This literature review summarizes clinical recommendations for adequate physical activity and reviews recently published studies that focus on identifying common factors associated with physical activity levels among preschoolers in the United States and Canada. Currently, there is inconsistency in both the definition of and recommendations for physical activity. In addition, there is relatively little research in this area. Common factors and contexts associated with physical activity levels in preschoolers in this review included (a) child characteristics; (b) interpersonal dynamics between preschoolers and their families, childcare providers, and health care providers; (c) childcare setting; and (d) neighborhood environment
