Fatigue Series Part 4: Exercise in the Heat

Exercise in the heat: Predicting the physiological future - African runners outperform white runners in the heat

We're back with Part 4 (or is it 5 or 6? I've lost count!) of our Series on Fatigue during exercise. In our last post, we looked at exercise in the heat, and found that:

• Laboratory research shows that human beings will stop exercise when their body temperature rises to a certain level. That level is of course dependent on the athlete's motivational levels, though interestingly, not necessarily on their training status or performance.
• We also saw that the science has shown that when the body temperature rises to reach about 40 degrees, the brain actually activates less muscle than a "cooler" brain, and that there is evidence for reduced arousal and motivation.

So, the hypothesis, based on these constant workload studies, is that the heat affects performance because:

A high body temperature DIRECTLY inhibits the ability of the brain to activate muscle.
Therefore, exercise stops (because in these studies, remember, slowing down is not an option)

What happens when the athlete CAN slow down? Self-paced exercise

Today we turn our attention to the case where athletes can slow down - this is arguably more representative of what you will see in Beijing later this year, since any athlete can, at any stage, choose to drop off the pace. Of course, they lose their medal chance this way, but it's a much more applicable form of testing.


And to understand this, we look a few studies. We'll do it in a couple of posts, because otherwise the length would become enormous. So today, we consider one study, with more to come in the next few days.

In 2000, a study by Tatterson (J Sci Med Sport) found that cyclists slowed down soon after they started a 30-minute performance trial in hot, but not cold conditions. What was significant is that their body temperatures were not higher in the hot than in the cold when they slowed down. Obvious, yes, but quite contrary to the theory that your brain stops activating muscle AFTER your body temperature hits the "threshold". They didn't measure any index of muscle activation, however, but it was a crucial observation that something else (and not direct body temperature) was playing a role in the heat.

African runners in the heat - anticipatory regulation thanks to their smaller size?

Then, a study done by Frank Marino while he visited Cape Town a few years back, was one of the first to use the words "anticipatory", because his finding (discussed below) found differences in the pacing strategy of African runners compared to white runners in hot conditions. So the conclusion is that something is happening BEFORE the body temperature rises, slowing the runner down so that they don't overheat.


And this is obvious. Think for a moment about when you go and train on a very hot day. You do not simply go out and run or cycle at your normal pace until suddenly, overcome with a sensation of hyperthermia, you slow down! Rather, your entire approach to the session is changed and you slow down LONG BEFORE you ever get hot in the first place! Within the first few strides, you're probably already going slower. So this is one of those examples we spoke about a long time ago - intuitively, we know what happens.


The question is HOW? And also, we have to consider the prevailing expert opinion of the time. In this case, remember, the "textbook" knowledge says that exercise is impaired because the HOT BRAIN directly inhibits muscle activation after body temperatures are raised by exercise.

So, let's look at the study by Frank Marino. I'm sure he'll forgive my very rudimentary depiction of his methods below:





So he had 6 African and 6 white runners, quite well trained, doing a performance trial after a 30 minute steady run in either HOT (35 degree) or COOL (15 degree) conditions.


The starting hypotheses for this study, had you read the theories about exericse in the heat, would be:

• Performance would be impaired in the heat, so the runners would be slower during the 8km trial in the hot condition. This is fairly obvious.
• They'd slow down in the HOT trial because they'd be much hotter than in the cool trial - the high body temperature (and HOT brain) is failing to activate muscle, as we're told by other research.

This is what was found:

Graph of running speed (km/hr) against time for the 12 runners during 8km time-trial performances preceded by 30minutes run in hot and cold conditions

I've highlighted with a red circle one of the more significant findings - the white runners started the 8km trial much slower than the black runners did, from the first minute. Of course, both groups eventually slowed down in the heat compared to the cold (the black symbols on the graph), but it's this difference between black and white runners that should be of interest. So, why then, do the white runners start so much more slowly?

Option 1 is that they are already hot. They might be finishing the 30 minute steady run with higher body temperatures. That would agree with the theory that the hotter you are, the slower you go...

However, look at the graph below:

Graph of rectal temperatures during the course of the trials in hot and cold conditions

Again, I've highlighted the key point there - the black and white runners had THE SAME rectal temperature when they started the 8km run. And not only this, but the temperature was "only" 38.2 degrees, so they were way cooler than the supposed "limiting temperature".

Yet, for some reason, despite the fact that the black and white runners have the same temperature and are not in any danger, the white runners "chose" to START an 8km time-trial slower than the black runners. We can therefore dismiss Option 1 from above, and say that it's clearly not a case of a hot athlete slowing down! If it was this simple, with some "direct effect" on the athlete, then the slowing down would happen equally in the two groups. This is an amazing finding given the prevailing view that the heat impairs performance directly, I hope it strikes you that way too!

So what, then, is the reason? Well, that's of course difficult, if not impossible to PROVE (as we've seen recently courtesy the CAS, "proof" in science is not as easy to do as people think), but here's a theory from the Marino paper:

• The African runners were much smaller than the White runners - 59 kg compared to 77kg, to be exact. The white runners were taller, however, and had a larger body surface area.
• We know from previous research that a smaller runner produces less heat while running at the same speed as a larger one. That is, the total heat PRODUCTION is dependent on body mass, and smaller people produce less heat.
• Smaller runners also lose less heat, however, because they have a smaller body surface area to lose heat to environment.
• But the key is: These two factors don't exactly cancel one another out. The result is that even though they lose less heat, smaller runners are still able to lose more heat RELATIVE to heat production than larger runners. This has to do with the ratio their mass to body surface area - they may lose on surface area, but their lighter weight more than makes up for it.
• The net result of all this, is that smaller athletes have a reduced RATE OF HEAT STORAGE than bigger runners.
• Now, given this fact, if two runners are going along at the same speed, the smaller one will be storing less heat, and therefore his/her body temperature will be climbing slower than that of the big runner.
• Put differently, it means that if both athletes are concerned about how hot they are getting, then the bigger runner will have to slow down in order to prevent his heat storage from rising, which would ultimately increase his heat production.

