Spring theory & Bolt


Usain Bolt: Case Study In Science Of Sprinting

Tuesday, July 26, 2011 12:45 am

Written by: Jay Hart

One year from now, the 2012 Olympic Games will begin in London, where all eyes will be on the incomparable Usain Bolt – the Jamaican sprinter who is more than living up to his name.

Since 2008, Bolt has taken a jackhammer to the 100-meter world record, lopping off a whopping .14 seconds. That might not sound like a huge chunk of time until you consider it’s twice as much as any other sprinter has shaved off the world record since the advent of electronic scoring.

Logically, one would think that Bolt did so by moving his legs faster than anyone else. Only he didn’t.

Speed, as it turns out, may be completely misunderstood.

When Bolt established the current 100-meter world record in the 2009 world championships, running it in 9.58 seconds, he did so by moving his legs at virtually the same pace as his competitors. In fact, if you or I were to compete against Bolt, our legs would turn over at essentially the same rate as his.

This is a theory put forth by academics and track coaches alike who contend that running fast has more to do with the force one applies to the ground than how quickly one can move one’s legs.

More than a decade ago, Peter Weyand, a science professor at Southern Methodist University, conducted a study on speed. Comparing athletes to non-athletes, Weyand clocked both test groups as they ran at their top speed. What he found shocked him.

“The amount of time to pick up a leg and put it down is very similar,” he says. “It surprised us when we first figured it out.”

So if leg turnover is the same, how does one person run faster than another?

Weyand discovered that speed is dependent upon two variables: The force with which one presses against the ground and how long one applies that force.

Think of the legs as springs. The more force they can push against the ground, the further they can propel the body forward, thus maximizing the output of each individual step. In a full sprint, the average person applies about 500 to 600 pounds of force. An Olympic sprinter can apply more than 1,000 pounds.

But force isn’t the only factor. How quickly that force is applied factors in as well.

For this, think of bouncing a beach ball versus a super ball. The beach ball is soft and mushy and when bounced on the ground sits for a while before slowly rebounding back into the air. Conversely, a super ball is hard and stiff and when bounced rebounds almost instantaneously – and at a much faster speed than the beach ball.

The average person’s foot is on the ground for about .12 seconds, while an Olympic sprinter’s foot is on the ground for just .08 seconds – a 60-percent difference.

“The amount of time [one’s legs are] in the air is .12, regardless if you’re fast or slow,” Weyand explains. “An elite sprinter gets the aerial time they need with less time on the ground to generate that lift – or to get back up in the air – because they can hit harder.”

So what makes Bolt faster than even the elite sprinters? And can he run the 100 meters even faster than 9.58 seconds?

Bolt’s superiority is often explained by his unique combination of height, strength and acceleration.

At 6-foot-5, Bolt is two inches taller than fellow Jamaican Asafa Powell (pictured together below) and has six inches on American Tyson Gay – two of his closest challengers. While it takes most elite sprinters 44 strides to complete 100 meters, Bolt does it in 41.

“Would you rather take 44 steps to your car or 41?” asks Dan Pfaff, who coached Canada’s Donovan Bailey to the 100-meter gold during the Atlanta Games in 1996.

Pfaff, now working in London to help boost Great Britain’s track-and-field hopes for 2012, says Bolt’s height gives him a distinct leverage advantage.

“If you’re digging a hole in the ground, you have to get a longer lever to pry [out a rock],” he explains. “If you can control those levers and make them work efficiently, it’s a huge advantage.”

It’s Bolt’s ability to control the levers that is so unusual for a sprinter his height.

While taller sprinters may be able to reach a higher top-end speed, getting up to that speed isn’t as easy. This can be explained physiologically – smaller people can exert more force in relation to how much they weigh – but Weyand prefers a more simple visual to show this to be true.

“You can easily imagine a 4-foot-10 gymnast doing a triple back flip, but imagine Shaquille O’Neal or Yao Ming doing it,” he says. “You know they can’t do it.”

