Although the benefits of regular physical activity are widely acknowledged, recent findings indicate that a growing number of youth are not as active as they should be. The impact of a sedentary lifestyle during childhood on lifelong pathological processes and associated health care costs have created a need for immediate action to manage, if not prevent, unhealthy behaviors during this vulnerable period of life. The concept of identifying children with exercise deficit disorder early in life and prescribing effective interventions to prevent the cascade of adverse health outcomes later in life is needed to raise public awareness, focus on primary prevention, and impact the collective behaviors of health care providers and public health agencies. School nurses are in a unique position to take advantage of well-child visits as an ideal opportunity to assess physical activity habits and encourage daily participation in play, recess, sports, planned exercise, and physical education.