Power ......The human body has about 640 muscles, and the trained fighter uses every one of them with every movement and every punch, even those that are ostensibly in repose. Some trainers refer to Kinetic Linking, the way mucles move in sequence to transfer energy from the feet up through the legs, torso, shoulder and arms to the fist, but it is more complex than that. Some muscles push, while others pull, similar to the way the moving parts of an engine move a piston, some moving this way, some in the opposite direction. But the human body is much more complex than an engine. Some muscles, the primary muscles, transfer energy directly up through the body to the fist, while other, secondary muscles, support the primary muscles, by pulling or pushing against them, adding power to the punch, and a third set of muscles, the tertiary muscles, pull or push against the secondary muscles, adding even more power to the punch, so that in the end the fighter is using all of his muscles at all times, one way or another. This doesn't happen overnight, of course. It takes years to sync all the muscles together, so that they all work together in a synchronized sequence, whether one is punching, blocking, slipping punches, or moving around the ring.