A prospective study of sedentary behavior in a large cohort of youth

Med Sci Sports Exerc. 2012 Jun;44(6):1081-7. doi: 10.1249/MSS.0b013e3182446c65.

Abstract

Purpose: The study's purpose was to describe longitudinal patterns of objectively measured sedentary behavior from age 12 to 16.

Methods: Children participating in the Avon Longitudinal Study of Parents and Children wore accelerometers for 1 wk at ages 12, 14, and 16. Participants included boys (n = 2591) and girls (n = 2845) living in a single geographic location in the United Kingdom (Bristol). Total minutes per day spent in sedentary behavior and time spent in blocks of sedentary behavior lasting 10-19, 20-29, and ≥ 30 min are described. Growth curve models were used to determine the rate of change in sedentary behavior from age 12 to 16.

Results: At age 12, the boys and girls, on average, were sedentary for 418.0 ± 67.7 and 436.6 ± 64.0 min·d(-1), respectively, and sedentary behavior increased over time to 468.0 ± 74.3 and 495.6 ± 68.9 min·d(-1) at age 14 and to 510.4 ± 76.6 and 525.4 ± 67.4 min·d(-1) at age 16. Growth curve analyses found that total sedentary behavior increased at a rate of 19.5 ± 0.7 and 22.8 ± 0.7 min·d(-1)·yr for the boys and girls, respectively. The absolute mean increase in total sedentary behavior (+92.4 and +88.8 min·d(-1) for the boys and girls, respectively) closely matched the mean decrease in light physical activity (-82.2 and -82.9 min·d(-1) for the boys and girls, respectively) from age 12 to 16. Time spent in continuous sedentary behavior lasting ≥ 30 min increased by 121% from age 12 to 16.

Conclusions: Sedentary behavior increased with age, at the expense of light physical activity. The increase in sedentary behavior lasting ≥ 30 min in duration contributed greatly to the increase in total sedentary behavior.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Age Factors
  • Anthropometry
  • Child
  • Child Development / physiology*
  • England
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Monitoring, Ambulatory
  • Prospective Studies
  • Sedentary Behavior*
  • Time Factors