There are two parts to the science of anaerobic high intensity training (HIT) we need to know. First, we need to know the essential physiological factors and secondly we need to know what training equipment can accommodate them.
The obvious question is. Exactly what needs to take place during high intensity training (HIT) physiologically ? Well, here are the answers. The exercise “effort” must be maximal, it must be an all out sprint. This is essential in order to engage the fast twitch muscle fibers at the Maximum Power Level in order to exhaust the ATP-PC System in the first 11 to 13 seconds of the workout. Then, the “full sprint effort” must continue to exhaust the Glycolytic System, creating a serious oxygen debt while accumulating huge amounts of lactic acid, which can not be removed quickly enough by the overwhelmed cardiovascular system. At this point, in panic, signals go to the brain that there is some serious work going on for which more muscle is essential. In response the pituitary gland orders human growth hormone production, which eventually will be distributed to all parts of the body. The greater the lactic acid concentration the greater the training effect. In fact, occluding blood flow to the muscles during this intense workout “effort” would further increase the lactic acid buildup for even a further improvement in the training effect.
Also, it is essential that the high intensity training involves a sufficiently large fast twitch muscle fiber mass, in order to challenge the cardiovascular system. To remove the accumulated lactic acid and deliver glucose and oxygen, the cardiovascular system works at full capacity. In this desirable situation, just described, there is a maximal training effect for the cardiovascular system as well as the participating muscular system.
However, in the event the participating muscle mass is too small, the training effect becomes local. As it turns out, for most persons the muscle mass of the legs, with large muscles, like Gluteus Maximus (gluts), is ideal for reaching the optimum training effect with high intensity training (HIT).