Muscle cramp 'teasers'. . .

Apologies for the absence...and some muscle cramp 'teasers'

Ah, the joys of the University calendar! We must apologize for our somewhat lengthy absence - it has been 5 days since we last did a post, which I think is the longest break we've had since we began The Science of Sport in April earlier this year!

But we have good reason, for both Jonathan and I are both deep into marking and examination of undergraduate and post-graduate exams and theses at our respective universities. Though Jonathan and I both enjoy lecturing and find it very rewarding, when we reach mid to late-November, our disposition towards teaching changes somewhat, as hundreds of exam scripts and thesis work suddenly land on our desks for us to plough through! And funnily enough, the other work doesn't seem to realise it and let up!

So we do apologize for the break, but we're back now, hopefully with a bang, as we get stuck into a new series, this one on Muscle Cramps - Science and Fiction.

A follow on from fluids and dehydration

The series on muscle cramps is really an extension of our last series - Fluid Intake and Dehydration. In that series, we tried to explode some of the myths around drinking during exercise, describing how the prevalent "scientific" advice was in fact flawed (sadly, it's often fatally flawed). We looked at the claims and counter-claims and ultimately encouraged everyone to do the wise thing - listen to your body, and when it says you're thirsty, drink! But only then...don't let the fluid companies tell you that you're the only mammal too stupid to know when to drink by itself!

Introducing muscle cramps - some points to ponder

The muscle cramp story is similar, sadly. In South Africa, we have a host of companies who produce cures, preventative tablets, creams and liquids to help you avoid cramp. The premise, as was the case with fluids and dehydration, is that a cramp is caused by a depletion of some electrolyte - sodium, potassium, calcium or magnesium. All have been mentioned, and most often, it's sodium and magnesium that take the brunt of the blame.

We'll take a step by step journey through muscle cramps in the series. We'll tackle it in three parts:

1. What is a cramp? Very brief history and overview of what we know, and how we know it.
2. The electrolyte-dehydration-heat theory for muscle cramps
3. An alternative view - evaluating the gaps in the theory

So that is what you can look forward to (or with dread, as the case may be!) over the next week.

Until then, here are some issues to ponder:

• Despite the theory that muscle cramps are caused by electrolyte and fluid depletion, it has yet to be shown that people who cramp have lower electrolyte levels or are more dehydrated than those who do not. In fact, the studies have found that "Crampers" and "Non-crampers" have similar electrolyte and dehydration levels. Something wrong with that picture...

• If cramps are caused by electrolyte and fluid depletion, which muscles would be most likely to cramp? Would it not be ALL the muscles, because you're losing electrolytes and fluid through sweat, so then all the muscle groups should be vulnerable...yet for some reason, we cramp in the muscles we actually USE. Again, something out of place there.

(Some of you may already have a counter to these points, saying that what is happening in the muscle is not necessarily what is happening in the blood - we'll tackle that one for sure)

• And then finally, if you are reading this before heading off to bed, we hope that you don't experience the dreaded "Night cramp", which we're sure most of you have had at some stage. You wake up in the night, and feel a slight twinge, usually in the calf. Your first impulse is to point your toe, and when you do that, what happens? You may know that if you do this, you'll be writhing in agony instantly! Instead, what should you have done? The answer is you should stretch the muscle - stretching is the quickest way to get rid of cramp. Now, how do we explain that one according to a heat-electrolyte theory?

The answers to follow, so join us then!

Ross

Ryan Shay: Performance analysis suggests that he did not use doping products

Even as we continue to mourn the tragic and sudden death of Ryan Shay during the USA Men's Olympic Marathon Trials, there have been occasional murmurs that Shay's death was somehow related to the use of performance-enhancing drugs. Shay never had a positive test for any banned substance, although these days that means little as more and more doped athletes admit to past wrongs without ever having been caught. A toxicology report would do much to silence any critics, but all of us still await any news from the NYC medical examiner's office. Their report should be conclusive, but even in its absence, we're confident that based on an analysis of his performances, Ryan Shay was unlikely to be using performance-enhancing drugs.

No prior history

With each new Marion Jones, David Millar, and Erik Zabel that comes forward and admits to past doping, the fact that an athlete is the "most tested athlete in the history of sport” means less and less. Still, this small point falls in Ryan Shay's favor.

The absence of a "breakthrough" performance or season

One aspect of the model we use to understand doping in sport is that those athletes who start doping only later in their careers will produce "breakthrough" performances or seasons that indicate the introduction of drugs to their program. This phenomena has been seen before most notably with Barry Bonds, who at the age of 36 became the most productive offensive player in history. In track and field, Franke and Berendonk published the data of an East German female shot putter. This athlete trained drug-free for 14 years before using steroids, and over the next ten weeks her performance improved by 9%. (We reviewed this study here).

