Usain Bolt 9.55s? Yeah, right  //  Could Usain Bolt have run 9.55s without his celebration in Beijing? Not a chance…

12 Sep 2008 Posted by
Click here for our detailed analysis of Bolt’s 9.58s time, including Bolt’s splits, speeds and a comparison with his previous world record in Beijing.
Late edit to this post (NB):

If you’ve arrived here in the aftermath of Usain’s amazing 9.58s WR in Berlin, I must emphasize a very important point: This post was written back in September 2008 to answer the question “Could Bolt have run 9.55s without celebrating in BEIJING?“. It was NOT written to say that Bolt would NEVER run 9.55s. So if you are here to point out that he just ran 9.58s, yes, you are quite right. And yes, 9.55s is on the cards. But this post, I must stress again, looked at the very specific issue of Bolt’s 100m in Beijing, and whether he might have been able to run 9.55s in BEIJING. The post was written in September 2008 – we are now a year on, so to use this to prove your point…well, you’re in the wrong place.

If you would like to read the latest thoughts on the Bolt 9.58s WR, and if you’re wondering what Bolt is really capable of, as well as the rest of our coverage of athletics, please click here.

Yesterday, the news wires were buzzing with the news that scientists in Oslo predicted that Usain Bolt, Jamaica’s triple Olympic champ, would have run 9.55 seconds had he not celebrated prematurely in his 100m final in Beijing.

It was on the radios, internet, TV news, all over. A while back, just after that race, we speculated that a 9.61s time was about the limit, given the split times that were available.

So this 9.55 s is quite different from that. And far be it from me to criticize the physicist’s assumptions, and calculations, but what we have here is a classic case of losing sight of the wood for the trees. Their method involved looking at the final 2 seconds of the race, where Bolt began his celebrations, and compared his acceleration to that of Richard Thompson, who finished second. They looked at two possible outcomes: One is that he maintained the same acceleration as Thompson (that is, slowed down, because all athletes slow down at the end of a 100m race), and the second is if he maintained an acceleration 0.5m/s2 greater than Thompson.

It was in the second of these scenarios that they worked out that he’d run 9.55 s. But the problem with this emerges when you consider the official 10m splits from the race, courtesy the IAAF analysis and a website in which they discuss the race.

So let’s look at the analysis, and let me start by asking a simple question: Where in this race are you going to find 0.14 seconds to help Bolt run 9.55 seconds? The answer, as you’ll see, is that you won’t find it at the end of the race, in the celebrations. It’s just not physiologically possible…

The splits:

These are the split times from Bolt’s race, according to the IAAF analysis. The graph below it shows the times making some basic assumptions (apologies for the lack of integration and physics equations, but I wish to make a point using simplicity as the vehicle). Again, ask the question: Where are you going to help Bolt knock 0.14 seconds off his time?

bolt-splits-2008-beijing

bolt-performance-2008-beijing

The RED line represents the ACTUAL PERFORMANCE. It adds up to a time of 9.685 seconds, considering also that Bolt’s reaction time was 0.165 seconds. You’ll note that Bolt’s fastest 10m interval was from 60 to 70m, taking 0.82 seconds. I must point out that no one has ever measured a human being running a 10m interval faster than this. In our analysis of the race, we got a lot of interesting discussion and data from people, and of all the recorded 10m split times, this is the fastest ever measured. To speed up for the remaining 30 m would represent not only the fastest splits ever run, but also the longest period for which they are ever run.

That’s not to say, of course, that Bolt would not be able to run a 0.80s segment. But the key is the pacing strategy – nobody speeds up progressively all the way to the finish line. Nobody. There are mechanical and metabolic reasons for this, but the point is that even holding that speed would be unusual, and speeding up would be highly, highly unlikely. Note, for example, that Bolt has already started slowing down BEFORE he starts celebrating. According to the splits, Bolt slows from 70m to 80m. The celebrations started at 80m. So speeding up? I don’t think so.

