Usain Bolt defended his 200 m title with ease and took his tally of World Championship gold medals to seven.
The Jamaican set a world leading time of 19.66 seconds at the World Atheltics in Moscow to secure his third successive world title in the event.
Usain Bolt’s compatriot Warren Weir clinched silver with a personal best 19.79 while America’s Curtis Mitchell (20.04) took bronze by a hundredth of a second.
Usain Bolt defended his 200 m title with ease and took his tally of World Championship gold medals to seven
His winning time was nearly five tenths slower than his personal best, the world record time of 19.19 he set in Berlin, and the slowest of his gold-medal wins over the distance.
But with Tyson Gay absent through suspension and his compatriot Johan Blake injured, Usain Bolt did not have to produce a vintage display to secure the result the vociferous sell-out crowd in the Luzhniki Stadium expected.
By the time the world record holder celebrates his 27th birthday on Wednesday, he could see his name alongside Americans Carl Lewis, Michael Johnson and Allyson Felix as the most decorated gold medallist in the championships’ history.
The speed of Usain Bolt’s progress to the top of that list of high achievers depends on Sunday’s 4×100 m sprint relay final.
Usain Bolt regained his 100 m world title and won a fourth individual World Championships gold with a season’s best of 9.77 seconds in Moscow.
In heavy rain, the 26-year-old Jamaican made amends for his false start in Daegu two years ago and further cemented his status as the greatest sprinter in history.
The six-time Olympic champion overtook Justin Gatlin in the final stages, forcing the American to settle for silver in 9.85.
Usain Bolt’s compatriot Nesta Carter (9.95) claimed bronze, while Britain’s James Dasaolu was eighth (10.21).
It was another convincing victory for Usain Bolt, who demonstrated his superiority by equalling the eighth-fastest time of his career in unfavourable conditions.
Such is Usain Bolt’s dominance of the event, he does not have to be at his quickest to win major championships.
Usain Bolt regained his 100 m world title and won a fourth individual World Championships gold in Moscow
Justin Gatlin, who beat Usain Bolt in Rome in June, said: “I’m getting closer, I’m very happy with my race. The last 30m I got long. In Rome I was able to… do my race, which I didn’t do tonight.
“He [Usain Bolt] has been working on his start – in Rome he had the best reaction out of everybody and he is 6ft 5in. I had to make sure I was beating him to 50 m.”
James Dasaolu, who ran 9.97 in the semi-finals earlier on Sunday, said: “I got to 50 m or 60 m but then they just started to run away from me.
“I think the semi-final took it out of me, but I made it through three rounds and I’m happy that I’m injury free and I can continue with the rest of the season.”
The sight of Usain Bolt surging past his rivals is now a familiar one, as is his fooling around at the start line – as the rain bounced off the Moscow track, he mimed holding an umbrella.
When the gun went, his reaction time of 0.163 sec was equal to that of main rival Justin Gatlin, and the pair were shoulder-to-shoulder before Usain Bolt eased away.
Perhaps the only disappointment of the evening was that the Luzhniki Stadium was not full for the championships’ blue riband event.
Those who were there, however, saved their loudest cheers for the man charged with lifting the sport after a spate of failed drug tests, the most recent concerning Trinidad and Tobago sprinter Kelly-Ann Baptiste.
But neither the rain nor doping scandals could dampen the celebrations as Usain Bolt, with flashbulbs lighting up the stadium, embarked on a jubilant lap of honor.
According to the mathematical model proposed, Usain Bolt’s time of 9.58 seconds in Berlin was achieved by reaching a speed of 12.2 metres per second, equivalent to about 27 mph.
The team calculated that Usain Bolt’s maximum power occurred when he was less than one second into the race and was only at half his maximum speed. This demonstrates the near immediate effect of drag, which is where air resistance slows moving objects.
They also discovered less than 8% of the energy his muscles produced was used for motion, with the rest absorbed by drag.
