Welcome to the Science of Sport, where we bring you the second, third, and fourth level of analysis you will not find anywhere else.

Be it doping in sport, hot topics like Caster Semenya or Oscar Pistorius, or the dehydration myth, we try to translate the science behind sports and sports performance.

Consider a donation if you like what you see here!

Did you know?
We published The Runner's Body in May 2009. With an average 4.4/5 stars on Amazon.com, it has been receiving positive reviews from runners and non-runners alike.

Available for the Kindle and also in the traditional paper back. It will make a great gift for the runners you know, and helps support our work here on The Science of Sport.

Thursday, July 17, 2008

Oscar Pistorius: Remarkable physiology

The Remarkable Physiology of Oscar Pistorius

This morning, my email inbox was full of stories about Oscar Pistorius contemplating legal action against the IAAF for trying to exclude him from selection for the SA Olympic team. The grounds for his 'legal action'? Two reasons:

First, the IAAF last week suggested that Pistorius would be dangerous in a relay event, where the athletes are all bunched together at the change-over point. This would increase the risk of falling or clashing with another athlete. Athletes are often spiked in these 'close contact' situations, but of course the presence of carbon fibre blades poses a big risk for other athletes.

Can you imagine the fall-out if Pistorius cut LaShawn Merritt, for example? The defence put forward by Pistorius is that he'd run the first leg of the race, which is run in lanes. This of course, would be a crazy decision by Team South Africa (one I suspect they'd make, admittedly), because Pistorius big advantage would come when he has a running start. If he does start, then Team SA would lose perhaps a second. They would, of course, benefit from all the PR reasons and exposure they'll gain, which is why I think they'll pick him even though he hasn't qualified. Nike and Ossur's millions are hard to refuse...

The second grounds for Pistorius' threat is that the IAAF have suggested that it is impossible for them to monitor and regulate the use of the prosthetics. The CAS decision, you'll recall, was the Pistorius could compete IF he used the same prosthetics that were tested, first by the IAAF and this is team of scientists. The problem is, the IAAF testing cost 50,000 Euros, and I have it on good authority that Prof Herr, who led Pistorius' case, says their defence cast cost $1 million, with hundreds of thousands going to the science part.

Legal action for saying the truth

Now, in the aftermath of the CAS decision, many people were saying exactly these two things. First, how on earth would the IAAF enforce the ruling without the possibility of "cheating" by bringing out new blades? Subtle changes, worth half a second here and there, are not beyond the realms of possibility. And many people were worried about this relay participation. The IAAF have merely expressed what everyone else is thinking or writing. And for this, Pistorius is threatening legal action (again).

Well, perhaps Pistorius might wish to sue everyone who speaks the truth. And if you keep reading, you'll learn a truth or two about physiology that we've never seen before...

Pistorius' remarkable physiology: Never seen before

About two months ago, I did a post on Pistorius in which I made some arguments why the CAS decision was incorrect, and that the evidence presented by Herr and his team of scientists was flawed. I said at the time that evidence would emerge, the "truth" would gradually come out, and it would become apparent that what Pistorius did was bend the system. Effectively, he asked the right question, the unanswerable one, and now feels that he has been "cleared".

Let's remember, that the absence of evidence is NOT the evidence of absence. The CAS made their ruling based on the flawed information presented to them, and legally, made the only decision they could. But time will reveal a more detailed analysis of that "evidence" and there will be flaws. And the first of those flaws is ENERGY-GENERATION. For this, I'll do the post somewhat differently, using graphs to explain the physiology. So bear with me as we explain how Pistorius' own testing suggests that he has an advantage.

Where does the energy come from? The IAAF science vs. Pistorius science

If you think back to January, the IAAF testing found that Pistorius used 25% less oxygen to run at 400m race pace than able-bodied runners. The graph below summarises this, and the conclusions drawn.

The problem, which was freely admitted, is that the measurement of oxygen during sprinting, represents only part of the TOTAL energy. Energy comes from TWO SOURCES: Aerobic (using oxygen) and Anaerobic (without oxygen). Therefore, the conclusion drawn by the IAAF is only partly correct - it should say that he uses 25% less AEROBIC energy during 400m running.

Pistorius and his group challenged the finding on these grounds, asking the question "What about the anaerobic component of 400m sprinting?". We know from numerous studies that the split between the two is roughly 50-50, perhaps up to 60% for anaerobic sources.

Now, this is A CRUCIAL POINT, but when you do a 200m race, about 70% of the energy is ANAEROBIC, and in a 400m race, it falls to 60%. It's not possible to run a 400m race with much more anaerobic energy than this, because it means that too much energy is coming from anaerobic sources, and this is associated with fatigue, because of changes in ATP production, pH levels and lactate formation.

Pistorius' response: Ultimately proving his own advantage

So, the response by Pistorius was as follows:

Now, there are two problems with this assumption:

FIRST: The carbon-fibre Cheetahs are designed by Ossur specifically for speed and sprinting. How can you assess them at slow speeds and then infer upwards? That test suffers from a problem of what is called external validity – it’s irrelevant to answer the actual question of Pistorius’ 400m race.

