Hellhound is a High Intensity Interval Training (HIIT) workout with a strong aerobic component. High Knees is the perfect exercise for developing speed, endurance and better running ability. When knees are brought up to waist height during execution the load on the muscles is equal to that of running one mile, for every full minute. The jump knee tuck then uses fascial dynamics to strengthen the entire body, so it develops explosive power. Use this as a build-up exercise, even if you are a beginner it allows you to start at Level I and then work to Level III, in time.