In briefChronic disease afflicts several million children in the United States, many of whom face the additional burden of having their physical activities unnecessarily restricted. Yet sports and exercise can alleviate symptoms as well as improve a child's psychosocial development and quality of life. Physicians should consider prescribing exercise programs for children with cystic fibrosis, congenital heart disease, juvenile rheumatoid arthritis, and asthma. They should also strongly advocate these children's right to engage in whatever levels of physical activity will allow them to reach their potential.