SECOND: The RELATIVE proportion of the two energy systems must still be similar. The IAAF finding suggests that Pistorius uses LESS aerobic energy. There is no reason to believe that he would not also use less anaerobic energy, because the two systems act in proportion. Unless of course, you believe the argument of Prof Herr, who is suggesting that Pistorius uses MORE anaerobic energy than anyone else. Note that they did not measure this, it's a bald assertion, the kind they themselves criticize when others make it. It's also incorrect, and physiologically impossible, as we'll see shortly.

The truth about energy production

The sequence of graphs below shows the problem with the Pistorius science. And then after that, the MILLION DOLLAR QUESTION that Pistorius cannot answer without suggesting his own advantage.

Firstly, let's take a typical able-bodied runner, who gets 40% of their energy aerobically, and 60% anaerobically. If we assume 100 units of energy, the graph above shows the breakdown.

So, if we take the IAAF finding that he uses 25% less oxygen, then we see that he uses 30 units of aerobic energy. The Pistorius scientists contest this, and there are some theoretical arguments around measurement of oxygen during sprinting, but it has been done many times, and used in many studies, so this is not science-fiction, but validated science.

Now, the big question is how much energy does Pistorius get from anaerobic sources. And there are three possibilities here:

The implications of each of these options are profound:

Option A:
Here, Pistorius uses the SAME TOTAL energy, which means MORE anaerobic energy must be used to bring his TOTAL up to 100 units – his ratio is 70 units ANAEROBIC, 30 units AEROBIC. Note that the numbers are arbitrary, but the point is that he uses upward of 15% more anaerobic energy to compensate for the reduced aerobic energy. Note also that there is no basis to suggest that this would ever happen. Herr and Weyand couldn't tell you the reasons, and they only measured lactate levels to check this. They found similar lacate, which actually suggests that this would NOT happen, incidentally.

Science does not know the exact reason, but it’s physiologically impossible to run 400m with this large an anaerobic energy contribution – theories range from pH changes to lactate accumulation to phosphate (or other metabolite) depletion.

If this is true, Pistorius is effectively running a 400m race as though it is a 200m race, and should not be able to run more than 200m before he’d fatigue and be forced to slow down, unless….

He was immune to this fatigue, as a result of his carbon-fibre blades which do not experience the same fatigue as muscle. Therefore, Pistorius has an advantage.

Option B:
Pistorius uses the SAME ANAEROBIC energy, which means LESS total energy is used. His ratio is now 67% ANAEROBIC, 33% AEROBIC, but total anaerobic energy is the same.

This means that Pistorius has an advantage because his total energy use is reduced. Why would it be lower? Because the carbon fibre blades provide energy returns that are FAR GREATER than in able-bodied runners, giving him this advantage.

Option C:
This is the most physiologically likely possibility, because here, Pistorius' anaerobic energy contribution follows his aerobic contribution - both are lower.

There is no physiological explanation for why Pistorius would use more anaerobic energy. Instead, the knowledge suggests that whatever is causing the aerobic energy to be lower will also reduce the anaerobic.

Therefore, Pistorius' total energy production is down considerably to run 400m. Pistorius has a substantial advantage, provided by the higher energy return of the blades, which means less demand to produce metabolic energy for muscle contraction.

But the million dollar question, and the most telling finding so far, is yet to come.

What is described above is that no matter how you look at it, it's simply not possible to conclude that Pistorius does not enjoy a physiological and metabolic advantage during running at 400m speed. Either he is "unphysiological" as a result of higher anaerobic energy, or his total energy is lower. His own data suggest this.

About a month ago, I was doing a radio interview on this and was suddenly struck by an epiphany, that Pistorius had in fact proven his advantage.

Remember that when Herr and Weyand did their research on Pistorius, they made him run at slow speeds and measured his oxygen use. They found that at slow speeds, he used similar amounts of oxygen as the able-bodied runners to whom he was compared.

But when the IAAF tested Pistorius at 400m race speeds, they found he used 25% LESS oxygen than able-bodied runners.

So, here's the situation:
  • At slow speeds, you have a runner who uses the same oxygen as able-bodied runners.
  • At high speeds, he uses less oxygen than them. (the issue of controls is a major one, and I'll touch on that in the future - Pistorius' team used some dodgy control subjects)
So, how does a runner go from slow speeds to high speeds and not increase his use of oxygen like able-bodied runners do?

The answer can only be that he is getting a mechanical advantage that allows him to run faster. He gets a mechanical advantage from the blades that the able-bodied runners don't enjoy. They must produce more energy from metabolic sources, and hence increase their use of oxygen relative to Pistorius. That is, in a single question, the most telling evidence yet that an advantage exists.

What next? Olympic selection for Pistorius

If you've been following the story, you'll know that Pistorius has now missed the A-standard to qualify for the Olympic Games. But that's not the end of it. There is still the relay, and the very real possibility that he'll be picked despite not qualifying.

The Olympic Games allows this, so there is nothing wrong with it from a legal perspective. However, it does mean that SA Olympics selectors will have to pick a guy based on projected times in Beijing, and overlook any number of athletes who have not qualified.

