Mitchell Report due today

Former Senator's report promises to be a 'huge story'

Eighteen months ago, former US Senator George Mitchell launched a probe into steroid use in baseball. The probe is the result of an unprecedented shake-up in Major League Baseball that started as far back as 1998, when reporters noticed a tub of androstenedione in aspiring home run champ Mark McGwire's locker. McGwire went on to hit 70 homers that season, smashing the former record of 61. According to San Francisco Chronicle reporters Mark Fainaru-Wada and Lance Williams in their book Game of Shadows, this helped spur Barry Bonds to begin using steroids in pursuit of McGwire's new record (and fame).

For the next few years things were relatively quiet in baseball, until all hell broke loose in September 2003 when Victor Conte's BALCO offices were raided. We all know the resulting shockwaves that went through sports, and we still feel it---in October Marion Jones finally confessed to using drugs, and just this week she was finally stripped of her Sydney 2000 medals.

In March 2005 congress invited a number of players, former players, and baseball executives to a hearing to discuss drug use in their sport. Most parties decline, however, leading congress to issue subpoenas, which were fought hard by MLB. Former players like McGwire and Jose Canseco were dragged in front of congress for eleven hours, although most refused to provide any meaningful information. Said McGwire, "My lawyers have advised me that I cannot answer these questions without jeopardizing my friends, my family or myself. I intend to follow their advice." That was unfortunate as McGwire (and others) had a golden opportunity to come clean. He had already retired, and all that was on the line was his records, which were illegitimate anyway.

Fast forward another year to March 2006, when the former Senator Mitchell agrees to lead an investigation into alleged steroid use by players working with Conte's BALCO. However baseball commissioner Bud Selig makes it known that Mitchell has the authority to expand the investigation as he sees fit.

But don't we know they are all juicing anyway?

And now, 1.5 years later, the Mitchell's findings and report will be released. . .but will it just tell us what we already know? We have a feeling that most of The Science of Sport's readers will agree that MLB has an endemic drug problem. Since 2003 and the BALCO bust numerous names have been named, and even since MLB's (weak) testing policy was instituted in 2003 a few players have had multiple violations. But Mitchell's report should go deeper than and perhaps outline for us the depth of the use. To date no big names have tested positive, and sources today promise that Mitchell's work will expose just how high up the drug use goes. Stay tuned for our analysis of the findings as we will be glued to the media outlets and waiting for the release.

Preview of other forthcoming attractions

Apart from the Mitchell Report, there are a few other big "events" on the horizon. First, speaking of release dates, Part III of our series on Running Economy will be "released" tomorrow here at The Science of Sport. We plan to cover training effects on running economy with some practical applications. We are sure all the media outlets will pick it up. . .!

And then also due out tomorrow is the IAAF's report on Oscar Pistorius, which we will analyze in great depth. But there is a preview of the tests that were done and our initial impressions of them above. Those who've been with us since June will have read the controversy regarding Oscar Pistorius, which culminated in a series of tests to determine whether his carbon fibre blades do give him an advantage. Given the tests that they performed, which basically amounted to science's equivalent of a fishing expedition, it might make for interesting dicussion! We'll be sure to bring you as much insight as possible!

In the mean time, check out this complete time line of drug use in baseball since 1998 to refresh your memory and fill in some blanks.

Interesting news from the marathon

The sub 2-hour marathon, London 2008, and Paula gets hot

We're bang in the middle of our series on Running Economy, but thought that for today, we'd take a break from that series and turn our attention to a few interesting news stories that are coming out of the world of marathon running.

The Sub-2 hour marathon: Debate re-opened

The first is a discussion about whether a sub-2:00 marathon will ever be run? This is a topic that hit headlines in September this year, when Haile Gebrselassie broke Paul Tergat's world record in the marathon. The margin? 29 seconds, taking the time down from 2:04:55 (run by Tergat four years before) to 2:04:26. We covered the race, and Geb's splits and pacing in a couple of articles at the time.