Now, with all those facts on the table, the results start to offer an interesting theory:

The rate of heat storage is responsible for Anticipatory Regulation of exercise and pacing strategy in the heat

The theory is that the white runners, by virtue of their bigger size, have an increased rate of heat storage. (Note that this effect (the different pacing strategies, that is) is likely due to size - had the groups been matched for mass and height, the result might have been different - see the comments section to this post!)

The brain is "clever" enough to know that if the athletes starts their 8km time-trial at a fast pace, then their very high rate of heat storage is going to see their body temperature RISE very rapidly. They are in danger of reaching a core temperature of 40 degrees BEFORE the end of the time-trial (which they know is 8km long). Remember, at this temperature, the brain says "Enough" and exhaustion usually occurs (or soon after).

Therefore, the brain says "Whoa, back off a little!", long before the athlete overheats, and with the intention of making sure that they do not reach this limiting temperature before they are able to finish the trial - it would be a complete failure to do this, and reach the 6km mark by the time their brain says "enough". So instead, it REGULATES their performance IN ANTICIPATION of ever reaching that limit. That Anticipatory Regulation is achieved or mediated by the rate of heat storage, which is different from the very early stages of exercise.

On the other hand, the African runners, who are smaller, have no such problems. They thus maintain a higher speed, and a similar rate of heat storage, leading ultimately to an improved performance. Note, very importantly, that in the cold, this difference between black and white runners does not exist. Therefore, it's not a case that the white runners are just inferior to the black runners - it applies only in the heat, when the environmental temperatures bring this heat storage aspect into play.

Looking ahead

What this study does not do is measure anything related to brain function. Now, that's very difficult to do during dynamic exercise, and is often criticized, but we'll discuss a study tomorrow that looked at EMG activity (a measure of how much muscle is being activated by the brain) during trials in the hot and cold. This was the first study to find evidence for it. It was also a study I did for part of my PhD, though I'm not claiming anything here - it was be default, more than anything else!

So that's coming up in our next post - evidence of Anticipatory Regulation of Exercise Performance, along with a few more concepts to build on the ideas put forward here.

Join us then!

Ross

Pistorius verdict comments and responses

Great discussion on previous posts: Law + marketing trumps science

Having initially decided to wait on the "science" to be released before tackling the Pistorius decision further, we've had some really fantastic responses to our previous articles on the ruling by the CAS that Pistorius is eligible to run in the able-bodied Olympics, should he qualify.

I felt that so good were these comments that they warranted a separate post, since many do not read the comments (or can't via email subscriptions). So below are excerpts from those comments, which you can also read in their original form here. The comments are in blue italics, and my response to each is below, in regular text.

Before that, however, a summary of my take on the full CAS report (which I was going to do later, but thought it better to put in now).

Summary response to the CAS report

It's quite clear that the IAAF made many errors in the PROCESS, and these errors have cost them in the verdict. The report actually states that the IAAF "fell short of the standards" expected of it, which is quite damning criticism. However, the report makes little mention of the science, and frankly, that's what I'm interested in. There is some mention of the Houston testing showing that Pistorius has the same oxygen consumption as normal runners - the IAAF found it to be 25% lower, and so either someone is lying, or their equipment was broken, or they were testing VO2 in completely different circumstances. This third option is most likely, and I expect I'll be discussing it when I finally get to see that evidence.

The Houston report also mentions that Pistorius "fatigues normally". I can hardly wait to see that test - those who have been reading this blog over the last two weeks will recognize just how complex fatigue is. And with the greatest of respect to the biomechanists and engineers who were the experts in this case, "FATIGUE" takes on a very different meaning to an exercise physiologist. How was fatigue measured? What circumstances surrounding the test, and was it a performance test? All must be revealed.

Another great example is lactate - the IAAF, in their "wisdom", tried to measure lactate levels and VO2 during a 400m race to prove a "metabolic advantage". This kind of thinking is 20 years out of date, and lactate is a completely useless marker of what they were trying to do. I made this point last year, saying that lactate was irrelevant, and that they should be looking at the pacing strategy to understand fatigue - lactate was one of the myths that should have been dismissed from the start. Ultimately, they paid for a lack of physiology understanding in their process. They covered the biomechanics, yes, but the physiology was poor. I look forward to the "physiology" from Pistorius group, which I expect to be equally easy to dismiss.

I feel, based on these discussions and the report and the other feedback to date, that this is a case won on a "technicality", much like a criminal getting off based on improper evidence collection. The legal requirement for proper procedure is important, however, and I'm not condoning the IAAF's apparent errors. Perhaps the most blatant example of this IAAF "error" was the reported testimony of Dr Elio Locatelli, who said that the IAAF would not ban Pistorius from running in the 100m or 200m events, but only the 400m, where his advantage catches up with his disadvantage. Quite clearly, the ban should stand across all events, and this testimony is typical of the relatively weak case the IAAF apparently created.

However, as I state lower down in this post, I believe the NET advantage exists, and I believe it is a very large advantage (both performance and physiological). I base this opinion on the physiological facts and discussion that has taken place completely apart from the IAAF testing, since this opinion, and the reasons for it, were stated last year in June, long before the IAAF ever did testing to confirm those theories. The theories hold true today, as does the advantage, and I look forward to the day when someone else (not Pistorius, for I don't believe he is capable) will run the 400m event in 42 seconds using this technology.