Why would they do this? Well, because, according to Prof Hugh Herr, Oscar's defence case cost $1 million. Remember that everyone is claiming that the legal and scientific work was done "pro bono". That may well be true, but make no mistake, there is a massive army of sponsors and funders behind Pistorius. And now tell me, who spends $1 million to get an athlete cleared (you can buy freedom in the legal system, just not in science) and then doesn't mind if he doesn't run?

So the commercial pressures on South Africa's Olympic team (I'll vouch for those as a SA local), plus the opportunity to gain exposure means Pistorius will, in my opinion, run in Beijing, confirming that the Olympic dream has a price. But the physiology doesn't lie, the advantage exists.

And that is truth.


P.S. The purpose of this site is to stimulate discussion and debate, and obviously to provide insight on topical sports news. The Pistorius issue does all three. And therefore, I have no doubt someone will challenge part or all of the science in this post. That's fine, but can I ask that if you do challenge the science, at the very least state a logical case rather than just pointing out "you're wrong", as has been done. I'm all for debate, but pro-Pistorius people (and his team) have shown little capacity for this in the past. I've had some excellent, thought-provoking correspondence from one or two neutrals, but they are few and far between.

Indeed, one of the biggest problems in this whole case is that the IAAF science was released in January, giving Pistorius three months to criticize it and prepare a defence. To this day, the Pistorius science has not been fully released. When that' science is eventually made available, it will be easy to pick apart, as I've done for only one aspect here. The problem then, is lack of debate and opportunity for discussion. The CAS verdict was based on unequal information and opportunity, because scrutiny of Pistorius' science will reveal its flaws.

So if I'm wrong, let me know why. And explain the results your way, rather than simply trashing the messenger.


nc1984 said...

I must say that I find this post very enlightening. It makes you think and that is really one of the purposes of a scientific education. This post has very solid arguments about Pistorious's advantage, but it would be great to have experimental data (do we have it already?) that can be directly linked to his advantage.

It would be nice to do also a analysis to his 'Cheetas', just to check its mechanical properties, strain, stress factors,etc...

Science can provide the answers, but 'law' can buy any answer (well the world isn´t perfect right...).

keep the good job because I really enjoy reading the sportsscientists...


Ross Tucker and Jonathan Dugas said...

Hi Nuno

Thanks a lot for the comments and positive feedback. That's exactly the point of scientific education, which is part of the idea, as I mentioned.

Just to respond to your question, all the testing by the IAAF has been done - click on the "Topical News Stories" tab at the top of the page and you'll see all those stories.

There is one, number 5, that explains the IAAF testing more. They did test all the mechanical properties and found large advantages there. The Cheetahs lose only 8% of their energy, compared to 40% for able bodied runners' ankle joints.

I think you'd find that post, along with the links to other articles, quite interesting!

Thanks again!

Julie said...

Great analysis, as usual. Thanks!

Anonymous said...

Hi Ross,

Excellent post once again.

Your post assumes that all runners who run 400m should consume an identical amount of energy (aerobic+anaerobic). Thus, when Pistorius uses less energy, he gets an advantage (presumably from the blades). Please can you elaborate more on this point - Do all elite able bodied athletes consume an identical amount of energy ? Is there no significant difference in the efficiency of elite athletes ?


Andrew said...

Excellent coverage of this topic! Two questions:

1) If Pistorius continues to accelerate in a 400m, would he be even better at longer distances? A lane-less race could pose traffic problems, but are you aware of any time trials he's run at 800m, 1500m, or even 5K?

2) One of your earlier articles mentions a reporter trying out a pair of Cheetahs mounted to boots. Has anyone experimented with simulated prosthetics on able-bodied runners to compare the physiologies? It's not perfect, but might shed some light on muscle activation, O2 usage, ground forces, etc.

PecosPeet said...

Picking up on Vikram's question:
From my very basic understanding (which might be very wrong!) I think it requires the same amount of energy to get a person from point A to point B. So if I walk the 400 metres and both Pistorius and an able bodied elite run it, the amount of energy required to get there is the same. There is a difference bvetween our three modes -- the energy lost due to absorption. So the total energy expended is the amount to get from A to B plus the energy lost.

It seems to me that I would actually use less total energy to walk the distance because I lose less through walking than running. (Do I??)

Simplistically, what appears obvious to me and what I think underlies Ross' position is basically related to the spring and flexibility of the Cheetah - with less loss of energy.

So Ross, have I missed something important or am I getting this in my simplistic way?

Possibly related, does the cushioning in my shoes help or hinder the energy I need to run? The shoes absorb some of the shock - but does that reduce the energy loss, increase it or does it remain the same? Do the shoes do something similar to the Cheetahs, but just to a much lesser degree?

I wonder if mini Cheetahs embedded in my shoes would help make me run fast enough to get to the Olympics - except I'm probably way too old.


Will said...

While you say that Pistorious's legal team asked the wrong (unanswerable) question, I think you may be going down the same road a bit yourself. Now I'm not trying to claim that in this case Pistorious should be allowed to run, I would guess not. But it also seems a bit unfair to use a pure energy consumption test to see if he's getting an unfair advantage. I’m pretty much formulating this argument as I go along, so please bear with me as I’m sure I’m not stating it as well as it could be.