As tends to happen whenever a barrier is broken, everyone started talking about the prospects of the sub 2-hour marathon. Even Gebrselassie made his predictions, though he was a little more circumspect, suggesting instead that he would run 2:03 some day. But a lot of people were looking even further into the distance, at the 2-hour barrier. And a recent report from the Herald paper quotes Dave Bedford, London Marathon organizer, as predicting that the 2:02 will be run by 2015, and a sub-2 hour time will come in 20 years!

The problem is that even a basic analysis of the world record in the last twenty to thirty years suggests that this talk is likely a touch premature! For example, in the last 22 years, the marathon record has come down by just under 3 minutes, from 2:07:12 in 1985 (Carlos Lopes) to the current 2:04:26. So for Bedford to be correct, we need the next 22 years to yield 50% more than this - 4:30! But even more than this, since Ronaldo da Costa broke Dinsamo's 10-year old record in 1998, we've moved into an era where the record is coming down by seconds, not minutes, making this highly unlikely!

In otherwords, it's difficult to see how anyone is going to knock more than 30 seconds off this time. When Gebrselassie ran his 2:04:26, we all marvelled at how massively he 'shattered' the record, people calling it a once in a lifetime run! And that was for just 29 seconds - in other words, we "only" need another nine performances just like that, and we'll have our sub-2 hour marathon! Now, how often do we expect a runner to line up and smash 30 seconds off a world record? And then of course, the ceiling effect comes into play as well, and says that once we get to the 2:02 range, it will become even more difficult.

I hear some of you saying "What about a Paula-esque performance? She took it down by 2 minutes!". And of course, this may yet happen. But just looking at Gebrselassie's pacing from this world record, you'll see that he is incredibly consistent. That suggests to me that he's right on the limit, because if he had any reserve, you'd see that through fluctuations in pace especially at the end (this is one possible interpretation, I acknowledge that). But given the fact that he took 29 seconds off the time running this kind of race, it's difficult to see how he's going to get 3 seconds/kilometer to get the time down to 2:02. As it was, he was already right on the limit.

So my feeling is that the 2:02 will eventually come, but it won't be by 2015, and a sub-2 hour time will certainly not happen with anyone from the current crop.

As for who is likely to break the world record next, my money would be on Zersenay Tadese, ahead of Bekele. A lot of people are getting hyped up over Bekele and his chances of running 2:02, but I suspect Tadese will be the dominant marathon runner from the current generation of track stars. Time will tell...

The London 2008 Marathon and some implications for the Olympics

Speaking of Dave Bedford and the London Marathon, his marathon predictions might be a little debatable, but one certainly would not want to argue the quality of the field he puts together for the London Marathon!

You can read some of the names here, but the big one is Martin Lel, defending champion and New York champ. Regular readers will know that I'm a huge fan of Lel's, I think he's the complete package, so it was with mixed feelings that I read that he's signed up for London, and that he's currently leading the lucrative World Marathon Majors series.

Why mixed feelings? Because his presence in London, combined with what must be a growing incentive to win a share of the $1 million prize purse means he is thus less likely to compete in Beijing in peak shape, if at all. No word on that yet, but I had really hoped for a race between him and Gebrselassie for the Olympic title - the best Racer in the world against the fastest marathon runner in history, would have been a great clash!

As for Gebrselassie, he is not on London's books yet, but there was talk that he might yet be signed. I seriously doubt it, because he's already running the Dubai Marathon in mid-January. If he then runs London in April, and is aiming for the Marathon in Beijing, that equals one tough year. I know I'd be advising against it, but stranger things have happened...I certainly would lengthen the odds on Gebrselassie if he runs in all three those races.

But it's a bumper field for London, Olympic and World Champions, racers, fast men, strong men, the works. And so the Marathon year will certainly get off to a great start, first with Geb in Dubai and then this field. Let's hope it is as good as the year that has just gone (we'll do a look back at the science and physiology of the year's marathons next week in our "Year in Review" series).

