Caladium trains to remain quick on his feet in battle, and to not be burdened by the padding of his diapers. You may probably be wondering why he doesn't just take them off in battle then? Well, one time, he had a bit of an 'accident' while somersaulting mid-combat, thankfully it was just a training routine, but his eyes were burning for nearly an hour. And the humiliation of it all was unbearable...
While accidents do still happen mid-fights, they are thankfully contained within his diapers this time. But the added weight can be a struggle, and why he trains to keep up if needed.