As a person who uses the fitness centers, and has been to most of them on Disney property, I'm gonna say the answer is probably no. I know the YC/BC, Boardwalk, Contemporary, and Coronado Springs health clubs are all too small to even consider it. The only one in my opinion that you might check with is the Disney Institute. I know the last time I was there (the health club is still open even though the resort is closed, and I highly recommend this one, it's very nice), the Disney Institute health club did offer some kind of aquatic exercise, because they do have a small indoor pool there, but that may be the closest thing to what you're looking for. I also think that the Swan and Dolphin are just fitness equipment, although feel free to check with them in case they offer it in another place or something. I don't remember seeing aerobics at the Grand Floridian either, but again you're welcome to check, since that resort has so many specialty things that are not offered at the other resorts, you never know. Overall, I think the answer is probably no, they don't offer aerobics classes, probably just out of lack of demand, and that you would have to go offsite.
