The pole vault is all about energy conversion. The kinetic energy built up during the vaulter's run turns into potential energy stored in the pole as the vaulter bends it nearly 90 degrees. When the pole recoils, it unleashes that energy to help propel the vaulter up and over the bar. Of these stages, Peter McGinnis, a professor of kinesiology at the State University of New York at Cortland, has found that the most important is the speed of the vaulter just before he plants his pole. The energy built up during the run accounts for almost 60 percent of the vault's height.