This in turn will stress the muscle fibers to the maximum. Furthermore, the speed is controlled by the exercise machine through the entire range of motion and this is an advantage for the general population because it eliminates the ballistic movement of the exercise and therefore eliminates the danger of overexposed joints or risks of muscle strains. The DISADVANTAGE is the same as all other machines: it doesn't have the natural feel of using free weights. Plus, the controlled speed adds an unnatural feel. For athletes in sports training (whose sports movements are usually ballistic) this technology may have limited usefulness. For bodybuilding, the technology can be useful for changing things up every now and then and locking muscles through a plateau by overloading them (since the devices put the muscles under such a high level of stress). STATIC RESISTANCE DEVICES This is a type of training in which you contract your muscles but without movement