Age and gender differences in objectively measured physical activity in youth

Med Sci Sports Exerc. 2002 Feb;34(2):350-5. doi: 10.1097/00005768-200202000-00025.


Purpose: The purpose of this study was to evaluate age and gender differences in objectively measured physical activity (PA) in a population-based sample of students in grades 1-12.

Methods: Participants (185 male, 190 female) wore a CSA 7164 accelerometer for 7 consecutive days. To examine age-related trends, students were grouped as follows: grades 1-3 (N = 90), grades 4-6 (N = 91), grades 7-9 (N = 96), and grades 10-12 (N = 92). Bouts of PA and minutes spent in moderate-to-vigorous PA (MVPA) and vigorous PA (VPA) were examined.

Results: Daily MVPA and VPA exhibited a significant inverse relationship with grade level, with the largest differences occurring between grades 1-3 and 4-6. Boys were more active than girls; however, for overall PA, the magnitudes of the gender differences were modest. Participation in continuous 20-min bouts of PA was low to nonexistent.

Conclusion: Our results support the notion that PA declines rapidly during childhood and adolescence and that accelerometers are feasible alternatives to self-report methods in moderately sized population-level surveillance studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Activities of Daily Living*
  • Adolescent
  • Age Distribution
  • Child
  • Exercise / physiology*
  • Female
  • Humans
  • Life Style
  • Male
  • Massachusetts / epidemiology
  • Monitoring, Physiologic / instrumentation
  • Monitoring, Physiologic / methods*
  • Schools
  • Sex Distribution
  • Sports / statistics & numerical data
  • Students / statistics & numerical data*