Data for: Validity of items assessing self-reported number of breaks in sitting time among children and adolescents

This dataset contains: - Demographical information: Education, year and month born, sex - Data on self-reported number of breaks per hour from sitting taken school, while watching TV and during other screen time activities in children and adolescents. - activPAL number of valid weekdays - activPAL average weekday sit-to-stand transitions (frequency) at school, after school and in the evening - activPAL average weekday wear time (minutes) at school, after school and in the evening