Comments by JM:

Interesting: The matter was agreed upon to be a de novo investigation into the matter, yet, a lot of reliance was placed on the testimony and the findings of the previous testing done. Surely, to be technically correct, if a de novo investigation was done it would mean that a complete new test would be done under the auspices of the tribunal and THEN a decision would be made.

The burden of proof was deemed to be a "balance of probability". This means that the more probable viewpoint would be deemed to be the correct one. I cannot see, on the raw evidence of the science, how they could find Pistorius' version to be more probable.

Yes, agreed. The point that I've made in the last few days is that science holds one thing above all others to be fundamental, and that is discussion, peer-review and analysis of the work of others. Complete transparency is the critical component - the sanction of INDEPENDENT, new tests under the auspices of the tribunal, perhaps using the experts from both parties would have resolved this issue. I am not sure that the CAS allows such a process to be followed, however.

Instead, what has been done is an argument around the testing gathered by the IAAF. I guarantee that if the Pistorius "science" is ever released (someone said it would be, I'm sceptical), it will be easily challenged, for that is the nature of science. Regular readers of our blog will know how many issues in running and sport are "unprovable". Think of hydration, think of muscle cramps and salt supplements, think of running shoes and injury, running technique. These are topics that have been researched hundreds of times, and still, there is no consensus. Well, now we can add to that list the advantage of Pistorius.

When the opposing view is finally presented, it will be very easy to dismiss, because that's how science works often, and in this case, I have 100% confidence that the advantage exists.

However, the LAW says is not yet proven (see Norrie's comments later). The consolation I have, scientifically, is that some day, it will be proven, and it will take less than 42 seconds to prove the advantage exists and expose this particular case, because that's how long a more genetically gifted athlete (dare I say from West Africa) will take to run 400m.

An interesting point on the proceedings is that the experts went into a room to find out what they agreed upon and what not. According to the finding, the experts agreed that Pistorius had less up and down movement. They also agreed - and this I find interesting because that's not what I understood from this blog or from prof Bruggerman's report - that Pistorius fatigued at the same pace as ablebodied athletes running at sub-maximal speed.

That I don't get - it was shown that Pistorius has a faster second 200m than anybody else in history, but he supposedly fatigues at the same rate? How?

Your guess is as good as mine. In his testing in Cologne, Bruggemann did not directly measure any kind of fatigue at sub-maximal speeds. So this may be part of the yet-to-be-revealed science gathered by Pistorius. To my mind, the pacing data is the most conclusive and damning evidence to date (something I've said many times), and in the coming week, I'll take another look at it and discuss why. So how do you prove that he fatigues at the same rate? To an exercise physiologist (as opposed to a biomechanist or engineer, as the experts are), that question is in fact laughable - it can't be answered, because fatigue is enormously complex (as we're seeing in our series on it here at the moment!). Define fatigue, for example? If it's running speed, then it's obvious that he has an advantage, so they have looked at something else.

So again, what the LAWYERS have done is to ask the right question to suit their case, and the IAAF are painted into a corner. When I finally get to look at that science, it will be easy to dismiss this argument, I can assure you.

To me it seems that this thing came down to what most cases come down to - a discussion of the process. It looks, from the findings, that the IAAF slipped up in a big way at some points - thus leaving a gap that was forced open. It was the process that was adjudged to be unable to provide the probability, rather than the science, which is a great pity.

In my humble opinion a legal tribunal is the last place to adjudicate these kinds of scientific things, but that was the only option available. The tribunal made a legal decision - and on the face of it, it seems the correct one if one looks at what they say they were presented with.

Again, agreed (and our next poster also says pretty much the same thing). It boils down to a battle of perception, which was first manipulated in the mainstream media (go back to our posts on this topic last year to see that), and then the door was slammed open by some high-powered law. It was not science. Or perhaps, put in the words of our next poster from below, it was Law vs. Science. With marketing as the referee.

I also agree that the IAAF made some big errors, not only in the CAS hearing, but in the last 14 months. They were, after responsible for saying some pretty ridiculous things before the October testing and were caught napping when this situation presented itself. So the IAAF certainly have some hand in their own problem (a problem that is only going to grow moving forward). I agree with JM that it was a great pity, that the science should be soured by a technicality.

I still believe in that science, and let me make a very important point: My opinion that Pistorius has a large advantage is NOT based on the IAAF testing. If you go back to June last year, 4 months BEFORE that testing was already done, I wrote the reasons for the advantage based on physiological facts, and believe that they are still correct. It is that theory, borne out by Pistorius' pacing strategy and the IAAF result that form the basis to reject the fact that he does not have an advantage - he does, a large one, and it will become obvious in time.

The IAAF testing from October served merely to confirm what had been hypothesized (here on this site and elsewhere) leading up to it. But the theories, and the reasons for it, are the foundation - every testing result by the IAAF and from Pistorius' races so far confirms the hypothesis, which I stand by. In fact, I don't even think that the IAAF results are the most important pieces of evidence in this case. They confirmed the theory, and to now see those results "greyed" by the law is a pity.

Comment by Norrie:

Initially I was floored by the CAS decision, but upon reading the judgment and documents - it is clear that:
IAAF looked only at one rule - which I believe to be a mistake.
That the protocol given to the testing team in Cologne was flawed in that it looked to prove advantages and not overall advantage in performance (all athletes have strengths and weaknesses with the overall performance being the time - Oscars slow start outweighs performance at 100 and 200 - but 400M? and in future 800 to 1500?)

