Depends. When I first started boxing I couldnt make it three rounds and did everything I was told to do get in shape. As you gain experience and learn to relax it becomes easier. It also depends at which pace the fight is fought which is a huge factor. I could probably go in the gym and box 6-8 rounds right now at a fairly modest pace, and Im in no kind of boxing condition, but I know how to survive and stay relaxed.
