I don't get any of that yet, but am sure I will when DD moves to team. I have a standard response to most advice and comments I get about things I have chosen to do as a parent. (And there have been MANY

, was planning a homebirth/used midwives instead of doctors, extended breastfeeding/child led weaning, co-sleeping, babywearing, using alternative medicine more than western medicine, using cloth diapers and most recently homeschooling.)
My response is "I don't try to convince you to do the things that I do and I certainly don't appreciate you trying to tell ME what to do." If that doesn't work and they are respectfully trying to argue with me (if they are rude, I ignore them or walk away) I tell them that I have researched both sides of the issue, the PROS and CONS, and
have chosen what is right for my family and that we will just have to agree to disagree. I have lost friends over some of my decisions. Life goes on.
I do understand the concerns about gymnastics. I have had/still have them myself. It is hard to understand unless you are in the situation and for me, still hard to totally understand. Just like many life situations. I don't go around telling people to do what I do, they better not try to tell me what to do. I really do understand their concerns though and think that most are truly concerned about the risks of competitive gymnastics. And of course there are those that just never know when to shup up. LOL.
I am always a bit of an outsider in mainstream life, so I am used to it. LOL. I have developed very good selective hearing.
I also usually will concede some point of theirs and give them reasons that I am okay with whatever that point is. Makes them think they have somehow won. LOL.