Assuming that someone has had a portion of their limb removed, they would then pretty much by definition have less muscle mass than a fully limbed person would (everything else being equal). And if they have less muscle mass to produce (transform?) the necessary energy for forward motion, it seems that one shouldn’t expect to see the same overall level of energy production out of the person. If we assume that we as a species have gotten pretty good at getting the maximum possible energy production out of our muscles for this type of event, then it would seem impossible for Pistorious to produce the same amount of energy using “less muscle”.

It seems to be the question really should be more along the lines of, with the muscles that he has left, are those muscles producing the same energy that the same muscles in a fully legged person would?


Anonymous said...

It's a shame that this topic has been so controversial; there's some interesting physiology involved, and it could lead to a better understanding of prosthetics in general.

I must say that Oscar Pistorius reminds me a bit of a kangaroo! I don't mean this in a pejorative way, and I don't want to denigrate this remarkable athlete, but there does seem to be a physiological similarity. The oxygen consumption rate of kangaroos increases very little as the kangaroos hop faster, because they gain more energy return from their stretchy tendons when they travel at faster speeds. (In fact, they use less energy to travel a given distance when moving faster.) Pistorius, too, seems to gain more energy return from the Cheetahs when he travels faster.

Perhaps studies done on other species could help us better understand our own.

Anonymous said...

Wow, that was the single most interesting physiology article i have ever seen on the internet. It all seems so obvious!

Great post guys, keep up the good work.

Anonymous said...

Sorry for the double comment.

Thinking about something Pecospeet said, it seems to me that you can only lose energy due to absorption if your feet are on the ground. If I'm walking, my feet are on the ground for a much longer time that if I'm running...

Anonymous said...

Brian, when you say gain more energy , would that mean they loose less energy and become more efficient ?

Peet, thanks for the answer. When you say an identical amount of energy, would that be identical amount of energy per unit mass ?

Also, I think Ross has discussed a bit about this topic here though I admit, its a little hard for me to fit all the pieces together.


Anonymous said...

I've been following your posts on this with interest.

My problem with your position is that you seem to have a narrow understanding of what 'fair' competition is.

By that I mean, what about all the other factors that take place in an athletes life and an athletes training that impact on their achievements.

For example, is it fair that richer countries are able to spend substantially more on developing their athletes skills (and enabling greater access to higher quality coaching, technology, competition etc.)?

What about individual life issues that athletes must deal with? (disability being one of them).

I'm not saying I disagree with your basic points, I'm just unsure about your basic premise of 'fair' competition. Fair is an issue that can't be limited to physiology but must take into account the broader social, economic, psychological and technological realities.

As you can probably guess by my comments, I'm not too sure 'fair' is the best way of describing sport, particularly in the 21C.

At any rate, I'm really enjoying your posts.


Ross Tucker and Jonathan Dugas said...

Hi everyone

Thanks for the comments and questions. I'll do my best to answer them in this single post.

To Julie

Thanks a lot! Always good to hear from you!

Then, to Vikram:

Good question. As PecosPeet has mentioned (not oversimplified at all - simple is the best way to explain anything!), under normal circumstances the energy requirement for running is mostly a function of mass and speed. So if you take two guys with similar masses and have them run 400m in a similar time, the energy cost will be roughly the same, with the only difference coming from metabolic and mechanical inefficiencies.

Metabolic and mechanical differences account for running economy, as Vikram has mentioned in a later comment. The size of the possible difference in economy during sprinting is difficult to establish, but it's certainly not 25% - look at the variability in the data from the IAAF study by observing the error bars on the very first graph in this post, and it's quite clear that Pistorius is way under the range. So natural variation won't account for this, I'm afraid.

Now, the point here is that total energy cost can't simply be measured simply by looking at distance covered in a certain time, because an able-bodied runner must invest so much more energy than Pistorius. The useful energy is the same, but it comes from different sources. Pistorius only loses 8% of the energy that was stored in the cheetahs, according to the IAAF testing. An able bodied runner loses 40% or more - this finding was disputed, though with little basis, as I'll cover in the future.

The point is, the mechanical energy loss from the Cheetahs is so small that the energy taken by Pistorius to run the distance would be lower. This is Option C in the post above.

However, even if this is not true, and Pistorius tries to dodge the issue by claiming that he's an "outlier" and uses lower energy naturally, he still has to account for 25% less oxygen, and also the remarkable finding that he is able to run faster without the same kind of increase in oxygen use as able-bodied runners.

Of all the things mentioned so far, that to me is the most telling. It's remarkable, and like Brian says, he's a kangaroo...

To Andrew

Good questiona bout the longer distance running. About a year ago, it came up and the prediction was made (not only on this site, but others) that if Pistorius ran an 800m, he'd be formidable. You can check out all those stories if you click on "Topical news stories" on top of the page. I honestly believe that he would be a better athlete the longer he goes, but of course that would reveal the advantage so clearly, that it's never going to be done.

One point I wish to make is that we've never seen such a "slow" athlete (over 200m and 100m, that is), run a 46 second 400m time. Most people with Pistorius' 100 and 200m times run in the 48second range. That cannot be explained by his slow start only.