Bolt, it seems, is the exception to this rule. Though he’s not doing triple back flips, he does get up to speed nearly as quickly as his more diminutive competitors.

“He has a very unusual combination of being extremely tall and relatively massive and being able to accelerate well. Those things are at odds with each other,” explains Mike Young, a strength and speed coach who’s tutored several collegiate national champions.

“He accelerates better than all but one guy in the world – behind Asafa Powell – but because he’s so massive, he takes fewer strides. If you’re that large, once you’re moving, you stay moving.”

This would help explain why Bolt still managed to break the world record during the Beijing Games in 2008 despite throwing up his arms in celebration some 20 meters before the finish. As Young explains, if the “average athlete is a motorcycle, Usain Bolt is a dump truck,” and it takes a lot more resistance to slow down a dump truck than a motorcycle. Thus, when he fatigues, he slows down more slowly.

“He has the holy triumvirate,” Young contends. “He’s one of the top accelerators, has the highest top-end speed and the highest endurance. It’s something that’s never been seen before. Carl Lewis had the highest top speed, the highest endurance, but he was not the best accelerator.”

Bolt, just 24, has set his goal of running the 100 meters in the 9.4 range, explaining to Britain’s BBC Radio: “Because that’s where I think the record will probably never be beaten.”

While Young doesn’t think Bolt will break 9.5 in London, Weyand, through his research, says it’s possible. Though if Bolt pulls it off, it won’t be because he moves his legs any faster.

carl was not the best accelerator due to the fact that TT thought carl how to accelerate smoothly. with a PR of 6.61 in the 60m thats good acceleration. Burrell,Marsh,Witherspoon etc all accelerated smoothly because thats what was thought day by day to them by tom, just the same as smith with the hsi guys in regards to head down.

ii agree totally with lorens laws of the levers. the longer the lever the greater the force/leverage as this applies to everything within force/pressure but bolt is not the holy grail of sprinting! ill not go into great detail but i have my own thoughts which ill keep to myself in regards to usian

during frankie fredericks fantastic season in 96(i think) he was banging out 9.8s every week and he was asked what he did differently…his reply was he decreased his stride lenght and focussed on frequency! thoughts!?

Yes, and thats exactly Christophe Lemaître’s coach advice.
He said that if Lemaître managed to increase his frequency in the last 20 meters and reduce his stride he would be much faster.
Of course it doesn’t mean he could automatically challenge Bolt, Powell, Gay, Blake…
That being said Bolt can run in 41 stride, and due to his power and technique he does not overstride to do it.
Running fast is theorically easy : fast frequency & long stride. But the issue is not how good the acceleration is, or which top speed one can reach, or how many or how long the stride, but what time one can run. Bolt is unique and I guess what works for him won’t necessarily works for other.
Each sprinter should run with his own attributes.
If Maurice Greene was to challenge Usain Bolt, I am sure he would still run his race in 45/47 strides because this form suits him the best.
Bolt is becoming such an icone everyone looks up to him and try to copy him, but for one 6’5 top level sprinter how many are around 6 feet?

stride lenght+stride frequency+ana.endurance=sprinting. i still dont think bolt is an icon. ben was alot shorter than bolt and honestly ben would have been just as or if not faster then bolt!

WHY? track surfaces have changed ie…mondo surfaces
design of spikes have increased significantly and r more stiffer plates
supplements have changed LOL
although coaching has not changed alot therapy etc has changed with the introduction of newer recovery aids…

It’s the sweet potatoes.

