Hey, I've been looking through this thread and congrats to you all on working so hard! That's awesome.
I box and am also PT personal trainer. One exercise I HIGHLY recommend is this the Burpee:
http://www.bodybuilding.com/fun/rossboxing2.htm
It's an intense conditioning exercise that'll burn fat like crazy, really work your heart and lungs and really conditions your entire body. In short, they kick yer ass..in a good way.
They're great to do at the end of your regular workout session or you can do a quick (but very intense) workout when you don't have alot of time. They're actually very popular in prison where they don't have access to weights and have limited outdoor time.