I used to do a lot of boxing and I did find it to be pretty catabolic. I guess if you do it for a short period of time you shouldn't have that much of a problem, but when I boxed it was rounds and rounds. But IMO I would think that if you do it for say 20-35mins at a reasonable pace it shouldn't be much more catabolic than other forms of cardio. Just watch your heart rate and make sure it doesn't get to high. Also make sure you get plenty of rest inbetween boxing sessions. I would advice at the most everyother day.

Pain