So it is an athlete's "breakthrough" that first should raise the alarm that something might be different. Typically, those athletes who are the best in their sport tend to be near the top at each successive level as they move through the junior and amateur and professional ranks. Adopting new (and legitimate) training techniques and indeed make a difference, but these translate generally into small improvements and not career building breakthroughs.

If we examine Ryan Shay's performances over his running career, we see that his 10,000 m time between the years of 2000-2002 (while he was running at Notre Dame) did not change by more than 1-2%, especially after the 2000 season. His "peak" performances for the Big East and NCAA Championships were always with 20-30 s of each other year in and year out, as show in the graph below:


Even after he graduated from Notre Dame in 2002, his 10,000 m performances did not change by very much in 2004, again shown on the graph. Had he used performance-enhancing drugs after leaving the NCAA competitive arena, we would have expected to see a significant improvement in his 10,000 m times during 2003-04, yet instead we see he ran similar times as all his prior performances, and in 2003 he finished 3rd in 14:06 at the USA 5km champs.

Later in 2002 Shay made his marathon debut at the La Salle Bank Chicago Marathon and posted a respectable 2:14:30. In a big city marathon like Chicago that put him way off the pace (he finished 15th), but showed he was on par with his American colleagues and perhaps with more experience he might improve that time by a few minutes. In fact Shat won the USA Men's Marathon champs in 2003, yet his record in the marathon is remarkably similar to his record in the 10,000 m in that he never really made a breakthrough performance:


Although it might appear that Shay's marathon times were coming down over his last three performances, in reality his slower times must be a function something else, for he ran his best time of 2:14:08 at the 2004 NYC Marathon, which was only 22 s faster than his debut at Chicago in 2002. So again his marathon performances do not exhibit any kind of "spike" or breakthrough that would suggest the use of performance-enhancing drugs. Had he suddenly starting using something, we could expect his marathon time to drop by 2-5%, which equates to a 2.5-6 min improvement. Instead, over the six marathons he ran Shay produced remarkably similar times.

What the performance data cannot tell us

These data unfortunately represent circumstantial evidence and cannot with 100% accuracy determine if Shay (or any athlete) did or did not use performance-enhancing drugs. However, what we can say here is that the data do not suggest he was taking anything, or perhaps even if he were then it certainly was not improving his performance and does not follow the other available evidence from Barry Bonds and our East German shot putter.

So for now we must continue to await the toxicology report from the NYC medical examiner's office. It will say what it will, although at this point the evidence from his performances suggests that he was not taking anything.

Sports Science as a marketing tool - Gatorade vs Enlyten

About three weeks ago, we concluded our series on "Dehydration and fluid intake during exercise". We tried to uncover many of the myths that surround fluid intake during exercise, and much of our focus was on some of the marketing claims made by sports drink companies, particularly Gatorade, who fund much of the research that has been done on the topic.

In the first post of the series, we examined how our paradigm has changed regarding dehydration and fluid - until about the 1980's, it was uncommon to find people even concerned about drinking during events. Yet something happened to stimulate massive public sentiment and perception that dehydration was to be avoided at all costs. That "something" was the growth of the sports drink industry, which recognized a need and created what was to become an "indispensable" product for athletes of all levels. We challenged that perception and the need as a created one, not backed up the valid science (for the circumstances, that is)

It's a controversial subject, for sure, because it touches on the 'purity' of science, the application of what might well be sound laboratory-based research to the public who purchase a product that is developed specifically based on that research. And we made the point that the research has become part of the marketing armoury. Scientists and science become the endorsing agents for the product, and the integrity of the science is compromised as a result.

An example of science-marketing

Well, as it turns out, we had a shining example of this two weeks ago, when the NFL saw a start of a court battle between Gatorade and a rival company, Enlyten, who have manufactured what are called Electrolyte Strips for use by athletes. The strips are designed to be placed inside the mouth, where they deliver sodium and potassium to the system more rapidly than when they are taken in through Gatorade.

We won't concern ourselves with the heavy scientific details just yet - views on electrolytes will come when we address the muscle cramp issue in a future series, and was already discussed fairly extenstively in our dehydration posts. But what transpired between Enlyten and Gatorade makes for an interesting follow up to our previous posts.

Enlyten were able to obtain an endorsement deal with the Buffalo Bills of the NFL - they were to become the "Official Electrolyte strip of the team (along with 8 other teams, it later emerges). However, Gatorade reacted rather strongly to this news - Gatorade, incidentally, is an official sponsor of the NFL in the category of "Sports drinks, bars and gels".

