When I was taking karate, I didn't mess around with weights. Well, I was a freshman in high school, living far from a gym - so I just never was introduced to them. Anyway, though, I got in pretty good shape - even without weights. Well, I was doing sit-ups and push-ups all the time - so that built me up pretty good. Well, the problem was the legs, though. You simply can't get a good enough cardio thing in karate - though the sparring does wear you out. Anyway, in college I was doing cardio along with sparring - and I wore an opponent out.