Middle-school children's understanding of physical activity: "if you're moving, you're doing physical activity".

This qualitative descriptive study explored the understanding of physical activity from the perspectives of middle-school children (n = 12; ages 11-15 years) who participated in 15 collaborative exploratory meetings (approximately 1.5 hours/meeting) that were audiorecorded. Content analysis was completed; a pediatric nurse specialist and the participating children validated the findings. The children understood physical activity concretely, considering everything they did as physical activity based on their primary criterion of body movement. The children adeptly recalled activities and activity time duration, but struggled with categorizing the intensity of their activities. Domains of activity included home and school; social activities crossed both arenas. The study contributes to our knowledge of children's understanding of physical activity, highlighting the concreteness of the children's thinking, including their perspectives on evidence and conclusions based on their notions of evidence. Implications for nursing are discussed.