I agree in principle, but this is a classic example of how marketing/promotion and clever legal work has twisted the realms of what is possible. How do you measure PERFORMANCE advantage in this case? How is it even possible to answer the question? It's not, because the only study that would PROVE it is one where you made someone run in normal legs, then amputated, and had them run in prosthetics!

Obviously, that's not possible, and so the IAAF had only one option - evaluate the physiology and the mechanics of Pistorius' running. They did it, and found huge differences. So large, in fact, that one can say that Pistorius is a completely different proposition from any other runner. His advantages, physiologically, were huge. His pacing strategy (not the IAAF finding, but mine), suggest massive performance advantages, but can't prove them, because the "burden of proof" cannot be met by science in this case, as it was set out by the CAS.

But yes, the IAAF got killed in court because clever lawyers asked the right question: "Can you prove performance advantage?" The answer is no, and it shows that the trick is to ask the right question as I said in yesterday's post.

The burden of proof lay with the IAAF and the measure was 'balance of probability' In effect there was little need for Oscar to prove his disadvanatge only to create question over the method of appraisal- It was law versus Science

I am amazed that the burden lay with the IAAF. It should have been with Pistorius to prove that his legs did NOT provide an advantage. I can think of few sports where the governing body must prove that some piece of equipment is not advantageous before banning it. If I took to the tennis court with some new device, I'd have to first prove to the authorities that my device was not altering my ability unreasonably. I believe the burden should have lay with the person wishing to gain special permission to use the blades. This is yet another example of how poor control of this situation allowed the door to be left ajar and smashed open by clever lawyers. We wrote over a year ago that the burden should always have been on Pistorius.

But back to Oscar (which this case should never have been about - it should have been the principles and future practicailites as well)

The judgement refers to him as a 100m 200m and 400m athlete - so presumably he is restricted to this (although my feeling is 1000m will prove to be his optimum distance - lets see what you get Ross - so 800m 1500 in competitions)

Yes, the case should always have been about the future implications and not Pistorius. This is where the marketing and media bandwagon that Pistorius had behind him should take a bow and the credit, because they positioned this as a case of Me vs Them, when it never was. This too, was written on this blog over a year ago.

As for Pistorius' best distance - the 800m would be better than the 400m, if he was prepared to train for it. I think that right now, he probably couldn't run a good 800m, simply from lack of training and conditioning. But given the right training, a sub-1:40 800m time is easily on the cards. Of course, this will never happen, because then the fraud would be obvious and the ban would be easily implemented.

In fact, I don't think that Pistorius will ever run an 800m competitively, because it would expose him and he wouldn't put in the necessary training. However, my hope is that someone else does - perhaps in ten years' time, someone will do that, and expose the true size of the advantage.

The immediate future sees a possible 400 relay, with a rolling start over 20m! - that puts a different spin on things - Running in the second lap, with the protection of 100m plus of lanes in which momentum will be maximised could carve seconds from his lap time!

Yes, excellent point. Of course, that's not conclusive of anything - his team will merely point out what a fabulous athlete he is and how good he would be if he didn't have his problems with balance at the start. The SA team (if he's in it), might consider giving him the full 20 m head start to make the most of his advantage in the final 300m of the race. But it's his pacing strategy that I look forward to analysing, as well as the science when it eventually is presented.

Until then, though hopefully it won't be long, I wait for 42 seconds of proof.

Thanks for the comments and discussion, which has been excellent - I was reading a local newspaper this morning, and the editors of that paper would be well advised to listen to thoughtful, objective discussion such as yours.

Ross

Pistorius cleared Part 2

Views from the running industry: Logic and implications

Yesterday (or earlier today), depending on your location, we brought a preliminary response to the CAS ruling that will see the introduction of technology into running over the next 50 years (you can read this below, if you are receiving this as an email). The ruling applies specifically to Oscar Pistorius, but has far-reaching ramifications, many of which are not even apparent today. One thing I feel sure of is that the day, 16 May, will be looked back on with a great deal of regret some day, because it is a mistake for the sport.

For today, however, I thought I'd rather refer to a couple of discussion threads on the topic, from within the running community. They give some diverse insight and opinion. I've also posted in two of the discussion pages, so my opinion is clear there (some repetition between the two), and it means I don't have to double post. Those discussions:

• Lets Run thread on the verdict (my post on page 2)
• Lets Run thread on Pistorius' potential in the 800m event (huge question - see some of my thoughts below)
• Runners World SA discussion (my post on Page 2)
• Then, the other site worth visiting for a well-rounded discussion is "Optimal Training"
  

Before you jump to those (if you have time!), I do have two observations about these discussions that sum up pretty much what is in those discussions and should be read first:

1. The running community looks at this differently, and "knows"

First, it's interesting to me that within these running "communities", the prevailing opinion is that he has an advantage, whereas currently, most people outside of the sport say he does not. I feel that over time, that perception will change (wait for it to become obvious that the advantage exists, and then everyone will "see the light"), but it's nevertheless interesting that informed runners see the advantage logically and clearly, while those outside, or with any other incentive (other than the sport of running, that is), fail to recognize it.

I wonder if something in our experience as runners (particularly if you've been semi- or fully-competitive) provides this? Some will argue that it's false perception, but certainly, the logic of the arguments, and the relative lack of emotion, is completely different from what you see in general discussions, and it interests me that the opinion could be so polarized, with runners, in my opinion, knowing the truth.

2. The range of implications- endless, worrying and very likely

A. Deliberate amputations

Secondly, you'll see in these discussions many people's response is that the logical consequence of this decision is that people will cut their legs off and try to gain an advantage. I don't think this is beyond the realms of possibility - remember that a survey once found that 70% of elite athletes would take steroids to win gold medals, even if it was GUARANTEED to kill them by age 50! So it's not as extreme an option as people think!