Category exclusivity in sports - an important concept

As an important aside, in the sponsorship industry, a company will almost always (understandably) insist of category exclusivity when entering into any kind of sponsorship relationship. This is a means to shut out potential competition and dilution of returns from that sponsorship. An obvious example of this is that you will never, for example, have an event or a team sponsored by both CitiBank and UBS. Similarly, in South Africa, we have two large mobile phone companies who are very aggressive in pursuing sponsorship as a marketing strategy, but will always insist that no other mobile company be given rights that may undermine theirs.

So when a "Commercial rights owner" (that is, the company that "owns" what is being sponsored) puts together it's sponsorship package, it will usually designate certain categories. You will for example have Official Vehicle suppliers, Official Financial Service Providers, and Official Airline, an Official Technology Partner and so on. Sometimes the lines get hazy, as in this particular instance.

A court battle ensues

When Gatorade heard that Enlyten was promoting itself as the Buffalo Bills' "Official Electrolyte Replacement", they sent a letter to the NFL saying that they already had the rights to that category. In response, Enlyten filed a lawsuit against Gatorade and its parent company PepsiCo, saying that the deal covered only sports drinks, bars and gels. It was also at this stage that Enlyten revealed that EIGHT other NFL teams had also enlisted Enlyten as their official "Electrolyte replacement".

The argument becomes one of semantics - Gatorade are effectively claiming that Enlyten's strip is nothing more than a compressed gel, which means it does contradict the exclusivity term in the Gatorade-NFL contract. Enlyten of course deny this. And ultimately, this is one for the lawyers to comb over the contracts. But what caught our eye was Gatorade's strategy in arguing its point, because they relied HEAVILY on the science which, to be blunt, is simply not there to support their claim.

The Gatorade statement - science as both marketing and legal rebuttal

"For decades, the NFL and its member clubs have selected Gatorade as the only electrolyte replacement choice for their athletes because it's proven to enhance performance and safety on the field. Gatorade is backed by years of hydration and sports nutrition research -- more than 100 peer reviewed, published research studies -- that reinforces our rightful place on the sidelines and in the locker room."

This is the statement that was released by Gatorade in response to Enlyten's claims. You will notice the heavy emphasis on the research and science. Note that this is besides the point - the issue here is not whether Enlyten does or does not work, or whether Gatorade's electrolytes are better than Enlyten's. The issue should be a legal one - simply, to determine what the terms of the Gatorade contract are. But the explicit invoking of the "100 papers" (which is a fabrication - call it stretching the truth) and the years of research is quite clearly Gatorade's white stallion, the saviour and means to maintain an enormous market dominance.

It is Gatorade who have funded an entire "Gatorade Sports Science Institute" and developed much of the field of sports science in the USA. And while the offshoot of this is arguably beneficial in many instances, it does leave one wondering just to what extent the "science" is compromised as a vehicle for marketing, and now, legal arguments?

More than any of the examples of advertising which also invoke the laboratory based research on which fluid replacement guidelines are based, this statement illustrates the importance of the science to Gatorade, but not for its product development, but as a tool for promotion and marketing. And make no mistake - that is fine, provided it's done responsibly. But the dogmatic adherence to the paradigm, and the resultant advice to athletes to drink and drink and drink, to avoid dehydration (which were covered in detail in previous posts, so hopefully this will not be taken out of context without support) has resulted in numerous deaths and does really illustrate just how the conflict of interest can lead one down a very slippery slope.

Looking into the future

As emphasized, this is merely an addition to the previous series, so if it seems unsubstantiated, please to look through the series on dehydration which you can find in the left column of the page. And looking forward, we'll tackle this electrolyte issue and the science behind both Enlyten and Gatorade's arguments in our series on muscle cramps, coming up shortly!

Ross

"Dear Olympic athletes: Please pick up your face mask on the way to the start line"

Or better still, how about "Sorry Olympic athletes, we are going to reschedule your event to another day, because the pollution in Beijing is so bad, it might be dangerous for you to compete"?

OK, we're making light of a potentially serious situation here, but there is growing concern over the potential problems posed by pollution in Beijing leading up to the Olympic Games next year.

Three months ago, we did a post describing some of the pollution problems the athletes may face in Beijing. In that post, we discussed which chemicals/pollutants posed the biggest problems, and what those problems might be for the elite runners. The athletes most at risk are, as one would expect, the endurance athletes who are put through prolonged exposure with high ventilatory rates. In fact, so concerned were the IOC chiefs that Jacques Rogge, head of the IOC, even suggested that certain competitions "might be postponed or delayed to another day."

In response to that threat (which has, admittedly, been known for some time), the Beijing Olympic Committee promised some drastic interventions. The allocated between $12 and $15 billion to the "clean Beijing's air" campaign, taking steps including shutting down of factories, and even banning cars with even and odd-numbered licence plates on alternate days! So has this attempt worked? Jump ahead three months.

