Little kids yes. However as a teen had someone explained to me how the mind plays tricks on you and that mental health plays a huge role in how you feel physically, I may not have had such a rocky start.
We do not need to tell them about depression anxiety or ptsd.
Simply tell them that when you feel angry frustrated or upset, having proper coping mechanisms like working out, can be the difference between a mental struggle that brings you down and a hurdle that is simply in your way and needs to be moved or jumped over.
You are correct, why the fuck would you teach a six year old, that depression and anxiety exist? WTAF