Ancient Olympians: Weighted Down to Win
for National Geographic News
|November 14, 2002|
For an Olympian athlete looking to out-jump the competition, clutching a hefty mass of lead or stone in each hand sounds like the last thing that would help. But that's exactly what ancient Greek long-jumpers did. Vases from the period show athletes holding pairs of matching weights, which the Greeks called "halteres."
Now, a pair of biomechanics researchers has offered a scientific explanation of how this counterintuitive tactic worked.
They solved the mystery with the aid of computers and high-tech equipment designed to measure force and motion, but they also readily acknowledged the contributions of a distant intellectual predecessor: "Amazingly enough, Aristotle was very close to the solution," said Italian researcher Alberto Minetti, a professor of sports science at Manchester Metropolitan University in Alsager, England.
Using a computer code written to model the mechanics of jumping, Minetti and graduate student Luca Ardigó studied how halteres could affect the leaps of standing long-jumpers. The researchers then asked volunteers to put the virtual experiments to the test by jumping from a standstill either unencumbered or holding weights of varying masses.
In both experiments, Minetti said, "we found three kilograms [6.6 pounds] was the optimum mass" to carry in each hand.
The ancient athletes apparently determined this for themselves, presumably from trial and error.
"This is the average mass of the halteres that [archaeologists] have found," Minetti noted.
Actual specimens vary from 2.4 to 9.9 pounds (1.1 to 4.5 kilograms) each. Optimal weight would have varied slightly depending on an individual jumper's height and arm length.
Above the Competition
Using halteres enabled standing long-jumpers to exploit several properties of physics, the researchers determined.
First, by swinging their artificially heavy arms forward and above their heads just before launching themselves into the air, jumpers could shift their weight both upward, as though jumping from a platform, and forwardeffectively starting in front of the starting line. These tactics depend on shifting the center of mass, the theoretical balancing point on a jumper's body.
The halteres could also help the athletes while they were mid-bound, even though the trajectory of a jumper's center of mass is determined at the instant of launch.
"When you are landing" without halteres, Minetti explained, "your center of mass is close to your lower trunk. But with the hands [and halteres] back you could put your feet more forward." That makes a difference in the long jump, because what counts is where the feet hit the ground.
Furthermore, by enabling competitors to bring their upper-body muscles into play during launch, halteres would have permitted jumpers to propel themselves off the ground with more initial forceat least enough to compensate for the extra weight they bore.
Finally, even the legs can provide more power when working against halteres. "It's much more effective to contract against a load than [to contract muscles] against no load," said Minetti. The ancient Greek philosopher Aristotle recognized this and commented on it in writing about halteres.
The combination of all these small advantages means that the hand-held weights could have contributed an additional seven inches (17 centimeters) to a natural jump of ten feet (three meters), the researchers reported in the November 14 issue of the British science journal Nature.
Best Feet Forward
Long-jump competitors are thought to have first exploited the quirks of physics to boost their performance in 708 B.C., during the 18th Olympic Games, said Minetti. Those Games were the first to include the standing long jump as one of five events in the pentathlon.
Some historians have speculated that airborne athletes may have actually thrown their halteres backward before they themselves hit the ground. "If they did," Minetti said, "flight could be prolonged even more" than his calculations suggest.
He is wary, however, of assuming that this technique was practiced. While lead halteres would have been sturdy enough to sustain a hard impact, he said, stone weights might have broken under the force. Given the careful craftsmanship that went into carving some stone halteres, athletes probably would have been loath to risk breaking them, Minetti said.
Even if halteres were permitted today, he noted, they wouldn't necessarily propel long-jumpers farther. The long-jump event in modern Olympic Games involves a running start, which makes the biomechanics different than those Minetti and Ardigó so carefully modeled.
Should the standing long jumphalteres and allbe reintroduced into the Olympics? Said Minetti: "I would like it to be, in a way."
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