Assessment of Physical Activity among Children and Adolescents: A Review and Synthesis

Abstract Accurate assessment of physical activity in children and adolescents is a challenge. At least six categories of techniques have been used to assess physical activity among children and adolescents, including self-report, electronic or mechanical monitoring, direct observation, indirect calorimetry, doubly labeled water, and direct calorimetry. Each type of technique carries certain strengths and weaknesses. The purpose of this paper is to review and synthesize available evidence on reliability and validity of physical activity assessment techniques used for children and adolescents. More than 50 papers published between 1971 and 1997 were reviewed for reliability and validity information with children and adolescents ranging in age from 4 to 17 years. In general, the aggregate of the published data suggests a moderate to high test–retest and interinstrument reliability of physical activity assessment although these findings are less consistent among younger children and when the time period between observations in a test–retest assessment was longer than a few days. Results of validity studies are variable, largely due to the use of different validation standards and study designs. A lack of gender and ethnic comparisons was evident in the review. The available data suggest low to moderate validity for self-report and monitoring measures of physical activity. The choice for use of a particular method of activity assessment among children and adolescents depends largely on the design of the study and the age of the participants. Greater effort toward developing a consistent standard of measure is necessary to make future advancements in improving the accuracy of physical activity assessment among children and adolescents. Moreover, information relevant to girls and ethnic minority children is urgently needed.