I agree with everything you said. Its sad that many people dont even realize how fast ben was for his time. Im sure ben would have put so much pressure on bolt that he would have nutted up. The only person i think would have matched ben’s start would be asafa. But I dont know what asafa would have done with been toward the end of the race.

just look at Soeul 88 and his acceleration at 30 and 60m is crazy. at 80 he had 2+ metres on lewis and then he looks around and shuts off WOW! honestly i think he’d blow bolt off the track even by looking at him. imagine 9.79 in 1988 while easing up! his diadora shoes werent exactly as up to spec as lewis’ shoe in 91 which was incredible by mizuno. mizuno even threaded his laces a certain way to reduce weight, they used colours for a specific reason and they were lite years ahead and still are!

im not a crazy BJ fan but what he and charlie did was incredible…INCREDIBLE! bolt would be a pussycat in the jungle compared to ben being a lion! meet promoters are happy with bolt due to crowds etc etc etc…as a moderator i must zip it sorry guys

Exactly! I’m tired of everybody riding bolts jock and using him as some kind of lab rat to study sprinting. Bolt is only 1 of MANY great sprinters that have walked the earth and it’s a disservice to other great sprinters to say he’s the holy grail just because he’s number 1 AT THE MOMENT.

While I’m at it, I get mad when I watch sprinting on TV because the commentary and focus is always on Bolt! Why?! There are 7 other lanes with people in them for god sake!!!

Rant over.

+1 I agree.

Yea, only sprinters and people who study sprinting really know what the deal is. I got into an argument last with with a dude who tried to discredit Ben and say Carl was the better 100m sprinter.

Coming away from that argument I realize that it’s all about IMAGE and how the media shapes people to think of others. People are so dumb, they never investigate things on their own to see for themselves if something is really true or not.

In regards to track surfaces and “what could have been done on today’s surfaces” let’s not forget about who may have been the fastest sprinter of all time: Bob Hayes

As to the question of sprint mechanics, there’s no question, in my view, that not only must the dynamics be individualized in order to suit each sprinter’s anthropometric proportions; but also their output potential at any given time (which obviously develops up to their peak)

I still think it’s fascinating that Nesta Carter essentially goes into complete knee extension prior to ground contact; hence, obviating “stepping down”. Something that Mo Greene also seemed to do which is really pronounced on the 6.39 in which he jumped but didn’t get called.

Yea the average american hates ben cause he was a cheat. I have made so many sprinters open there minds by making them read speed trap and watching bigger stronger faster.

lets not forget that mo ran it twice!

Very true. I have made friends with a fellow who ran 10.2 and trained with others who were in Charlie’s camp in the early 90’s as well as other high level coaches. He has shared some great stories with me.

In regards to track surfaces, bought the 2002 forum review last week and Charlie said that Ben ran something like 10.01 100m on grass. That said, is it safe to say synthetic tracks allow an elite sprinter to run around .20 faster?

As far as Bob Hayes, I’m afraid I’m not qualified to say much about him because it’s hard to me to compare sprinters when I dont have any splits and I’m not like PJ and others around here that are experts in analyzing flim. Split recordings started around 1988, no?

I don’t recall when FAT splits first became available.

As far as track surfaces go, I wouldn’t be surprised if the difference between two synthetic tracks spanning from the premier tracks of today to 20 years ago is in the 1.0-2.0 range; let alone the difference between today’s premier tracks and what Hayes was running 10.06 on nearly50 years ago

I have made friends with an American/Aussie who ran 10.3 and we had a bit of a private session, he asked if I had trained under Pfaff and he suggested I have taken what he was taught 20 years ago one stage further.

All these so called scientific studies are just a means of getting government funding, horseshit

Hence the beauty of what’s been and is currently investigated by the former and current communist/socialist regimes because, to the contrary, the state supplies so much of the backing in the interest of using athletics as a political weapon.

So the question is: who will be the first capitalist society to employ state sponsored athletics support proportional to the former USSR, GDR, and current China?

Who would you suggest, most of us know of undercover facilities but nothing like the former CB countries had.

What I know for sure is that my own country is likely at the bottom of the list of candidates. Considering our diverse gene pool it’s a travesty.