
authors.initials: J
authors.lastname: Kerr
authors.affiliation: Department of Pediatrics, University of Washington & Children's Hospital and Regional Medical Center, Seattle, Washington;
authors.forename: Brian E
authors.initials: BE
authors.lastname: Saelens
authors.affiliation: Department of Family Medicine and Public Health, University of California San Diego, San Diego, California;
authors.forename: Loki
authors.initials: L
authors.lastname: Natarajan
authors.affiliation: School of Community and Regional Planning, University of British Columbia, Vancouver, British Columbia, Canada;
authors.forename: Lawrence D
authors.initials: LD
authors.lastname: Frank
authors.affiliation: Perelman School of Medicine and School of Nursing, University of Pennsylvania, Philadelphia, Pennsylvania; and.
authors.forename: Karen
authors.initials: K
authors.lastname: Glanz
authors.affiliation: Department of Family Medicine and Public Health, University of California San Diego, San Diego, California;
authors.forename: Terry L
authors.initials: TL
authors.lastname: Conway
authors.affiliation: Urban Design 4 Health, Rochester, New York.
authors.forename: Jim E
authors.initials: JE
authors.lastname: Chapman
authors.affiliation: Department of Family Medicine and Public Health, University of California San Diego, San Diego, California;
authors.forename: Kelli L
authors.initials: KL
authors.lastname: Cain
authors.affiliation: Department of Family Medicine and Public Health, University of California San Diego, San Diego, California;
authors.forename: James F
authors.initials: JF
authors.lastname: Sallis
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D040362:Geographic Information Systems; D006801:Humans; D008297:Male; D009043:Motor Activity; D012111:Residence Characteristics; D012574:Schools; D013997:Time Factors