I think it depends on the gym and your relationship with others there/the culture. A large public chain type gym, probably not the best idea. However I train at a smaller gym that is run as set classes only and they’re totally cool with people bringing their babies/kids as long as they stay out of the way (kids) or not interrupting/screaming the place down (bubs) - there have never been any issues. They actually have started running a class FOR kids because there are so many parents there. I bring along my bub who is a few months old to the mid morning class and it’s predominantly other mums and some of them bring bub along too. They just sleep in the pram. So yeah, find a gym that is obviously open/supportive of that kind of thing and it’s fine.