joe's left elbow couldn't straighten out, he injured it when he was a kid, which is a reason why he relied on the left hook. Boxers then and now probably would not do well in athletic competitions like that, most fighters haven't been encouraged to do a lot of those different things, especially then. You could see joe had probably never been in the water in his fucking life, or rode a bicycle, it's unrealistic to expect him to be able to do it on the spot as well as these other guys, put them in a ring with joe and see who's more athletic, strong and who gets exhausted first.