Usain Bolt’s extraordinary speed has been explained by scientists with a mathematical model
When comparing Usain Bolt’s body mass, the altitude of the track and the air temperature, they found out that his drag coefficient – which is a measure of the drag per unit area of mass – was actually less aerodynamic than that of the average man.
Jorge Hernandez of the National Autonomous University of Mexico said: “Our calculated drag coefficient highlights the outstanding ability of Bolt. He has been able to break several records despite not being as aerodynamic as a human can be.
“The enormous amount of work that Bolt developed in 2009, and the amount that was absorbed by drag, is truly extraordinary.
“It is so hard to break records nowadays, even by hundredths of a second, as the runners must act very powerfully against a tremendous force which increases massively with each bit of additional speed they are able to develop.
“This is all because of the ‘physical barrier’ imposed by the conditions on Earth. Of course, if Bolt were to run on a planet with a much less dense atmosphere, he could achieve records of fantastic proportions.
“The accurate recording of Bolt’s position and speed during the race provided a splendid opportunity for us to study the effects of drag on a sprinter.”
“If more data become available in the future, it would be interesting to see what distinguishes one athlete from another,” added Jorge Hernandez.
Usain Bolt’s time in Berlin was the biggest increase in the record since electronic timing was introduced in 1968.
John Barrow at Cambridge University who has previously analyzed how Usain Bolt could become even faster, explained that his speed came in part due his “extraordinary large stride length”, despite having such an initial slow reaction time to the starting gun.
“He has lots of fast twitch muscle fibres that can respond quickly, coupled with his fast stride is what gives him such an extraordinary fast time.”
John Barrow said Usain Bolt has lots of scope to break his record if he responded faster at the start, ran with a slightly stronger tail-wind and at a higher altitude, where there was less drag.
Usain Bolt’s Berlin record was won with a tail wind of only 0.9 m per second, which didn’t give him “the advantage of helpful wind assistance”, John Barrow added.
Cheetah robot has set a new world speed record for legged robots, running faster than Usain Bolt, who is considered the fastest human.
The headless machine, funded by the Pentagon, reached 28.3 mph (45.5 km/h) when tested on a treadmill.
Jamaican sprinter Usain Bolt’s top speed is 27.78 mph (44.7 km/h).
The project is part of efforts to develop robots for military use. One robotics expert said that it was “unfortunate” the Cheetah was made primarily “to kill people”.
It has been created by the Massachusetts robotics company Boston Dynamics and backed by the US Defense Advanced Research Projects Agency (DARPA).
Cheetah robot has set a new world speed record for legged robots, running faster than Usain Bolt
According to DARPA, the aim is to “more effectively assist war fighters across a greater range of missions”.
The Cheetah, which is powered by a hydraulic pump, broke its own record of 18 mph (29 km/h), recorded in February.
“The Cheetah had a slight advantage over Bolt as it ran on a treadmill, but most of the power Cheetah used was to swing and lift its legs fast enough, not to propel itself forward,” DARPA said in a statement.
The agency plans to test the robot in the field in 2013.
The machine’s design has been inspired by the real cheetah, the fastest land animal, which can reach speeds of 75 mph (121 km/h).
“Cheetahs happen to be beautiful examples of how natural engineering has created speed and agility across rough terrain,” said Gill Pratt, DARPA programme manager.
“Our Cheetah bot borrows ideas from nature’s design to inform stride patterns, flexing and unflexing of parts like the back, placement of limbs and stability.”
“What we gain through Cheetah and related research efforts are technological building blocks that create possibilities for a whole range of robots suited to future Department of Defense missions.”
Noel Sharkey, professor of artificial intelligence and robotics at the University of Sheffield, has mixed feelings about the development.
“It’s an incredible technical achievement, but it’s unfortunate that it’s going to be used to kill people,” he suggested.
“It’s going to be used for chasing people across the desert, I would imagine. I can’t think of many civilian applications – maybe for hunting, or farming, for rounding up sheep.