However, this drastic approach of amputation would probably not work in adults, because an adult could not, in all likelihood, learn to run well enough on the blades to compete at a high level (though in the future, the technology may even allow this to happen, which is a huge concern, and should have been fundamental to the CAS decision).

B. Companies "scouting" for talent

A child, however, is another proposition. And I honestly do believe (you can save this post and refer back to it one day, whether I am right or wrong!), that this decision will inspire sports companies to go out and hunt for double amputee CHILDREN. Because a child, given the right equipment (which is expensive) and the right support (also costly) CAN learn to run on prosthetics. And so for that reason, I believe that the implications of this decision will not be felt now, but in a generation from now, when a West African child, or perhaps one from Jamaica or the USA, reaches the age of 20 and goes out and runs 40 seconds for 400m!

Consider for a moment the following fact: 95% of the world's fastest sprinters (100m, 200m and 400m) originate in West Africa. For some reason, we have all implicitly assumed that Oscar Pistorius has a "natural ability" to run 46 seconds. But why should this be? It's quite conceivable to me that there is a West African, Jamaican, and US runner, who would be capable of running 4 or 5 seconds FASTER than Pistorius if given the blades and the training at a young enough age!

It's for this reason that if I was a rep at Nike, Adidas, Mizuno, I'd be drawing up plans to get into West Africa right now, and find those people. In 12 years time, an 8-year old today, could win an Olympic title in every event from 400m upwards. The world records would stand at 41 seconds and 1:36 for 800m. That is perhaps the most realistic, though long-term implication.

C. Performance improvements in a laboratory: Technology and overnight speed.

A third possibility, of course, is that now that the technology has been introduced, someone has to regulate it! It's possible that over the next few months, the massive increase in funding (driven by the now real prospect of Pistorius running in able-bodied races), will see technology advance to the point where performance improves by 2 seconds, almost overnight! That destroys the spirit of sport, it compromises its integrity, and it most definitely makes a mockery of the "science" provided by Prof Hugh Herr, who himself doesn't want human legs back because because they will be archaic.

This prospect is the most likely short term implication. Now, the CAS should have considered this aspect in their decision, but based on the news releases, their decision was based around Pistorius and evidence for HIS advantages. There are many problems with that approach, as we discussed last week, but the pivotal issue in this whole trial is that Pistorius, through clever PR and marketing, managed to make this about himself. It never should have been - this was about technology in sport. And Pandora's box is now open, and how the IAAF, or any other sport, will regulate this, is beyond me. Drugs, cheating, fraud, and now this - sport is heading down a cul-de-sac that destroys the very integrity of the game.

To quote something I wrote on one of the discussion threads:

In marketing at University, they teach you all about managing people's perceptions through the media, through PR, and through clever use of facts. It's all about creating a mindset in people and the "positioning" your product in their minds in a certain way. And there's a great saying I recall: "What is the difference between a rat and a squirrel?" The answer is marketing. That is the power of positioning something in your mind - same "product", different perception.

And I thought of that yesterday, because one might ask "What is the difference between a ban and a clearance for Pistorius?". And the answer would be the same - it's marketing. It used science, yes. And it really irks me that science can be that "corrupt". But then just look at the supplement industry, which is, I am beginning to realise, looking more and more similar to this saga - big companies, big finances, big incentives, big secrecy. But it's marketing that won this battle, and in years to come, the sport will pay for that.

Looking forward: The week ahead

So, I believe it's a matter of time before the advantage becomes very obvious (and Prof Herr is proven correct - human legs will be "archaic"), but until then, we don't plan on dwelling on the verdict. However, I'm intrigued by a question posed by our friends over at LetsRun.com. They ask:

What could Pistorius run for 800m?

Next week, I'll do an analysis of Pistorius' pacing strategy and predict his 800m time.
Let's also say that we'll never see Pistorius run the 800m event, because then his advantage would be obvious. But it makes an interesting discussion point, so we'll look at that.

The whole pacing strategy issue, and the fact that Pistorius is the only athlete who has ever sped up in the second half of a 400m race was :

i) Conveniently overlooked at the CAS hearing, and
ii) Ignorantly dismissed by Pistorius' experts.

We'll look at this issue, because it is still, to this day, the single most damning evidence that he has an advantage.

That also links in nicely with our fatigue series, which we'll attack next week, with a post on exercise in the heat. So do join us then!

Ross

LATE EDIT TO THIS POST + ADDITION:

We have received some terrific feedback and discussion to this post (it can be found below under "Comments" if you're on the site, or if you are reading this as an email, click on the post title to be taken to the site). But for those on email, I thought I would post one comment in particular, and my response to it, which is an absolutely crucial piece of this puzzle.

Post: From Coach Dan:

Clearly, the decision was made due to the lack of scientific evidence that there is an advantage. In fact, if you read earlier sections of the decision, it notes that Dr. Bruggeman indicates the testing did not prove a competitive advantage

My response:

When you ask the question: Does the research prove that Pistorius has an advantage? This question is completely unanswerable, nobody on earth can say either yes or no to it. If they do, they are lying or ignorant.

The truth is that the only way to find an advantage is to do an experiment where an athlete runs in normal legs, then in prosthetics. Of course, that's impossible, and so the only approach for the scientist to this matter is to look for differences that imply advantage - to actually confirm advantage is impossible.

Now, this has been known since last year - we wrote it on this blog in June, and numerous others were saying the same thing - you CANNOT prove a performance advantage. But you can PROVE PHYSIOLOGICAL DIFFERENCE. And if you find that difference, then it is grounds for a ban.

