As the gym has extremely limited seating for parents, please keep in mind that the handful of chairs that line the one available wall are to be claimed by people who will actually use them. Simply stated, they are for the parents.
Note that a one-year-old does not need their own chair. Kudos to you parents with multiple small children for taking your older child to gymnastics class and juggling the other one (or two) on the sidelines.
But be aware that your toddler who spends the class period wandering the gym and jumping on equipment that shouldn't be touched anyway is not using the chair you saved for them. When they do spend time near you, it's on the floor munching fruit snacks, driving toy cars across pads, playing with their dolly, or possibly hanging out on your lap. They're never on the chair.
Furthermore, when a parent who is at least ten years your senior (although, thanks to chipmunk cheeks might not look it) comes looking for a chair to sit on and there is only one left, it behooves you to let that parent have the #*@&^@ chair.
Do not claim the chair for your young offspring. Do not point at your diapered toddler, who is swinging like a monkey off a bar ten feet away, and say, "Sorry. That chair is my son's/daughter's," and make the older parent sit on the concrete floor and get joint pain.
To the grandmother who takes her grandchildren to class, you of all people should know better. Those in polite society regularly give their seats to you, but you seem to think that the same courtesy should not be extended to others.
Your grandkid, cute though he may be, really does not need a chair to himself. Note that he refuses to sit in it and then spends the hour running around the gym like a banshee. When he calms down, he climbs not onto the chair that you thoughtfully reserved for him (and that you refused to let a mother use), but he climbs onto your lap.
He doesn't even touch the chair you reserved for your beloved posterity, an act that made a grown woman (who could be a grandmother in ten years herself) sit on the hard, cold floor.
In short, chairs in the gym should be reserved for those who can speak in complete sentences, can cut their own food, and who don't have a diaper to cushion their behinds from the concrete.
Thank you for your cooperation.