Tuesday, August 19, 2008

Science of Running Fast: NYT

By CHRISTOPHER CLAREY /New York Times
Published: August 18, 2008
BEIJING — More than 24 hours had passed since Usain Bolt’s redefining of the 100 meters, and Ato Boldon, the voluble Trinidadian who used to run the 100 for a good living, was still trying to comprehend what he had seen.
“It’s amazing, and I’m not sure I’ve wrapped my mind around it yet,” said Boldon, a four-time Olympic medalist turned television commentator.
Bolt, for his part, did not appear to be asking himself too many questions on Monday, comfortably negotiating the first two rounds of his next challenge: the 200 meters.
Some, including Michael Johnson, are increasingly warning that Johnson’s ethereal 12-year-old record of 19.32 seconds from the Atlanta Olympics is on borrowed time. But for now, the only world record that the aptly named Bolt, of Jamaica, holds is the 100, which he ran in 9.69 seconds on Saturday in the Bird’s Nest despite slowing to celebrate in the final quarter of the race.
He ran 9.69 with no measurable wind, which is highly unusual for an outdoor race. Those are not ideal conditions for a sprinter. Ideal conditions are closer to what Bolt had in New York in June, when he had a following wind of 1.7 meters per second while setting the record in 9.72 seconds.
The consensus is that every meter per second of following wind subtracts approximately five one-hundredths of a second from a sprinter’s time. “You put the wind he had in New York behind the 9.69 here, and O.K., now we could be down in the 9.5s except that he shut down with 20 meters to go,” Boldon said. “So now, I’m like, O.K., is that in the 9.4s? It’s mind-boggling.”
Or is it? Considering the checkered doping records of too many former 100-meter world-record holders, it is best to keep the superlatives under rein. In the last decade alone, the Americans Tim Montgomery and Justin Gatlin have been suspended and stripped of the record.
But Jean-François Toussaint, the director of the Paris-based Institute of Biomedical Research and Epidemiology in Sports, recently told the French sports daily L’Equipe that according to statistical models, 75 percent of the existing track and field world records are essentially out of reach but that the men’s 100 is among the 25 percent still in play.
Bolt, who has never failed a drug test, has arguments in his favor. He is not a suspiciously late bloomer. Instead, he is a precocious talent (the youngest male world junior champion in the 200 at age 15) who has only recently started running the 100 seriously and who, at 21, is the youngest man to break the 100 record.
More intriguing from a technical standpoint, there is the new paradigm theory, linked to Bolt’s unusual 6-foot-5 stature — three inches taller than Carl Lewis and two inches taller than Tommie Smith, the sprinters to whom he is most often compared.
Though Bolt is the tallest man to hold the record, he is not the first sprinter of his height to succeed in this era. Francis Obikwelu, the Nigerian-born runner who now represents Portugal, is also 6-5 and won the silver medal in the 100 at the 2004 Olympics.
But Bolt has now run 0.17 seconds faster than the 30-year-old Obikwelu has ever run with significantly less refined technique. So how did he manage a 9.69 with no wind on Saturday?
First, he had a fine opening phase of the race by his standards, even though he had the seventh-slowest reaction time in the eight-man field. “It takes a while when you’re that tall to actually get into the groove when you’re coming from sitting down basically,” said Donovan Bailey, the 1996 Olympic champion in the 100 and a former world-record holder. “I actually thought after 30 meters that Asafa Powell or even Walter Dix would be leading, but they weren’t. I called it all week. What’s going to end up happening if he jumps on them before 30 meters? Good night.”
Boldon thinks early pressure applied by the eventual silver medalist Richard Thompson in an adjacent lane helped Bolt push himself further. “An excellent start for him next to guys six, seven, eight inches shorter is not going to look great on tape,” Boldon said.
Boldon and Bailey see ample room for improvement in Bolt’s early phase. “He’s 21 years old and been really running 100 meters for four months,” Bailey said. “He’s raw.”
Boldon thrust his head forward and then jerked his chin upward. “His neck is arched coming out of the blocks like this,” Boldon said. “That’s a big no-no for somebody that tall.”
But both Boldon and Bailey marveled at the baseline speed Bolt displayed on Saturday from 30 to 70 meters, which is when a 100-meter runner hits his stride. “I don’t know how it’s possible to get faster in his middle 40 but he’s going to,” Bailey said laughing.
Bolt has a high knee lift for a sprinter, which Boldon said helps him generate force. But despite the physics involved, Bolt has a quicker turnover rate than would be expected of someone of his height, which means that he can finish one stride and begin another in a surprising hurry.
“A big wheel is going to turn over slower than a small wheel, and it used to be thought that was a disadvantage except now when you see this guy who has the turnover of somebody six feet,” Boldon said. “Add that to the fact that he’s probably covering three or four more inches with every stride and that he’s only taking 40 to 41 strides to finish a 100, and you cannot argue with the math.”
Boldon said he and the former 100-meter record-holder Maurice Greene, who are both 5-9, used to finish their races in 45 or 46 strides. Tyson Gay and Powell, Bolt’s top current competition, are at about 45. Lewis required between 43 and 44 at his fastest.
Boldon said Bolt was at 41 strides on Saturday but would surely have been at 40 had he not slowed toward the end. “All of a sprint’s velocity is created from point of touchdown until the foot is directly below the body,” said Dr. Ralph Mann, a biomechanist with USA Track and Field. “Bolt’s long stride means that he is creating velocity for a longer period than shorter runners.”
The French sprint coach Jacques Piasenta contends that Bolt, irrespective of his height, has “extraordinary feet” that allow him to push particularly hard and fast off the track and act as propulsers more than shock absorbers.
The rub is that Bolt stopped trying to run fast in the final 20 meters on Saturday. Bailey said he believed Bolt would have run “between 9.55 and 9.57” if he had pushed through the finish. “I’ll be conservative and say 9.59,” Boldon said.
But neither man was feeling conservative about Bolt’s future. “We don’t get style points, and that’s what’s good about the 100 meters, but he absolutely will get technically sounder,” Bailey said. “He’ll get tighter, like maybe Carl Lewis, systematically down the track.”
The last word, as usual, went to Boldon: “Swimming has their LZR suits and their deeper pools,” he said. “We have a 6-foot-5-inch guy that’s running 9.6s and beating the rest of the Olympic field by two tenths of a second. He’s our new technology.”

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