SRP
Cathlete
I like kickboxing, but it never seems to get my heart rate up where I want it. I was thinking that an interval routine might work, based on Cathe's typical Imax interval set up: focus on the kicking combos (instead of the punching combos) for the kickboxing, and make the interval blasts as plyometric moves: tuck jumps, power lunges, air jacks.... you know! Then at the end, for an additional calorie-burning bonus, tack on some nifty punching combos.