The CAS have clearly seen it differently - thanks, in no small part, to 7 lawyers from New York. Therefore, if you ask the question: Is there a PHYSIOLOGICAL advantage?..the answer is YES. Is there a performance advantage? The answer is probably, but not 100% certain. And that is where marketing takes over, and three lawyers can be led to the incorrect verdict.

This case should always have been about the possibility that the technology can provide an advantage, or a difference. Yet miraculously, not a single "expert" (IAAF or otherwise) has recognized the absolutely crucial evidence that Pistorius does not slow down in the second half of the race. In fact, this is THE CRUCIAL finding, and it's been dismissed. This finding does show a PERFORMANCE ADVANTAGE.

So, the law says "Can you prove it?" Science says "Can you suggest it, based on hypotheses and physiological theory?" What Professor Bruggemann's study did was confirm the existing theories for an advantage - classic science, hypothesis - research - result - conclusion. But proof? That's a legal issue. And if you stop to think about it, little is actually 100% provable. Do violent TV games lead to more gun crime? Does watching TV lead to lower IQ? Many studies have looked at questions like these, and found very good associations, proving a link. But the trick is to ask the right question. When you have 7 top lawyers from New York, you know that they'll ask the right question, and that was done here.

Pistorius appeal: Science sold

Going, going, gone: Pistorius wins appeal, and Pandora's box is now open - good luck to athletics

I have no doubt that many have by now heard the news that Oscar Pistorius, the double-amputee sprinter from South Africa, has been cleared by the CAS to compete in able-bodied races against able-bodied runners. Little more than this has been released, so the grounds for the clearance are guess-work, other than to say that it was not a huge surprise, given the way that the case had developed. The sentiment before today's announcement was in fact that the verdict would favour him, because of the nature of the CAS process and the fact that three lawyers were required to evaluate two conflicting scientific arguments.

Perhaps most significantly, one of those scientific arguments, that of the IAAF, had been discussed and dissected for months before now, whereas the other, that of Pistorius, has still not be revealed to anyone. Quite what this shows is beyond us, and it will certainly be interesting to have a look at apply the same magnifying glass to them. I suspect the results will surprise.

Those who have followed this saga over the last 12 months will have little doubt as to our opinion on the science of Oscar Pistorius, and the size of his advantage. This LEGAL ruling does not change this - we are interested in the science, not the judicial reasons. And over the coming weeks, we hope that the "science" that is now being readily flaunted by those supporting this bid is revealed.

Peer-review, and obejctive, analysis of scientific research, is the fundamental basis on which science is built. The concept of "secret" research, done by scientists who are neither objective, nor independent, and certainly not neutral, is foreign to science. To have overturned a decision such as this one based on clandestine testing, which took place entirely in the absence of any independent expert, is a travesty of justice, more than it is a scientific proof of anything.

I eagerly await the first publication of those "scientific studies" which prove that there is no advantage. I do not believe that this research will be forthcoming, now that the dollar signs are in place and the incentive has been achieved by those who have much to gain from today's decision.

What I do believe is that this decision has changed the face of athletics, and a journey has now begun which we will ultimately all regret. So the day of May 16, 2008, will indeed go down in history (as Pistorius is quoted to have said), because it is the day that Pandora's box was opened.

Good luck to the IAAF, good luck to the sport, and good luck to all those spectators who wished for it to be opened. Whether it will take 4 months, 4 years, or perhaps 14 years, this day will one day be looked back on with a great deal of regret. The time will come where the effects are so obvious that even the most parochial and emotive supporter begins to recognize the problem, and what has been discussed will become unavoidable. Until then, the IAAF have to evaluate how to implement the far-reaching consequences of this decision. Shoulder replacement surgery and shot-put records of 25 m is the next step, followed by 42 second 400m times.

The next step is to wait on the scientific evidence, and just as Pistorius and his team of highly paid lawyers were able to criticize the IAAF-study, so too, his research should be exposed to the public. Indeed, this should have been the case from the outset, but nothing about this entire saga has been managed correctly. As soon as the scientific motivation is released, you can be sure we'll discuss it.

Until then, we leave you with a quote from the scientific expert, Hugh Herr, who defended Oscar Pistorius after performing his top-secret, unverified research. He advocates the introduction of this technology into the sport. This quote is no doubt familiar to many of your who are regular readers:

A bilateral amputee professor named Hugh Herr works here (at MIT). If anyone can predict what sports will look like in 2050, it's Herr, who lost his legs 26 years ago in a climbing accident. Herr wears robotic limbs with motorized ankles and insists he doesn't want his human legs back because soon they'll be archaic. "People have always though the human body is ideal", he says. "It's not".

Time will tell, but when the "expert" himself says that soon human legs will be "archaic", then good luck to the sport. May 16, 2008, and athletics' version of Pandora's box is wide open.

Ross

Athlete spotlight: Borzakovskiy and Radcliffe

Build-up to Beijing: Focus on Beijing preparations of Yuriy Borzakovskiy and Paula Radcliffe

A brief break from the fatigue series today, where we'll split the section on exercise in the heat up with some interesting articles we came across thanks to LetsRun.com (great site for running related news).

Yuriy Borzakovskiy - Olympic champion planning his defence

The first is an interview with Yuriy Borzakovskiy of Russia. He is the current Olympic 800m champion, and the 800m event, for those with an interest in the track and field races at this year's Games, is probably the most open event in the whole thing. There are probably ten men who, on their day, could win Gold. Last year, at the World Championships, for example, the top three were:

1. Alfred Kirwa Yego
2. Gary Reed
3. Yuriy Borzakovskiy

Only Borzakovskiy would have gone into the race a heavy favourite, though Yego and Reed are now realistic medal contenders in Beijing thanks to this result. But then so are about ten other men, including two young sensations: Abubaker Kaki Kamis of Sudan and David Rudisha of Kenya.

