Promoting physical activity for children's health: rationale and strategies.

While the benefits of physical activity for youth are many, the specific role of exercise in promoting physical health in youth relates to the salutary effects of regular activity on life-long pathological processes that become clinically apparent in the adult years. While this concept is not easily tested by direct studies, a number of indirect pieces of information firmly support this rationale for promoting exercise habits during the paediatric years. Additional research is needed to more specifically identify the nature, frequency and duration of activity during childhood necessary for positive health outcomes. Similarly, optimal means of behavioural modification in young persons that will initiate exercise habits early in life need to be better defined.