Paula gets hot - in South Africa

Finally, it was with interest that I read this article on Paula Radcliffe and the UK athletics team coming out to my home country, South Africa, for a training camp in January next year. The purpose of the camp is to help the athletes prepare for the Beijing heat and to help them figure out what to drink in Beijing. There are a couple of reasons why this is interesting.

One, it shows that the UK are serious about preparing for the heat, because the plan is to bring out three physiologists to help the athletes figure out their best hydration strategies. They are talking about measuring the salt and sugar content of the sweat in order to help the athletes figure out the optimal hydration strategies.

Regular readers of The Science of Sport will know that we think the best hydration strategy is to drink when you're thirsty! You can read our rationale for this in our series on fluid intake (link on the right of the page) and our series on Muscle Cramps. And it's a lot cheaper than flying athletes out for a training camp! But dodgy science practices aside, I think that this type of camp has as much a psychological benefit as it does physiological. In my experience, athletes benefit when they believe that they have done everything possible to prepare for their event, regardless of whether what they are doing actually works! And so the camp idea will certainly help, because from the article, the athletes are buying in.

One thing it will not do is help the athletes prepare for the heat - it's too far out, and they are only coming in for 10 days. So having achieved some degree of adaptation to the heat, they'll then fly back to cold and wet England and undo it all by mid-February. So the purpose is a planning, rather than a physiological one.

From a scientific point of view, there some pretty large potential potholes. For one thing, each athlete is coming out to South African for only 10 days. We know that with the body's adaptation to the heat, the sodium content of the sweat changes quite dramatically (sweat becomes more dilute). This adaptation takes about 6 days to be achieved, so let's hope the UK physiologists are at least aware of this, and don't make their "proven" recommendations based on the sweat content in the first few days! The values they get in the last few days will be very different from those in the first few! And so if they do this, the UK athletes will just about be drinking sea-water in Beijing!

Secondly, the venue they have chosen (Potchefstroom - a town close to where I grew up), is hardly comparable to Beijing. It has a typical temperature of 25 degrees, and humidity is next to nothing - think dry, and relatively mild heat. Compare Beijing, which will be like a greenhouse meets a steam bath! So I'm not convinced that they are replicating conditions as well as they might. There are two follow-up camps planned, however, and so they probably have this covered.

The other big issue, of course, is that state of training is a critical determinant of both sweat rate and sodium loss in sweat. And so therefore, one would expect the requirements in August (at the Olympics) to be very different from what they are in January, even without the additional factor of the heat! So I see great complications coming!

Again, it just re-inforces the point that because the body is so well designed, so balanced and "intelligent", it can change the amount of salt lost in the sweat depending on heat adaptation and training. So why introduce a third person (or even a second person physiologist), who simply cannot hope to understand the integration of the physiology during exercise as well as the human body can? It is a case of losing sight of the wood for the trees, and over-complicating matters.

From a practical perspective, what constitutes a successful drinking pattern? Is it the fluid intake routine that keeps the body weight the same? Is it keeping the body's salt content the same? Are you trying to keep the core temperature down? Fluid intake doesn't help this to begin with, and we know that most athletes lose weight during the course of the marathon. One thing that I will predict is that if Paula Radcliffe tries to drink so much that she doesn't lose any weight during the race, she'll never win the Olympic Gold medal - she'll be too busy worrying about stomach cramps and nausea to race properly!

Bottom line - drink to thirst. Of course, the idea to practice drinking before Beijing is a good one, and I think it would be a good exercise to allow athletes to exercise with a range of options - high sodium, low sodium, high glucose, low glucose etc., and then see which they find easiest to drink. Because if it tastes too salty to the athelte, then it probably is! The wonders of the intelligent body...

Join us again tomorrow for Part III in the series on Running Economy!

Ross

Running Economy Part II

The Biomechanics of Running Economy

Today sees Part II of our series on Running Economy. After spending the first two posts introducing the concepts and discussing the results from the Zersenay Tadese study, today we move onto some fundamental concepts of running economy - the physiology and biomechanics of running economy explained (partly, we hope!)