Kaki Kamis won the world indoor title earlier this year (in mighty imprssive fashion), while Rudisha, a young Kenyan, won in Doha on the weekend, running 1:44:36. And did we mention Saad Kamel, Bungei, Mulaudzi, Said-Guerni? The 800m event is so wide open that pre-World Championship favourites failed to even qualify for the finals! There are numerous reasons for this - the tactical nuances of the event, the unique physiological demands and difficulty of racing through two qualifying rounds, which many athletes are unaccustomed to, and don't seem to handle particularly well?

And then there is the psychology - in the article with Borzakovskiy, he alludes to the open nature of the event, insisting that there are no favourites for the Beijing title. But he does drop a few interesting hints at what it takes to win the title, including mention that Wilson Kipketer failed to win Gold in Athens because he was not "psychologically ready".

He also talks about how he is "in good psychological condition", and that he doesn't feel the need for any structured psychological intervention. Unfortunately, he doesn't elaborate on what that means, and he doesn't explain what he believes is the psychological "edge" that saw him win that gold medal, which would have been great insight.

Nevertheless, it's a great read, and really fascinating to see how he travels so extensively during the training phase. I count four different training camps in different locations, in addition to his home base, which is interesting, given that many of his rivals, particularly in Kenya, will find one single base during their build-ups.

The link again: Borzakovskiy article

Paula Radcliffe - Fear of failure and Beijing plans

The second and third articles concern Paula Radcliffe. Radcliffe is, obviously, one of the big names of the Olympics, perhaps more for her failures in Athens than her other magnificent achievements. The articles deal with the Athens Marathon and her now infamous DNF, which has been unfairly emphasized. She speaks in these articles about the burden of expectation and her fear of the same happening in Beijing.

I really do hope she can put this right in Beijing and win the title, though the challenges are numerous - apart from her rivals, there is the heat. Radcliffe is a bigger runner than many of the Japanese, Chinese and Kenyans she'll be racing against, and there is scientific evidence that size matters in the heat - bigger runners tend to fare worse in hot conditions (as we'll see in the next post on Fatigue and Exercise in the Heat).

The article alludes to the fact that Radcliffe is training in a humidity and heat chamber, which is of course vitally important in the build-up. Her injury is the other factor - a toe injury, which forced her out of the London Marathon. She seems to me to be the type of runner who needs and enjoys racing herself into better shape, and so that loss of a race may be substantial. She mentions in the articles that it's not a major concern for her.

Good reads, both articles, which you can find here:

Radlcliffe article 1
Radcliffe article 2

Looking ahead - picking up fatigue

Looking forward now, the next post on fatigue is on the way (as soon as time allows it!), and it will look again at exercise in the heat. This time, however, we'll concentrate on the regulation of performance (as opposed to the heat limitation of exercise, as we did yesterday) in the heat, with special focus on Beijing.

Join us then!

Ross

Fatigue Series: Part III - Exercise in the heat

Exercise in the heat: The "off-switch," the limiting temperature, and the Beijing Olympics

We're back with more on fatigue, and as promised, the strategy we'll adopt over the next few posts is to look at fatigue in very specific situations. These situations, often the intervention controlled by the scientists, offer a glimpse into how exercise performance is either limited or regulated, and help us understand how performance might be improved (by working backwards from the regulation or limit).

As we discussed in our last post, studies can look at exercise performance as being "limited" by some failure, or as a "regulated" process, where the body aims to maintain homeostasis by regulating what we've defined as the pacing strategy.

In today's post, we look at exercise in the heat. This is especially topical this year, because the Beijing Olympics promises to bring the influence of heat and humidity into the public eye in a big way. Elite athletes the world over are preparing for the heat by using special chambers to replicate the likely Beijing conditions, and it's also one of the reasons we discussed a few weeks ago that the Kenyan runners, the big favourites for the marathon, might have their work cut out, given the "levelling effect" that the heat can have.

Exercise in the heat: What ultimately limits performance?

We start our investigation of the heat by asking this question, which represents, of course, the "limitations" model for exercise. This is a crucial question, however, because if we want to know how exercise is regulated, it's important to recognize that it is ultimately limited by some variable.

The early theory - blood supply limitations

And until about 30 years ago, the early understanding of exercise in the heat is that it was limited because the body did not have enough blood to get to both the muscles and the skin, where it was needed for cooling. The result of this limited blood supply was that the muscles were deprived of oxygen, became anaerobic, and exercise stopped. Alternatively, the blood pressure was challenged to the point where exercise was completely impossible. This would, according to our discussion of constant workload vs. self-paced exercise, represent the point at which the "bridge breaks", or the light goes off!

However, in 1979, a scientist called Nadel published a study showing that blood flow was in fact not limiting during exercise in hot conditions. This was followed by studies in the 1990's from Denmark (where a lot of heat research comes from) which showed the same thing - there may be a challenge to blood supply during exercise in the heat, but the body is more than capable of meeting it in healthy individuals. And so that theory was disproven.

A clue to the limit - mental confusion

But around the same time, it was recognized that when these athletes were exercising in the laboratory, there came a point at which they actually developed mental symptoms - lack of co-ordination, dizziness, confusion and loss of ability to control their limbs! This led scientists to speculate that in fact, the limit to exercise in the heat was central, involving the brain. The speculation at the time, as far back as 1987 by a Canadian pair (Bruck and Olschiewski), was that a high body temperature affected brain function and the drive to exercise.

