It is now apparent that chronic diseases starts in early childhood and professionals should therefore emphasize the importance of a lifestyle of regular physical activity from childhood and during adolescence, which continues into and throughout adulthood, for the health and well-being of both individuals and populations. Programs that correspond with an active life style should be assembled in accordance with clinical and research findings, be community based and easily accessed by all and throughout the year, with specific consideration for individual needs such as function, disability, sex, and age of the participants. We have discussed this issue in this book, but you will also find chapters focused on school and adolescent health, juvenile firesetting, chronic illness, internet, teenage pregnancy and substance abuse.