Reliability and Validity of Physical Activity Questionnaires for Children: The Children’s Leisure Activities Study Survey (CLASS)

This study aimed to develop a reliable, valid, and feasible method for assessing physical activity among children ages 5–6 and 10–12 years. Test–retest reliability of a parental proxy questionnaire and a children’s self-report questionnaire was assessed in 280 children and parents. The criterion validity of the questionnaires was assessed using accelerometry. The proxy questionnaire provided a reliable measure of the type, frequency, and duration of children’s physical activity. Neither version of the questionnaire provided an accurate estimate of individual children’s physical activity. To assess the type, frequency, intensity, and duration of children’s activity, a combination of questionnaire and objective measures should be employed.