The famous video, shown at the end of this post, captures this situation - it is Gabrielle Andersen, staggering and swaying through the Olympic stadium in Los Angeles, typifying the human response observed in the research subjects at the point of exhaustion during exercise in the heat - paralysis on one side of the body, confusion, loss of co-ordination and balance.

Limiting body temperature - the "off-switch"

Subsequent work showed this "central fatigue hypothesis" to be a distinct possibility. It turned out that animals and humans all stopped exercise at a very distinct body temperature.

For example, in cheetahs (running on treadmills, believe it or not!), it was noticed as far back as 1973, that at a particular point, the animals displayed very strange behaviour - they simply "gave up" running and lay down! In the words of the authors (Taylor and Rowntree):

“…the cheetahs refused to run… They would simply turn over with their feet in the air and slide on the tread(mill) surface".

Later, it became possible to actually measure the body temperature of animals and humans during exercise (I can't imagine it's very easy to measure the body temperature of a Cheetah during running! Rats and goats, perhaps, are easier propositions!). It was found that all animals seemed to have a very narrow range of body temperatures at which they would stop exercise. For example, beagles stopped at body temperatures of about 42 degrees, antelope 42 degrees, and goats 43 degrees. Rats, the most tested of all, were found to stop at about 41 degrees celsius.

Human beings - a thermal limit to exercise and a proposed mechanism

Then came humans. And perhaps not surprisingly, research found that humans tended to stop at a body temperature of about 40 degrees celsius. What was most interesting is that this temperature was consistent regardless of pre-cooling, the rate of heat storage, and the degree of heat adaptation. In other words, it seemed that humans have this "off-switch" at 40 degrees celsius, irrespective of the external intervention. The only thing that changed was the time it took to get there - for example, a person who is well adapted to the heat is able to sweat more, lose more heat and therefore takes much longer to reach this limit than someone who goes straight into a hot environment. But they still stop at around the same temperature, according to this lab research.

Remember that this is found when humans exercise in a laboratory at a constant workload until they themselves decided "enough is enough" and choose to stop. When given a little more motivation (like when an Olympic gold medal is on the line, or that 10km PB you've been training for), it's likely that you'll get this body temperature up to 41 degrees, but beyond that, it seems that exercise is very nearly impossible, at least in the absence of some pathology or abnormal response.

Remember also that heat stroke, which is a very serious medical condition, happens at a temperature of 42 degrees, so the limit to voluntary exercise happens well before this level is attained. That of course raises the interesting question of why heatstroke happens - a malfunction of the "off-switch", perhaps? Or a failure of the signal to actually reach the brain to stop exercise? It's a difficult one, for which there are theories, and we'll cover them at some stage.

The mechanism - reduced muscle activation and arousal levels

So once this was discovered, science began looking for the mechanism, the HOW of the "off-switch". Because the thinking was that the central drive (from the brain) was the culprit, it made sense to look at brain function for clues, and that's exactly what the Danish researchers did. So, in a series of studies, cyclists were made to ride in the heat at a fixed workload until exhaustion, and then various measurements were made of brain function and muscle function. There were two key findings:

1. At very high (40 degrees) body temperatures, immediately after the athletes had become exhausted, they found that the activation of muscle by the brain was actually LOWER than when the body temperature was only 38 degrees. The graph below shows the EMG activity in the quadriceps muscles after exercise in the hot and cool conditions. It's quite clear that the EMG, which is a measure of activation of muscle, is lower when the body is hot. So that gives an indication of why the cyclists were no longer able to push out the required force - their brain simply prevented them from activating the required amount of muscle.
2. There was evidence of reduced arousal/motivation levels once the body temperature rose. In fact, what was found is that there was a very good correlation between a rise in body temperature and a reduction in arousal. Motivation or arousal, incidentally, was measured using EEG and the ratio of certain brain waves which are known to indicate this parameter. The key point here is that as the body temperature gets higher, the motivation declines, and this in turn is responsible for a rise in the perception of effort. They therefore found a good correlation between RPE and a rise in body temperature, though of course, correlations are often a slightly misleading. The key is: Increased body temperature = decreased motivation/arousal = increased effort perception.
   

The problem with this research: What happens before the "off-switch" is reached?

Again, the key question one should be asking is whether this solid science is actually relevant to what you are going to witness in Beijing later this year? Because in Beijing, the world's best atheltes will line up, highly motivated, take part in a race, where they can speed up or slow down, depending on the innumerable factors that go into racing strategy.

The studies have shown that when athletes go at a fixed pace until they are exhausted, they'll stop when their body temperature hits about 40 degrees. Perhaps, given the incentive of Olympic Gold, that temperature will be higher. And perhaps, when they push themselves hard enough for the rewards that are on offer in Beijing, they'll be able to raise their body temperatures so high that they end up looking like the famous Gabrielle Andersen from the 1984 Olympic Games marathon (see video below).

But, realistically, you know that this doesn't happen, because Olympic competition is not a fixed workload trial to exhaustion in a lab, and the athlete is able to slow down if they wish. And so what you will see in Beijing is athletes dropping off the lead pace after only 7 km of a 10km race, and then you have to wonder: Are they hot, or is something else in play? And you should be asking: What happens when the body temperature is 39 degrees, and there are still 20 km of the marathon left to run? Does the brain allow the athlete to just run and run until it the body temperature hits 40 degrees, and the athlete stops? Of course, you suspect the answer is no.

So the "limitations" theory for exercise in the heat, while proven in the lab, fails to explain what you'll see in Beijing later this year, and will have experienced in your own training, many times.

And that's what we'll cover in our next post. Join us then!

Ross