I say "fundamental" with some caution, because the more one digs into this particular topic, the more you realise that the science, and our knowledge of how to put running economy into practice, is still a long way off where it should be. I know that our good friend Amby Burfoot is fond of reminding us that science is actually a long way from understanding running physiology, and he's quite right. In the words of Sir Roger Banister, the first man to crack the 4-minute mile and who then went on to become a respected neurologist:

"The human body is centuries in advance of the physiologist, and can perform an integration of heart, lungs and muscles which is too complex for the scientist to analyse"

Running economy is one such 'integration". And with that in mind, let's get to it!

A fundamental paradigm - running economy: one of many explanations?

The first point that I have to make is that we should be careful not to over-emphasize the importance of running economy to performance. Yes, it is important. And yes, any coach, scientist or runner who is dedicated to training and improving performance needs to be aware of running economy and possible means to improve it. And yes, it has been relatively "forgotten" by science in recent times, hence our relatively limited understanding of it. But regular readers of The Science of Sport will also know that we're not particular fond of "magic potion", "silver bullet" training methods or science principles! So we must approach running economy for what it is - one of many explanations for performance.

So when we look at the East Africans, we note that they have a better running economy than the European runners. We also note that the best runners tend to be the most economical, that certain physiological characteristics predispose runners to be more economical, and that certain types of training improve running economy more than others (more on that in our next post, by the way). This is only partly relevant to you as you read this, because ultimately, you must not "lose sight of the wood for the trees", and become so stuck in the running economy analysis that you forget to worry about performance! And let running economy take care of itself...

Factors influencing running economy

Running economy, to repeat, is an integration of numerous systems and characteristics, biomechanical, and physiological factors. It would take a month of articles to cover all of them in detail, so we'll skim the list quite substantially, and discuss these three categories very broadly.

Biomechanical factors influencing running economy

The Zersenay Tadese article attributed his incredible running economy to the small size (and thus lighter weight) of his calves, compared to the European athletes. That is, he is carrying less weight at the extremities than they were, since his calf circumference was a good deal smaller than the Spanish runners he was compared to.

I suspect that this is only part of the answer, and possibly a very small part. As mentioned in Part I, Tadese's economy is much lower than the Kenyan runners tested before him, who probably do not have quite as much of a disadvantage as far as the calf muscle goes. So while the difference between Tadese and the Spanish might be calf-size related, there is more to it than just this.

According to an excellent review article from 2004 (by Saunders, published in Sports Medicine, 2004), the following biomechnical factors are important for running economy:

• Height: Slightly smaller than average is better for men, while slightly taller is better for women - I must confess that I don't have an explanation for the difference!
• Somatotype: Ectomorphic physique demonstrates best running economy. An ectomorph is generally long-limbed, thin, has shoulders that are about the same width as the hips! Think Paul Tergat, or just about any Kenyan long distance runner!
• Body fat: Low percentage, because body fat represents additional weight that must be carried, increasing the oxygen cost of running
• Leg morphology: Most of the weight distributed closer to the hips. In other words, if you have mass, carry it in the quads and not the calves! This agrees with the suggested reasons for Tadese's economy
• Pelvis: Narrow
• Feet: Smaller than average
• Shoes: Lightweight but well cushioned. There is evidence that cushioning improves running economy, possibly because it reduces the work required by the muscle to absorb and cushion the landing (that's the theory, anyway)
• Stride length: Freely chosen. This is interesting, because there is evidence from research that if you chop your stride to try to increase the cadence, your running economy worsens. We touched on this in our series on Pose running recently, and a lot of people find that they chop their stride when trying to use the method. According to the economy research, this would be undesirable. Having said that, if you are overstriding, then it's just as bad, if not worse, because a great deal of energy is lost in braking. This factor, perhaps more than any other, emphasizes that "Practice makes Perfect" and that running is a skill which must be practiced and learned. It happens naturally, yes, but it must be learned.
• Kinematics: A few things here - first of all, low vertical oscillation of the centre of mass. What does this mean? Well, it means don't waste time going up and down if you don't need to. The less you waste on vertical braking forces, the better. It was always rumoured that the most economical runners were effectively "rolling" their legs along beneath their hips - this is in fact a premise of Pose Running, as we discussed once before. There is nothing new to this at all (despite the fact that it was packaged as 'revolutionary', because we've known for a long time that a relatively flat trajectory is more economical.
• Secondly, minimal possible movement of the arms. That's not to say zero movement, because the arms play an important role in providing some rotational stability, but the movement must not be excessive. On this note, you see some absolutely bizarre arms carries among the elite runners, which you'd have thought would be corrected, but that only re-inforces that this is not an exact science.
• Third, a more acute knee angle during the swing phase. In other words, when your trail leg is coming through (eg. your right foot is planted on the ground and your left leg is catching up), then it's better to have that knee fully bent than straight. The reason for this is physics, relating to rotational torque and the force that is required of the muscles to bring the leg through. But the practical point is that the hamstrings come into play to reduce running economy, because they contribute to the flexing of the knee. One practical issue here is that when running slowly, it's almost impossible to bend the knee more than a few degrees - you'd be working so hard to bend your knee, the effect would be increasing your cost, not reducing it! So this is largely influenced by running speed.
  