“But of course if it’s used for combat, it would be killing civilians as well as it’s not going to be able to discriminate between civilians and soldiers.”
DARPA’s press release for the Cheetah project suggested that the robots might ultimately be used in “emergency response, humanitarian assistance and other defence missions”.
To understand how fast a human can ultimately run, we need to go beyond the record books and understand how Jamaican sprinter Usain Bolt’s legs work.
In 2008, at the Beijing Olympic Games, Usain Bolt ran the 100 m in just 9.69 seconds, setting a new world record. A year later, Usain Bolt surpassed his own feat with an astonishing 9.58-second run at the 2009 Berlin World Championships. With the 2012 Olympic Games set to begin in London, the sporting world hopes Usain Bolt will overcome his recent hamstring problems and lead yet another victorious attack on the sprinting record. He is arguably the fastest man in history, but just how fast could be possibly go?
That’s a surprisingly difficult question to answer, and ploughing through the record books is of little help.
“People have played with the statistical data so much and made so many predictions. I don’t think people who work on mechanics take them very seriously,” says John Hutchinson, who studies how animals move at the Royal Veterinary College in London, UK.
The problem is that the progression of sprinting records is characterized by tortoise-like lulls and hare-like… well… sprints. People are getting faster, but in an unpredictable way. From 1991 to 2007, eight athletes chipped 0.16 seconds off the record. Bolt did the same in just over one year. Before 2008, mathematician Reza Noubary calculated that “the ultimate time for [the] 100 meter dash is 9.44 seconds.” Following Usain Bolt’s Beijing performance, he told Wired that the prediction “would probably go down a little bit”.
John Barrow from the University of Cambridge – another mathematician – has identified three ways in which Usain Bolt could improve his speed: being quicker off the mark; running with a stronger tailwind; and running at higher altitudes where thinner air would exert less drag upon him. These tricks may work, but they’re also somewhat unsatisfying. We really want to know whether flexing muscles and bending joints could send a sprinter over the finish line in 9 seconds, without relying on environmental providence.
To understand how fast a human can ultimately run, we need to go beyond the record books and understand how Jamaican sprinter Usain Bolt's legs work
To answer that, we have to look at the physics of a sprinting leg. And that means running headfirst into a wall of ignorance.
“It’s tougher to get a handle on sprinting mechanics than on feats of strength or endurance,” says Peter Weyand from Southern Methodist University, who has been studying the science of running for decades.
By comparison, Peter Weyand says that we can tweak a cyclist’s weight, position and aerodynamic shape, and predict how that will affect their performance in the Tour de France.
“We know down to 1%, or maybe even smaller, what sort of performance bumps you’ll get,” he says.
“In sprinting, it’s a black hole. You don’t have those sorts of predictive relationships.”
Our ignorance is understandable. By their nature, sprints are very short, so scientists can only make measurements in a limited window of time. On top of that, the factors that govern running speed are anything but intuitive.
Peter Weyand divides each cycle of a runner’s leg into what happens when their foot is in the air, and what happens when it’s on the ground. The former is surprisingly irrelevant. Back in 2000, Peter Weyand showed that, at top speed, every runner takes around a third of a second to pick their foot up and put it down again.
“It’s the same from Usain Bolt to Grandma,” he says.
“She can’t run as fast as him but at her top speed, she’s repositioning her foot at the same speed.”
That third of a second in the air – the swing time – is probably close to a biological limit. Peter Weyand thinks that there is very little that people can do to improve on it, with a notable exception. Oscar Pistorius, the South African double-amputee, runs on artificial carbon-fibre legs that each weigh less than half of what a normal fleshy limb would do. With this lighter load, he can swing his legs around 20% faster than a runner with intact limbs, moving at the same speed.
For most runners though, speed is largely determined by how much force they can apply when their foot is on the ground. They have two simple options for running faster: hit the ground harder, or exert the same force over a longer period.