As for the Cheetahs mounted on boots, how I'd love to get my hands on those. I don't know if it's been done, but I'd certainly do it if I could!


Will, thanks for the question. You're quite right, except you've missed the last 15 months' worth of arguments, I suspect! You'd be 100% correct if this was the only issue I had raised. But more than a year ago, all these issues you mentioned were discussed, and since that, I've covered them as the story has unfolded. So if you click on "Topical news stories" on the top of the page (the Maroon tabs), you'll see a list of articles on Pistorius, and while they're long, they do cover all the relevant issues (in my opinion).

Just to pick up on the very specific issue here, Pistorius "only loses" 3 kg thanks to the limbs. They're important 3kg for running efficiency, but that's an advantage, as I've pointed out in the posts I've refered you to. So the lower oxygen cost of running is predicted based on the model for why he'd have an advantage, but it's not simply a function of having less muscle.

You might find answers to your question in those older posts, though.


Thank you for sharing that. I must confess that the kangaroo hadn't crossed my mind as an example, but now that you bring it up, it's a good analogy in terms of the improving efficiency at higher forces and speeds. And you're quite right, studies outside the narrow scope of exercise would reveal a great deal!


Thank you for the kind words - that is lofty praise indeed!

To respond to you and Peet, the harder the surface you run on, the lower the energy loss. That, incidentally, is why they now design athletics tracks to be as hard as possible. The hard surface allows faster running because less energy is lost on ground contact. So, applying this to shoes, a very soft, cushioned shoe is not a good "sprinting" shoe - sprinters wear very stiff spikes, as you'll see if you ever compare sprinters shoes to long distance runners shoes. The stiffness is crucial, because it reduces energy loss. Pistorius gets this advantage throughout the leg, and then some, because he doesn't have a ankle joint, where a great deal of friction causes a lot of energy loss.

Just to pick up on the energy loss issue and comparing walking to running, remember that muscle contraction requires energy, in the form of ATP, and the more forceful the contractions, the more energy is required. So the investment of energy is very much proportional on the speed of movement (or time taken to move, put differently). So running involves a lot more energy use than walking, because the investment of energy is so much higher. interestingly, you do lose LESS energy running (or hopping) than walking, because your muscle-tendon fires more and the energy that is stored is harnassed and released more effectively.

Wow, what a long answer. I hope everyone got their replies!

Thanks for the input!


Ross Tucker and Jonathan Dugas said...

Hi Kira

Thanks for the post, I appreciate your thoughtful manner and objective method of putting the question forward!

To respond, I certainly don't wish to make it appear that I neglect this issue. In fact, if you do a search for "Speedo LZR" on our site, then you'll find a number of articles I did on the swimming costume issue. Alternatively, if you click on "Beijing 2008" in the tabs, you'll find the list of articles there.

That series looked specifically at the issue of rich vs. poor when it came to technology, so it is a topic I'm quite mindful of.

I guess my problem is this:

As soon as we start talking about all these issues (especially things like equal opportunity, poverty, life issues, then you are entering a minefield of enormous proportions! Because how can you possibly begin to compare one person's life situations to another's? For example, there is without doubt a young, 21-year 400m athlete in say Nigeria who is capable of running 46.5 seconds.

He is therefore the same as Pistorius. Except he has legs. But no coach, no money, no access to a gym, no support group, faces threats of violence, and can't afford to eat enough to feed himself and his family. He therefore trains hungry. Now, if we want "fair", then this athlete should receive a $1 million sponsorship and go to teh Olympic Games for overcoming his own "disabilities".

Another example is that I was born with weak lungs, and my muscles are not as strong as Lance Armstrong's. No amount of training is ever going to correct that - I'm just not good enough. But, since I have a problem with physiology, I can use drugs to correct the natural imbalance. That would be fair...

The examples are extreme, I admit, but the point is, you cannot begin to question fairness outside of what is controllable. And in this case, Pistorius is deriving an advantage from technology that is completely independent of life situation and other factors.

In fact, if you want to take this far, then Pistorius should not be allowed to compete because he is wealthy enough to afford carbon fibre limbs that cost him hundreds of thousands every year. Few others can, so that too is not fair.

I agree with you that "fair" is broad, but you can't begin to take this into account when evaluating fair competition. Everyone in the race stands on the start line as equals. If you start factoring in social, economic and psychological issues, then every second person has some entitlement to the Olympic Games and gold medals - I can think of five athletes I've trained who, barring one or two unfortunate incidents or social events, would have been Olympic athletes.


Anonymous said...

Actually Ross, I had a different defense of your "narrow" use of the term "fair".

The narrow context comes, not from you, but from the IAAF rule concerning ahtletes using devices potentially giving an unfair advantage. Social or financial factors are also important, but unrelated to this rule.

I don't know if you talked about it before, but it recently struck me that his slow starts would account for his faster finishes. In your comments above, you partly answered that it must be more than that. Can you elaborate on that just a little (or did you already?)

PS: Is it terrible if I propose to call the blades "cheaters"? -- that's what I think now everytime I see it.

Anonymous said...

