While the gym’s equipment has been woefully inadequate for his strength lately, he still goes there for some reason.
The reason being Big Mac, whose mighty body was quite light in comparison with even a single arm of Featherweight. Such thick arms, Big Mac couldn’t even put his arms around them. Two ponies, perhaps could try to join hoofs around one, barely.
But Mac was content with trying on his own. For curiosity’s sake. To feel the hard muscles against his body, moving him as if he were nothing with every twitch and bulging from Featherweight’s slightest moves.