The second option partly explains why greyhounds and cheetahs are so fast. They maximize their time on the ground using their bendy backbones. As their front feet land, their spines bend and collapse, so their back halves spend more time in the air before they have to come down. Then, their spines decompress, giving their front halves more time in the air and their back legs more time on the ground.
Such tricks aren’t available to us two-legged humans, but technology provides alternatives. In the 1990s, speed skaters started using a new breed of “clap skates” where the blade is hinged to the front of the boot, rather than firmly fixed. As the skaters pushed back, the new design kept their blades in longer contact with the ice, allowing them to exert the same force over more time. Speed records suddenly fell.
People have tried to duplicate the same effect with running shoes, but with little success. That’s because a running leg behaves a bit like a pogo stick. As it hits the ground, it compresses. As it steps off, it gets a bit of elastic rebound. Technologies that try to alter a runner’s gait tend to interfere with this rebound, and diminish the leg’s overall performance.
“It’s hard to intervene in a similar manner to the clap-skates without buggering up the other mechanics of the limb,” says Peter Weyand. (Again, Oscar Pistorius bucks the trend because his artificial legs are springier than natural ones, and give him around 10% longer on the ground than other runners.)
For those with intact limbs, one option remains: exert more force on the ground. Put simply, fast people hit the ground more forcefully than slow people, relative to their body weight. But we know very little about what contributes to that force, and we are terrible at predicting it based on a runner’s physique or movements.
We know that champion male sprinters can hit the ground with a force that’s around 2.5 times their body weight (most people manage around two times). When Usain Bolt’s foot lands, it applies around 900 pounds (400 kg) of force for a few milliseconds, and continues pushing for around 90 more.
Peter Weyand likes to imagine a weightlifter trying to apply the same force in a one-legged squat – they would come nowhere close.
“What we know about force under static conditions under-predicts how hard sprinters hit by a factor of two,” he says.
“We just don’t have the ability to go from the movements of the body to the force on the ground.”
Even if a sprinter’s muscles were eventually boosted by gene doping techniques, we have no way of calculating how much faster their owners would run.
Studies are underway to fill in those gaps, and Peter Weyand is hoping that we’ll be able to make better predictions in five or 10 years. Just a few months ago, Marcus Pandy from the University of Melbourne used computer simulations of sprinters to show that the calf muscles, more than any others, determine the amount of force that runners apply to the ground. At top speeds, the hip muscles become increasingly important too. “Maybe if you train a sprinter, you could potentially train them to have really strong calves,” says Hutchinson.
For the moment, however, any predictions about the ceilings of human speed are still ill-informed ones. The only way to work out if Usain Bolt or some other sprinter will smash the existing record is to watch them.
Usain Bolt crashed into a flower girl at the end of his 100 m sprint last night in Oslo where he ran the second fastest time this year – he holds first and third place too.
Crossing the line at about 40 mph, it takes Usain Bolt a few metres to slow to a stop. It was during this slowdown that the world’s fastest man clashed with a girl who was there to present flowers to runners.
Video footage shows Usain Bolt avoids one of the girls on the track but fails to see a second just behind her.
He then appears to try and jump over her but, resigned to his fate, grabs hold of her and runs along with her.
She falls backwards but Usain Bolt manages to stop her from actually hitting the ground, pulling her upwards and eventually gives her a hug once he comes to a halt.
Usain Bolt crashed into a flower girl at the end of his 100 m sprint last night in Oslo where he ran the second fastest time this year
World champion Yohan Blake’s challenge awaits Usain Bolt in Kingston – Blake races in New York on Saturday – but in his present form Bolt is a shoo-in for the team his island will send to London.
The collision occurred after Usain Bolt ran 9.79 sec in Oslo on Thursday, he owns the year’s three fastest 100 metres times.
“I am not yet in the shape where I can say, <<Nobody can beat me>>. My start is letting me down slightly still,” said Usain Bolt.
“I can’t complain but the execution of my race was not perfect.”
For that he blamed shorter starting blocks, introduced by Omega this year to Diamond League meetings. They will be used in the Olympic Games.