What makes Usain Bolt so fast?

(CBS News) NEW YORK - At the World Track and Field Championships in Moscow on Saturday, Usain Bolt qualified for the finals in the 100-meter dash Sunday -- once again jogging across the finish line and making it all look so unbelievably easy. Of course, looks can be deceiving, and scientists are now analyzing every step of the fastest man in the world, hoping to unlock the secrets of his performance.

Bolt is one of the most gifted athletes in the world. The six-time Olympic gold medalist has shattered world records in both the 100 and 200-meter races.

"I was given a gift and that's what I do," he once said.

At the University of Virginia's SPEED clinic, Max Prokopy studies what makes elite runners like Bolt so fast.

"He's been able to marry tremendous genetic advantages with a ton of practice and work ethic," said Prokopy.

Scientists who study speed say that when he races, Bolt's foot explodes off the ground with more than 1,000 pounds of force, compared to the 500 pounds of an average person.

It's like the difference between bouncing a beach ball and a superball. The beach ball stays on the ground and doesn't bounce as high. Bolt's foot is more like a superball, which hits the ground harder, and springs off faster.

But Bolt has other advantages. At 6' 5", he's taller than most of his competitors and his strides are nearly eight inches longer. When Bolt set the world record in the 100-meter dash in 2009, he took only 41 steps; his closest competitors each took 44..

"So his stride frequency is about the same as his competitors," Penn State Associate Professor Stephen Piazza said. "But his stride length is about seven percent longer and that's really what allows him to run the 100 meters as fast as he is able to."

"I want to try to run fast and also win my title and defend my title," said Bolt.

Bolt will get that chance Sunday, as he races to maintain his legacy as the "world's fastest man."