I would like to add my input on this. My name is Arnaud Malherbe and I am the current record holder in the 400m for South Africa. I have retired from running in 2006.

Firstly, I think Oscar is a great guy and a spectacular athlete. However, there is no doubt in my mind that he does get aided by his Cheetahs. This is based a lot on the research published here by John and Ross, and also on my own observations as an elite 400m runner.

Without going into too much detail, I would like to note the following:
1. Anaerobic energy - my lactate threshold was measured to be somewhat higher than your average 400m runner, which enabled me to run at faster speeds for longer. Oscar gets the same advantage, but not through natural ability. Rather the energy output and momentum created by his "blades" allows him to actually lengthen his stride and speed up in the last 100m of the race, something that I couldn't do; something that Michael Johnson couldn't even do. That is because all of us start to "tie up". This is mostly due to lactic buildup in the achilles tendon area - something Oscar is not subject to.
2. Secondly, has anyone ever thought about measuring the strain on his heart while runnning, seeing as it does not have to pump blood down to his feet?
3. What about the weight of the blades, as opposed to legs? Surely the less weight you carry around the track, the faster you'll be?

I could go into a long discourse here, but do not have the space to say everything I would believe. The problem with the whole issue is that it is an emotional one and hence clouds people's common sense and judgement. I am glad to see some common sense and judgement being applied here.

Having said all that - surely if Oscar wants to compete with able bodied runners, he should do so by the same rules?

This means that he should never have been invited to compete in any Golden League meetings, such as Rome, as his times do not justify his inclusion. There are literally 100's of 400m runners in the world that should be included ahead of him. It also means that he should not be in a South African 4x400m relay team as there are 7 athletes ahead of him that deserve inclusion more.

Lastly, as mentioned in this article, inclusion in a relay team would put the team at a severe disadvantage, as it takes away any possible strategic considerations, having an athlete that can only run in the first leg.

Btw, even in the first leg, athletes cross the track in front of each other all the time and if you cannot readily sidestep or jump, and have carbon fibre blades to boot, that would cause a definite danger to yourself and other athletes.

Unknown said...

Why if the anaerobic component is such a big question, was it not tested? Even doing a simple lactate test with a finger stick would at least provide his mmol production of Lactate which then could be compared to other able bodied runners to estimate the amount of H+ ions produced? Surely this would have enlightened everyone to see how much of an advantage he enjoys at the sprint distance from the carbon blades.

adventurelisa said...

On target Arnaud. Great hearing you on David O'Sullivan's show yesterday evening. Very interesting comments about just how much distance 0.7s equates to and also really interesting to note how much training effort it takes to knock milliseconds off your times. Lisa

Migue said...


Anonymous said...

Silly question about the IAAF controlling the prosthetics:

Could they not hold onto them between meets? He could practice in his own version but use the ones held by them for actual races. He (or his sponsors) should be partially responsible for the storage fee. The IAAF then can be sure that what he races in are the same as what was previously test.

I realize it is too late now, but for future tests...

Ross Tucker and Jonathan Dugas said...

Hi again everyone

Once again, thanks a million for all the comments and questions. As usual, I'll post replies to each individually.

Can I ask, however, Arnaud, that you get in touch with me via email (sportsscientists@gmail.com). I know you were on the radio yesterday, and I really valued your comment here, and would love to chat. If you read this, please email me!

To get to the other questions:


You're quite right about the definition of "fair" according to the rule, good point.

As for the slow start, it's very different, if not impossible to say what the precise time loss is at the start, it's an unanswerable question. But if you consider Pistorius' 100m time (10.91), then the start CANNOT COST MORE THAN 1 sec. If it did, then we're implying that this guy is a 9.90 sec 100m runner. That's clearly not true. So the time loss is somewhere between 0 and 1 second. The rest is guess work. I'd say that 0.5 seconds, right in the middle, is the conservative number.

Assuming this, then his first half would come down by 0.5 seconds, and his time differential would also be reduced. Instead of running the first half 1.5 seconds slower, it would now be 1.0 seconds. Considering that Michael Johnson, and every other 400m athlete runs it completely the other way around (first half 2 seconds FASTER than the first), then he's still way out of the normal range.

Also, if you go right back to last year's post on Oscar's debut race in Rome, you'll see that I actually ignored the first 100m in one method of analysis - this takes care of the starting disadvantage. When one does this, then he still runs his final 300m in a "never seen before" pacing strategy. So no matter how you skin it, something is wrong.

Finally, I must make the point that we've never seen such a "slow" runner over 200m or 100m run so fast over 400m. I mentioned this yesterday as well, in another comment, but it's worth bearing in mind.

As for the name "cheaters/cheetahs", perhaps they should consider changing the name to Kangaroos - this would avoid confusion and be more descriptive, after all!


To Arnaud

I know you well, it's great to hear from you. I met you a number of years ago, though at that stage I was a small honours student in exercise physiology and not worthy of any kind of serious introduction! We shook hands, you raced, and I went on with my own business. So I know of you very well!

As I said earlier, it would be wonderful to speak to you, I think you can add a great deal, so please do drop me an email and we can make contact!

