title: Temporal and environmental patterns of sedentary and active behaviors during adolescents' leisure time.
abstract: BACKGROUND
  There is great interest in young people's overweight and obesity. Few data, however, describe when sedentary and physically active behaviors are likely to occur during the day or how these behaviors are related to location.
  
  
  OBJECTIVE
  The purpose of this study was to describe sedentary and active leisure-time behaviors of adolescents across the day and setting.
  
  
  METHODS
  Adolescents (male n = 579, female n = 967; aged 13-16 years) completed time-use diaries for three weekdays and one weekend day. At 15 min intervals, participants recorded what they were doing and where they were.
  
  
  RESULTS
  TV viewing and sports/exercise peaked at different times in the day, although TV viewing was two to three times more likely to occur than sports/exercise. TV viewing was most likely to occur during the middle to late evening. The playing of computer games was low, particularly for girls. Weekend data showed TV viewing was the most reported activity throughout the day. For boys, "being in the garden" was highly predictive of engaging in sports/exercise, but this declined rapidly with age. Motorized travel to school was reported twice as often as active travel.
  
  
  CONCLUSIONS
  Momentary assessments of behavior, in conjunction with contemporaneous reports of environmental factors, describe important patterns of leisure-time active and sedentary behaviors in youth.
authors.affiliation: Loughborough University, Loughborough, UK. s.j.h.biddle@lboro.ac.uk
authors.forename: Stuart J H
authors.initials: SJ
authors.lastname: Biddle
authors.forename: Simon J
authors.initials: SJ
authors.lastname: Marshall
authors.forename: Trish
authors.initials: T
authors.lastname: Gorely
authors.forename: Noel
authors.initials: N
authors.lastname: Cameron
mesh_terms: D000293:Adolescent; D002940:Circadian Rhythm; D015444:Exercise; D005260:Female; D006306:Health Surveys; D006801:Humans; D007899:Leisure Activities; D008019:Life Style; D008297:Male; D057185:Sedentary Behavior; D012737:Sex Factors; D012931:Social Environment; D013177:Sports; D006113:United Kingdom