The prevalence of sedentary behavior and physical activity in leisure time: A study of Scottish adolescents using ecological momentary assessment

Objective. To report time and prevalence of leisure time sedentary and active behaviors in adolescents. Method. Cross-sectional, stratified, random sample from schools in 14 districts in Scotland, 2002-03, using ecological momentary assessment (n=385 boys, 606 girls: mean age 14.1 years: range 12.6-16.7 years). This is a method of capturing current behavioral episodes. We used 15 min time intervals. Results. Television viewing occupied the most leisure time. The five most time consuming sedentary activities occupied 228 min per weekday and 396 min per weekend day for boys, and 244 min per weekday and 400 min per weekend day for girls. with TV occupying one-third to one-half of this time. In contrast, 62 min was occupied by active transport and sports/exercise per weekday and 91 min per weekend day for boys, with 55 min per weekday and 47 min per weekend day for girls. A minority watched more than 4 h of TV per day, with more at weekends. Other main sedentary behaviors for boys were homework, playing computer/video games, and motorised transport and, for girls, homework, motorised transport, and sitting and talking. Conclusion. Scottish adolescents engage in a variety of sedentary and active behaviors. Research into sedentary behavior must assess multiple behaviors and not rely solely on TV viewing. (C) 2008 Elsevier Inc. All rights reserved.