To Jen

Good question. The lactate WAS measured - it was NOT DIFFERENT, which would suggest that he's using similar anaerobic energy sources - this is option B in the post above. HOwever, a word of caution on lactate - it's a dicey measurement mostly because a finger prick is very different to what is actually happening in the muscle. If they could get that blood from the femoral vein, then it would be interesting! Of course, that's not possible.

There are other methods, one that measures something called the accumulated oxygen deficit. Whether this was done, I honestly don't know. If it was, then it DID NOT SUPPORT their argument, and that's why it has not been mentioned in the media. I suspect this is likely the case, though again, until the data is published (the big problem again) we'll never know.

Thanks for the comments, I'll deal with the latest breaking news in another post, and I'm sure more will come over the next few days.


Anonymous said...

Thanks for responding to my comment. And I agree with what you're saying.

However, I wasn't suggesting that sports should try and account for social/economic/psychological disadvantages . . . that would be impossible (as you say).

I was trying to suggest that an over-emphasis on the physiological factors of 'fairness' can lead people to forget about the broader systemic 'unfairness' of international sport.

I don't know whether it's fair or not to let this dude run . . .

But then again, I don't think 'whether it's fair or not' will even be the primary factor used to determine whether he can run or not . . .


nickgavey said...

This debate is very interesting. The discussion seems to centre on whether OP gains an advantage with Cheetahs in their current form. This approach to the debate would require a new round of litigation and extensive testing every time prosthetic technology was further developed. I’m really not sure that this is sustainable.
The issue for me is that prosthetics are fundamentally different from natural legs. The advantages that OP gains (no lower leg fatigue, no risk of lower leg injury, a theoretically longer stride) are distinct from his disadvantages (slower start, less balance). Rules in sport should be as simple as possible, and applicable to everyone. It seems absurd to have to perform a complex calculation about whether the advantages outweigh the disadvantages for every disabled athlete. It is also inequitable for disabled athletes that don’t have access to a multi-million dollar legal team.
Given how fast technology develops, it seems inevitable that prosthetics will develop to a point where able-bodied runners are unable to compete. I assume that we don’t want to incentivise athletes to chop off their limbs. So there are two choices: either ban prosthetics outright or only allow prosthetics to develop to a point where they compensate for a disabled runner’s lack of ability, but don’t provide an advantage. I’m not convinced that the second option is practical.

runtilyoudrop said...

If they dont confer any advantage then why cant able bodied athletes run in them?

Great stuff BTW

Barrld said...

Ross--I've followed your impecable analyses over the past 15 months with great interest and am certain that you are right about the "Cheetah advantage." One nagging question for me though relates to the money side of things. While certainly Nike can get some level of good press out of this, why not spend the $1 million on advertizing instead of on supporting Pistorius' claims? Does Nike do much better running clips of Kara Goucher than of Oscar, IMO. Further, what is the real market for the Cheetah? How many single or double amputees are there amongst the elite runners of the world? Where/how does the Cheetah manaufacturer cash in here?

Thanks, Tim

Ross Tucker and Jonathan Dugas said...

hi Tim

Thanks for the mail and considered questions. I'll do my best to reply to them below.

First, regarding the Nike angle, fair question, but I think you have to bear in mind that Pistorius transcends sport as a result of the profile they've created for him. When a company enters into an athlete-endorsement type contract, they value that deal in proportion to how many people the athlete will reach and connect with, not simpy the exposure they will gain.

Think for example of Tiger Woods, Rafael Nadal, David Beckham, Michael Jordan - they are icons, not simply sportsmen, and have become recognizable outside of their event. On the other hand, think of a sportsperson who is not quite as well known, or is in a sport that is not as well known, and you see the difference.

Kara Goucher, to use your example, is a great athlete, known in the USA and among track followers, but if you stopped 100 people in the street tomorrow, I'd bet that only 5 would know her. For Woods, 98 would probably know him (if not 100), Beckham 95, and Pistorius would be quite high as well - maybe 30 or 40. If you did that in South Africa, or Italy, I bet 90 out of 100 would know and love him.

So the point is that his image and focus transcends normal sporting boundaries, and that is very valuable. Add to that the fact that people not only know him, but love and admire him, and you have a very valuable case for sponsorship.

So, perhaps more than this, you have to bear in mind the associations that people will have with Pistorius. Typically, a sponsor is looking for positive associations - remember that the whole strategy of endorsement is that people aspire be like their "hero", or create mental associations between the hero and that product. So Lance Armstrong has sold millions of Trek bikes (if it's good enough for Lance, it's good enough for me), and guys like Jordan and LeBron James sell Nike basketball shoes because they are admired, respected, and have qualities associated with them that people then apply to the shoes they endorse.

The point is, the positive associations made by the consumer (you and I) are meant to rub off on the product. Now, how many athletes carry with them the same kind of positive association and affinity as Pistorius? once again, he transcends normal boundaries...he stands for courage, technology, speed, determination, spirit, all these positive things.

These days, there is a far greater emphasis on this personal kind of advertising and promotion. The days of simply putting ads out to get a share of people's attention are gone, mainly because there is so much "clutter" that we barely notice 90% of the ads we see! But when you see a man with no legs, and high-tech carbon fibre blades on a billboard, then that's powerful, it stops the traffic, so to speak, and is thus many times more valuable than a mass media campaign.

