Parents should probably be more concerned about not allowing their diabetic teens to play sports than allowing them to play. Physical activity is not only an essential component of controlling diabetes-it also improves your child's current and long-term health.

Be Sure Your Teen is Ready and Prepared Before giving your teen the go-ahead to play sports, schedule a doctor's visit for a physical to determine diet, insulin needs and exercise readiness. Your physician may advise your teen to start slowly and work up to more strenuous levels of exercise, especially if your child's overweight and out of shape. Make sure your teen follows your physician's recommendations to the letter.

Tell coaches and sports directors about your teen's diabetes and how to handle an emergency. Make sure your child brings a supply kit that includes a diabetic testing kit, written health plan, emergency contact information, insulin and healthy snacks to workouts and games.
Diabetic Teens and Sports - ktla.com