Corresponding Author: Joan R. Griffith, MD, Harvard Medical School, 164 Longwood Avenue, Room 318, Boston, MA 02215, USA (Tel: 617-432-2278; Fax: 617-432-3834; Email: joanrgriffith@earthlink.net)

Background: Parents' physical activity was reported to influence children's physical activity. We hypothesized that parents of 10- to 14-year-old children could influence their children's level of physical activity in ways other than providing logistical support.

Methods: Clinical observational study was conducted in a General Clinical Research Center. Normal weight (body mass index [BMI] ≤85th percentile) and at-risk of overweight (BMI >85th percentile) children aged 10 to 14 years were recruited. Sports and leisure indices were derived from the results of Baecke physical activity questionnaires administered to parent-child dyads. Children's habitual activity was determined by a 7-day pedometer log.

Results: Of 109 subjects enrolled, 48% were normal weight and 52% were at-risk of overweight. A significantly higher proportion of normal weight children (67%) versus at-risk of overweight children (49%; P=0.02, adjusted intrafamily correlation) reported patterning their physical activity after that of an adult. The mother's physical activity was more beneficial than the father's in influencing children to begin and continue physical activity.

Conclusions: The influence of parents (predominantly mothers) on their children's physical activity extends beyond enrolling children in activities and providing them with transportation to and from those activities. These findings suggest that primary prevention and intervention strategies for those at-risk of overweight children should be directed at increasing not only children's physical activity but also that of their parents, especially mothers.

Key words: exercise; at-risk of overweight; pediatric; physical activity

World J Pediatr 2007;3(4):265-270