Then one final point I must make, which wraps this up, is that all companies are making a big push for the Olympic Games. The games in Beijing represent the year's biggest event, with potentially millions watching. How much more valuable is Nike's association if Pistorius runs? Remember that many more people will watch if he does...perhaps there are 100,000 people who will watch the 400m event if he is running it, given the hype (and had he qualified, there would have been a huge media campaign around it). Nike wants those people to watch the Games, as do his other sponsors.

One must not limit this to Nike alone - there is also Pirelli, Oakley, and at least three companies back here in South Africa who have put his image all over their products in the last few months. Pistorius has a dozen sponsors at last count. He is a goldmine, and the incentive to see him run in Beijing was enormous, hence the big effort to clear him.

As for Ossur, that is a little more complex, but nevertheless explainable. The thing about Ossur is that they are selling what is a niche product - few sales, high margins, but the key is to create a strong voice for the quality of their products. What better way than to produce artificial limbs that are so good they allow people to run against able-bodied athletes? For them, it's the same as if Toyota could go and make a car that was able to compete with the fastest Formula 1 cars, and still be cheap and look the same. Imagine how many people will buy it.

So for example, if I had asked you 12 months ago to name ONE company that manufacturers Prosthetic limbs, what would have said? But if I asked you now, you'd have an answer for me! That's worth millions, because they only have to sell a small number more of prosthetics to recover whatever cost they incur in sponsorship - their biggest costs will be research and development, sponsorship adds the icing.

Sorry for the long winded reply - I actually work in the sponsorship industry at the moment (between consulting to the University on the physiology side of things), so this area is of particular interest, and it's quite well know how endorsements and sponsorships are intended to work! But apologies for information overload!


Barrld said...

Thanks Ross, not too wordy and very insightful; I was not aware that Ossur made prosthetics for "normal" folks too. We haven't seen much in the way of Oscar Pistorius adds here in Los Angeles though I suspect that it's a matter of time if he indeed does run for the SA 4x400 relay team.

Best, Tim

Anonymous said...

I guess Richard Whitehead must also have a big advantage running marathons and ultras with his prosthetics.
Whats your take on this Ross?

Ross Tucker and Jonathan Dugas said...

Hi Wimpie

Fair question. The big difference is that Whitehead is an above the knee amputee, so he can't balance at all. He has no knee joint to provide stability or power, and when he runs, he has to kind of swing his legs around in a circular motion, because he can't accommodate the changes in leg length that are needed in order to run.

Pistorius is actually quite far below the knee, and so he has very little loss of stablity. Indeed, when he walks he doesn't struggle to balance nearly as much as you'd think - this is also the result of having learned to walk on prosthetics.

I'm not sure whether Whitehead lost his legs in an accident and had to relearn how to walk, or whether his story is similar, but it's not really relevant, because the lack of knees as a result of having such a high amputation makes his chances of competing with an advantage zero.


Anonymous said...

I've seen the 0-200m vs 200m-400m split difference. Obviously this guy has slow starts. I think what is more relevant is the 100-200m vs 300-400m split. I couldn't find this anywhere.

Ross Tucker and Jonathan Dugas said...

Hi Paul

Did that over a year ago now. If you go to the top of the page, and click on the "Topical News Stories" tab, you'll be taken to a page where, if you scroll down, you'll see a series of articles on Oscar Pistorius. One of those articles is titled "Pistorius' debut in Rome". That post looked at the pacing from 100m to 400m, and it takes care of the slow start.

I'm tired of people blaming Pistorius' split on the slow start - a 2 second difference does NOT come from a slow start. Unless you believe he actually loses 2 seconds at the start. If that were true, then he'd run the 100m in 8.8 seconds. Makes you wonder. So no, it's not the start, it's the blades.


Anonymous said...

"...Our results indicated that physiological function was largely similar, and virtually identical, respectively, between our amputee
and intact-limb subjects..."

Pistorius’ physiology (energy cost and fatigability) is generally similar (3.8% lower than elite distance athletes, 17% lower than 400m specialists) to that of intact-limb athletes, but his sprint running mechanics are markedly dissimilar.

At top speed, he exerts considerably less force on the ground in relation to his body weight than intact-limb runners, and his foot is in contact with the ground 14 percent longer on each sprinting step.

Pistorius spends 34 percent less time in the air between steps and takes 21 percent less time to wing his legs between steps.

Conclusion: running on modern, lower-limb sprinting prostheses appears to be physiologically similar, but mechanically different than running with intact limbs.

Source: "The fastest runner on artificial legs:different limbs, similar function?" - Journal Of Applied Anatomy (Published June 2009)

vikram said...

Hi Ross,

Excellent post once again.

Your post assumes that all runners who run 400m should consume an identical amount of energy (aerobic+anaerobic). Thus, when Pistorius uses less energy, he gets an advantage (presumably from the blades). Please can you elaborate more on this point - Do all elite able bodied athletes consume an identical amount of energy ? Is there no significant difference in the efficiency of elite athletes ?