Latest reports - it's not getting any better

In the latest developments, about two weeks ago, the day after an "Environmental forum" to reassure athletes that the air quality would be adequate, the pollution was so bad that flights had to be delayed due to poor visibility, children and elderly people were warned to stay indoors and the Weather Bureau issued a suggestion to "Wear a face mask if you go out"! (Story here). The pictures below show the situation in Beijing. In fact, visibility was down to 50m! Can you imagine the great TV coverage of the cycling, triathlon and marathon events?


But the Chinese say they have it under control

Still, Beijing are putting on their game-face, arguing that the pollution situation is under control. This despite the fact that recent reports from the United Nations suggest that the problem is getting worse, not better. Yet still, some of the bigger factories (major 'culprits' in the air quality situation) have decided to go back on an initial decision to slow down operations. The LOC have also apparently reversed a decision made earlier to close down factories for the duration of competition in next year's games. And the single biggest polluter, a company called Capital Steel, were initially due to relocate to another city before the Games, but will now continue operations throughout the year AND the Games.

These are not the responses of an LOC concerned about the growing pressure placed on them by the IOC to take action. In a speech two weeks ago, Rogge said that "Time may be running out. The conditions required for the athletes competing in endurance disciplines might not be met 100 per cent on a given day." This sentiment has been echoed by other IOC delegates, but for political reasons, there is a general reluctance to openly criticize the Beijing LOC. In fact, when Rogge addressed Chinese officials at the Environmental Forum in Beijing a few weeks ago, the concerns over the air quality were left out of the presented speech, but remained in the published version, circulated later.

Or perhaps the pressure from IOC is deemed less important than the pressure from the factories, companies and politicians, for whom relocation, reduced levels of operation and possible closure would have massive economic implications? I have little doubt that this pressure carries more weight than that of the IOC. And given the fact that there is no real evidence to know what constitutes "SAFE" when it comes to elite athletes competing at high intensity, the Beijing LOC have an escape clause, because all they need to do is meet some "acceptable limits" decided upon based on studies of general health. It's not difficult to see the difference between long term impact on health and the short term impact on performance and acute health problems, but this fact doesn't seem to have entered into the LOC's thinking.

What about the athletes? Pollution plus heat equals a major challenge

And forget the poor athletes who have to run in the conditions. Kenenisa Bekele and Meseret Defar, Ethiopia's long distance champions, recently described conditions as "disgusting", and I know that many athletes are dreading the time they have to spend in Beijing.

It is perhaps the single biggest concern for athletes leading up to Beijing. Not only will the high temperatures and humidity pose huge challenges, but the pollution is likely to be a real factor. One could argue that it's the same for everyone, I suppose, but it will be interesting to see how the different nations plan to overcome this problem.

On the Sports Science side of things, Australia and Great Britian have already announced that they will take steps to limit exposure of their athletes. Great Britian's swimmers will prepare in Osaka, Japan, arriving only a day or two before their events.

As usual, Australia have begun meticulous preparations, and will have an asthma specialist on their medical team, have investigated the possibility of air filters in the Olympic Village, and will also delay arrival in Beijing for as long as possible. They also reported last week that all athletes will be fitted with contact lenses because "it is difficult for the atheltes to wear sunglasses because of the haze, humidity and pollution". So they tested all atheltes and will supply special contact lenses with a UV filter! In South Africa, I don't think we even know whether atheltes need glasses or not! I must confess this contact lens theory seems a little bizarre to me, and I'm sure some of the sponsors (Oakley, for example) won't enjoy that, but that's what they feel will help.

I have little doubt that many other nations, including South Africa will do the same, regarding preparation and arrival in Beijing. I'm interested to see what the USA does in this regard.

The final problem - heat. Does it favour the Africans?

The final problem, is of course the heat. This is something we'll devote a great deal of time to in the future, as it's a big area of interest for us both. But as a teaser, I will say that the African runners are not as comfortable as everyone thinks when it comes to running in the heat. The reason is that the Africans, though well adapted to the heat during the summer, are going to be arriving in Beijing having come out of the cooler part of the African year. This year, the typical day temperatures in Kenya and Ethiopia in July and August were in the low 20's, which is not hot enough to adapt to the heat. One must remember that if you are going to be training at altitude, it is generally cooler than at sea-level. This combined with the season means that many African athletes will be going into Beijing unaccustomed to the heat.

So in fact, if I had to guess, I would say that the likely marathon winner will be a Korean, Japanese, or better still, a Kenyan who has been based in the Far East for a long period. If I were the Kenyan or Ethiopian coaches, I'd be relocating my athletes to Japan for about 2 months leading up the Games, and definitely picking atheltes who have demonstrated ability to tolerate high humidities in particular. Altitude training is going to be far less important than heat adaptation. We saw this in Osaka this year, and Beijing will be even worse...

Ross

Click here to read our initial account of air pollution, including some of the physiological problems it poses for the atheltes