Cracking the Long-Jump Code


Azusa, Calif.

The human race has made some tremendous advances over the last couple hundred thousand years. Stone tools. Vaccines. Pop-Tarts. But here’s something we haven’t quite mastered: how to long jump.

The long jump looks pretty simple: sprint down a runway and leap as far as you can. But the most miniscule adjustments can mean the difference between silver and gold for Olympic athetes. Now, a new device is helping them analyze their jumps in real time. WSJ’s Scott Cacciola reports.

When Bob Beamon leapt 29 feet, 2 ½ inches to set a world record at the 1968 Olympics, his performance was a total anomaly: He smashed the old record by nearly two feet. It helped that Beamon was jumping in the thin air of Mexico City with a slight wind at his back, but Beamon also benefited from a flash of biomechanical wizardry not even he could replicate.

Experts who have watched the jump on video say Beamon was somehow able to sweep his trail leg across his body at twice his normal rate as he hit the board, creating an explosive whipping action that launched him into the exosphere. Beamon never again broke 27 feet. His record stood for nearly 23 years until Mike Powell eclipsed the mark by two inches in 1991—a record that still stands.

By comparison, records in other events have crumbled like sand castles. The men’s high-jump record has been broken 18 times since 1968. The 1,500-meter record has gotten torched 11 times.

The long jump takes a combination of speed, strength and technical expertise few athletes are able to pull together. “People say, ‘It’s jumping, not rocket science,'” said Melvin Ramey, a biomechanist who works with USA Track & Field and a professor emeritus of civil and environmental engineering at the University of California, Davis. “Well, no. It actually is rocket science.”

For decades, coaches and trainers have developed tools to try to improve long-jump performance. They’ve told athletes to leap off wooden crates to mimic the sensation of soaring into the pit and scattered hula hoops on the runway to measure their steps. They’ve created exercises involving springs and resistance bands, force plates and hurdles.

Now, the U.S. Olympic Committee is pinning its hopes on a training tool developed by the same people who brought the world the M6 coupe.

As part of BMW’s USOC sponsorship efforts ahead of the London Games, engineers from the car maker have donated their time to construct a camera system that is designed to provide something jumpers have never had before: immediate quantitative feedback.

The distance of a long jump hinges on the moment when a jumper transfers his horizontal velocity (running speed on the runway) into vertical velocity as he leaps off the board. Most elite long jumpers are able to generate a vertical velocity that is about a third of their horizontal velocity—but, generally, the higher that ratio, the longer the jump.

Dan Krauss for The Wall Street JournalBryan Clay and biomechanist Melvin Ramey (right) review video of his jump.

BMW’s research involves using a special “stereo” camera outfitted with two lenses to film athletes as they jump. The camera, which BMW is developing for the purposes of lane-detection systems in its automobiles, turns video into data that is processed through an algorithm on an open-source robotics system. After a jump, the system spits out three crucial numbers on a trackside monitor: A jumper’s horizontal velocity, his vertical velocity as he left the board and his angle of flight.

On a recent weekday morning at Azusa Pacific University outside of Los Angeles, Cris Pavloff, an advanced technology engineer at BMW, tested the company’s equipment for the first time on decathlete Bryan Clay, a two-time Olympic medalist. As the system evolves, Clay said, he hopes he’ll be able to make instant changes to his technique while the memory of the jump is still fresh in mind. If his takeoff angle isn’t right, he can adjust his hips. If his vertical velocity is off target, he can shorten his stride as he approaches the long-jump board.

“You’re constantly looking for ways to get better,” said Clay, a 26-foot long jumper. “I guess you should say ‘legal’ ways to get better.”

Clay said the equipment could be particularly useful for decathletes and heptathletes who have a limited amount of time and energy to practice multiple events. Consider: Whenever Clay hits the board, he generates a force of up to 15 times his body weight, according to Phil Cheetham, a senior sport technologist for the U.S. Olympic Committee.

“Planting that foot and taking off at the correct angle is enormously stressful on the body,” he said.

Video technology has already had a major impact on the long jump. Ramey, who’s studied the sport since the late 1950s when he was an athlete at Penn State, now uses a point-and-shoot camera that records at 200 frames per second, which is seven times more powerful than most video cameras. Though long jumpers only spend about .15 seconds on the takeoff board, his camera is fast enough to capture 30 frames of that sequence alone.

Dan Krauss for The Wall Street JournalVideo of Clay’s jump

The trouble, Ramey said, is that long jumpers don’t merely want images to study. They want numbers. In the absence of those numbers, jumpers are often left to go on “feel” during training: Does one technique feel more effective than another? Do they feel as if they’re more explosive off the board when they strike their forefoot a certain way?

Ramey, who uses his own equipment from UC Davis, said he can crunch those numbers by “digitizing” his video and feeding the data into a series of equations, but it is an agonizingly slow process. “Maybe an hour or less if I really get after it,” Ramey said.

Joe Walker, the longtime track-and-field coach at the University of Mississippi, has worked with Ramey and other scientists. He said he supports these kinds of innovations, within reason.

“You can’t go science all the way,” Walker said. “It’s not like you have a little robot machine where you can say, ‘OK, you had a takeoff angle of 17 degrees that time, so I’m going to go down before your next jump and dial up 19 degrees.’ It just doesn’t work that way.”

Walker, who coaches Brittney Reese, the likely gold-medal favorite at the Olympics this summer, said one of his most trusted training tools is a towel that he hangs from a metal pole. He extends it over the pit and has his jumpers try to brush it with their foreheads as they leap off the board—a reminder that they should be jumping up instead of out.

Walker said he picked it up from watching Ralph Boston, the three-time Olympic medalist and former world record holder. He retired in 1968.

Write to Scott Cacciola at [email protected]