multiple raters

Physical activity, especially unorganized activity, is an effective way to decrease obesity in children (Atlantis et al, 2006; Tremblay & Willms, 2003) . Also given that physical activity in adolescence is linked to adult physical activity (Tammelin, Nayha, Hills, & Jarvelin, 2003) and that physical activity in adulthood is associated with physical and mental health (McAuley, Blissmer, Katula, Duncan, & Mihalko, 2000) , encouraging physical activity in early childhood can be considered a health-promotion activity. Although many children (girls and boys) continue to participate in unorganized activity throughout childhood and adolescence, the declines noted in girls suggest that their participation, in particular, should be targeted. In addition, boys whose parents have less than a high school education or those in single-parent families were less likely to follow tiffany necklaces sale regular pattern of participation, also suggesting that targeted promotion to these groups may be beneficial.Strengths and Limitations

Several limitations of the current study tiffany necklaces consideration. First, physical activity was measured by a single question which reflected frequency of participation only. Markers of intensity or participation duration were not available. Therefore, these findings reflect children's frequency of participation in some type of unorganized physical activity at least once per week. This level could be considered low to be associated with specific health benefits. For instance, the current Canadian Physical Activity Guidelines for Children recommend 90 min of daily physical activity participation (Health Canada and Canadian Society for Exercise Physiology, 2002). Boys' participation in unorganized physical activity did not demonstrate this expected participation pattern, which may reflect the relatively low amount of activity required to be tiffany jewellery physically active in this sUtdy. Although it might be difficult for parents and/or children to assess, future surveys could include more specific questions, such as estimating the length of time (per session) the individual participates in unorganized physical activity as well as the intensity, which could be estimated from the type of activity (e.g., playing hockey vs. walking with friends) .

Second, the PMK reported physical activity up to 9 years of age, after which the child/youth self-reported activity. To take advantage of the longitudinal design, data from multiple raters (i.e., parent and children) were necessary. It was not possible to examine the wide age range available in the NLSCY (ages 4-17 years) without combining two different reporters. In addition, the fact that parent and self-report response options were slightly different required the responses to be dichotomized to once per week or more versus less than once per week. However, both parental- and self-reports for 10- and 11-year-olds were available in Cycle 1 and were found to be significantly correlated, as others have shown (Sallis, 1993).