Jumpers tend to lean forward as they take off, causing their center of mass to drop. “That’s the kiss of death,” says Williams’ coach, Cliff Rovelto. Williams stays upright—a function of having terrific body control and a tremendously strong core. To maintain the latter, Williams does ab workouts three or four times a week.
At last year’s world championship in South Korea, which he won with a jump of just over 7 feet 8 inches, Williams was running 24.9 feet per second just before takeoff. That’s faster than most elite jumpers, who are clocked between 22.3 and 24.2 feet per second. “The smaller you are, the faster you can accelerate,” says John Eric Goff, professor of physics at Virginia’s Lynchburg College and author of Gold Medal Physics: The Science of Sports. Williams’ acceleration gives him an edge on the high jump’s short 50-foot track, allowing him to generate enough power to make up for his comparitively short stature.
Converting speed into a vertical leap takes tremendous strength. Williams spends a lot of time lifting weights to build fast-twitch fibers—powerful muscles that help explosiveness. Williams can lift about 15 percent more weight than most other elite high jumpers. When he jumps, “he’s applying about 350 pounds of force to the ground,” says Goff.
“Jesse has really strong, rigid ankles,” says Rovelto. “Even if his technique is a little sloppy, he’s still OK because he can generate power from his ankles.” Williams occasionally trains barefoot in the sand, which forces ankle muscles to work harder and become stronger.
Men's high jump: August 7, 1 p.m. EDT