Die Rolle von Sport und Bewegung für die körperliche und psychische Gesundheit.

Physical activity plays an important role in children’s growth and development. Understanding why a child is active or inactive is, therefore, essential for prevention of and intervention in childhood obesity. This narrative review provides an up-to-date summary of the literature pertaining to biological, psychosocial and environmental factors affecting young children’s acquisition of physical activity behaviour. Physical activity-related traits are characterized by familial aggregation and influenced by genetic factors. Nevertheless, the genetic contribution to physical activity shows increasing expression with age, supporting the need for interventions in early childhood. In addition to genetic factors, a range of psychosocial and environmental factors that are associated with physical activity in children have been identified: boys are more active than girls, and children with active parents tend to be more active. Overall physical activity support provided by parents predicts children’s organized physical activity. Perceived road safety and threat posed by strangers are major causes of parental anxiety in relation to their children’s safety in the neighbourhood. Programmes designed to increase physical activity should promote the importance of physical activity to parents. In addition, improving perceived safety may help to ease parental restriction of their children's active transport and physical activity.