Strong kids do not just appear to be so overnight. There is a lot of effort and some genes that contribute to the strong and healthy body conditions of a kid. Introducing exercise regimens that include some cardio workouts and weight lifting is not necessarily a negative thing to do, and neither will it hamper the growth of the kid in any way
As kids tend to be rather careless with their diets, especially if there is very little parental supervision, there is a definite possibility of the kid retaining a lot of unhealthy fat buildup in the body system. With an adequate exercise program is place there is a good opportunity for the kid to burn of all these negative elements in a fun way and stay healthy at the same time both mentally and physically.
Through the adequate exercise program, there is an increase in the neuromuscular activation point thus causing the large portions of negatively tagged foods to be burned out quickly and effectively.