According to my health class activity sheet, wrestling/karate (MMA) burns more calories than any other form of exercise. The only activity close is running. I signed up for MMA three months ago at Ed Clay's MMA gym. For a beginner the classes involve a warm-up lots of squats with a guy on our back, pushups jogging around the octagon, pushups etc... After warming up we learn basic technique and drill submissions and practice takedowns etc... Doing this twice a week improved my cardio and leg strength. The real exercise is when you spar or roll with someone jiu jitsu style until one person submits it takes allot of energy to fight for that long. I have worked out for 5 years and I can say that mma is definitely helping to put me in the best shape of my life.