The BLUE line, to simplify, represents Bolt’s projected splits if he continues to accelerate. This is effectively the assumption made by the physicists when the calculate his 9.55 second time. I must emphasize that if you want to find 0.14 seconds at the end of the race (and answer my simple question), then you HAVE TO project that Bolt continues to speed up.

According to this assumption, Bolt would run faster and faster – he has to, in order to do what was projected by the analysis. Again, I must stress that this has never been done – I believe it to be impossible to speed up this much after 70m, and even Bolt would have slowed, or at the very best, held his speed. The whole basis for the argument by the physicists is flawed because there is no reason to believe that Bolt would continue to run faster than Thompson, or accelerate.

The GREEN line represents what I would in fact consider a more likely scenario. In this case, Bolt maintains that top speed that he hits between 60 and 70m. He thus runs the final 30m at 0.82 seconds/10m speed. If he does this, then he run 9.605 seconds.

In reality, I suspect that Bolt would slow down at the end anyway, even without his celebrations. His most likely performance is thus somewhere between 9.61 seconds and 9.69 seconds.

Now, I know there’s no fancy physics here, no integration. Just split times, and a very simple question: Where in this race are you going to find 0.14 seconds to help Bolt run 9.55 seconds?

Answer, you can’t find that time at the end of the race. Unless you assume that Bolt is going to run a 0.79 second 10m interval somewhere in the race. But that, I’m afraid, is not possible, and therefore, you cannot conclude that he would have run 9.55 seconds without celebrating.

What is possible? There is still time to be made up, but it wasn’t the celebration

Having said this, I make the suggestion that Bolt’s CELEBRATIONS cost him only about 0.05 seconds. However, that’s not to say he cannot still run under 9.60 seconds.

One area for improvement is the start – a reaction time of 0.165 seconds can easily be cut down. Asafa Powell, for example, had a reaction time of 0.134 seconds in Beijing. Therefore, we can estimate that Bolt might get a 0.140 second reaction time.

If that happens, then suddenly he’s down to 9.66 seconds. Add to this the fact that there was no tail-wind in Beijing, and it has been estimated that a tailwind of 1m/s improves 100m times by 0.05 seconds. Therefore, on an ideal day, with a tailwind of 1m/s (it could be as much as 2m/s, recall), a super fast reaction time, Bolt could run 9.61 seconds, and still celebrate. Take away those celebrations (another 0.05 seconds, in my estimation), and we have a 9.56 seconds.

But there is no way the 9.55 second time would have come without those celebrations – the trees just got in the way.

Preview of forthcoming attractions. The Coyle-Armstrong debate

A big debate has flared up in the last few days, ignited by Lance Armstrong’s comeback. It turns out that Ed Coyle, he who published a paper that “proved” why Lance Armstrong was superior without doping, has admitted that he may have made “some mistakes” in that paper. He only did so under pressure from the University of Texas after fellow scientists lodged a formal complaint of scientific misconduct against him.

The paper [1], which you can find here, showed that Armstrong improved his muscular efficiency over the years, but it was fraught with problems. In fact, it became a running joke within sections of the scientific community. That didn’t stop Coyle from using his data to testify at a legal hearing that Armstrong had a physiological reason to have dominated without using drugs. It was a shameful display of science meets money meets tacky indulgence, and loses all credibility.

In response to the latest “attacks”, Coyle had this to say:

“This is a minor waste on my time. However, I don’t understand how they can afford to spend so much time on this. Don’t they have real jobs?”

Well, yes, Ed Coyle, they do have jobs. They are credible scientists, who search for the truth. But then aren’t we all?

So the announcement, and the challeges to the Coyle paper are more than welcome. We’ll look at the issue early next week. So join us then!

Ross

References

  1. E.F. Coyle, “Improved muscular efficiency displayed as Tour de France champion matures”, Journal of Applied Physiology, vol. 98, pp. 2191-2196, 2005. http://dx.doi.org/10.1152/japplphysiol.00216.2005

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