Could boxing with no rest or break period in between rounds be a substitute for running? So instead of running for 3 or 4 miles you just box for an hour or two with no rest of break period would that be enough to make you conditioned to fight?
This forum isn't the right one to get any information on roadwork. Everyone round here believes roadwork only makes stamina worse or doesn't effect it at all. My personal opinion is no... not taking a break isn't a substitute for roadwork. I don't think your muscle and cardiovascular system could do constant work for 1 to 2 hours without any sort of break.
Where has anyone said this? Also, I thought you were quitting this forum to enhance your elite training?
You should mix your running. Sometimes long distance running and sometimes intervals/sprints. For amateur boxing 200-400m sprints would be better than running 10K long runs IMO.