The difficulty would come not from the weight of the cats, but the wrangling
And now Iβve got a mental picture of all the cats hanging off the barbell like that kitten in the βhang in thereβ poster. Plus a random couple of them balancing on top of it, for good measure π
Each cat should be in a sock with their head poking out. There can be a handle to attach each cat sock onto the barbell. They will still wiggle a little but there isn't much they can do.