Someone who is both strong physically and mentally. i.e. Swole- to be muscularly strong, and Soldier- apparent mental stamina to stave of effects of calamities. Usually this term is used with the soldier emphasis not on a military sense, but an urban street sense (ghetto soldier). This is where the slang term 'swole' comes into play.
"Damn, did you see Mike V. fight those three assholes at the same time?"
"Yea, and look he's not even breathing hard, he's a fucking swoldier."
See Mike Vallely in CKY3.