If they do at all say you are a marathon runner or a long distance swimmer or a long distance cyclist how would being good in these discplines help in boxing training?
Hardly any, if anything at all. Lance Armstrong found out that even cross over between long distance cycling and long distance running wasn't much when he ran the marathon of New York. His VO2Max was high enough but apart from that it's a different ballgame.
..Well you would be in better shape than most people who just go into a gym. But youd also probably be a little *****... :-D