Then there are a couple of other factors, which we'll touch on as we develop our discussions further in the next few posts.

But what is important to take out of the above list is that if you are a tall, skinny man, weighing next to nothing, with hips as wide as your shoulders, short arms, no body fat, and you wear a well-cushioned pair of size 6 shoes, you might have a good running economy!

The most important thing that jumps out from the above list is that there are some factors that one is born with (narrow pelvis, foot size, height, distribution of weight on the legs) and others that are improved with training and preparation, such as the kinematics like vertical oscillation and arm carry. Point is, great runners are born, and then trained. But everyone can run, and so as you read this, there is probably a great deal that you can do to improve your running economy, which would then translate into improved performance. But we'll discuss that in a separate post, later in the week.

Join us then!
Ross

Running Economy Part I

The Zersenay Tadese study - the most economical runner ever?

Yesterday we introduced a new series, Running Economy, inspired by this study, which was published just last week in the British Journal of Sports Medicine. It makes a great start to a series that we'll build on next week, looking at the importance of running economy to performance.

We must of course make the disclaimer that just as VO₂max does not by itself guarantee performance, so too running economy is one of many possible variables, both physiological and psychological, that come into play when one tries to understand just what is goes into determining performance. But it certainly seems to be an important one...we spoke yesterday of the growing awareness of running economy as a crucial determinant of performance, and of how little is known about it.

So it is perhaps fitting to begin our series with the very latest work, and then we'll deconstruct the theories as we progress.

The Zersenay Tadese Study

The title of the research article that was published last week was "The key to top-level endurance running performance: A unique example". The researchers, based in Madrid, Spain, had access to Tadese, the World Cross Country champion who put an end to the reign of Kenenisa Bekele earlier this year. He then followed this up with a win in the World Half-Marathon championships, where he beat world record holder Sammy Wanjiru, running 58:59, in a race where some time may have been lost due to tactical manoevuring in the middle part of the race!

Zersenay Tadese is a class act. Regular readers will know that I (Ross) am a particular fan of his, and recently picked him to be the next world record holder in the marathon, when he eventually makes the move up from the track. I think he might even have a more successful marathon career than Bekele. And if he gets the preparation right, Beijing 2008 might also see him challenge Bekele on the track. So it was with some personal interest that we discovered this article, courtesy George.

Looking at the study, it is always remarkable to have access to such a uniquely talented athlete, clearly at the peak of his 'game'. It's always been one of the big barriers to understanding the 'eternal mystery' of the dominance of the Kenyans that they've never really been studied in their prime. Most of the published work done on the East Africans comes from the labs of Bengt Saltin, and while those runners were certainly talented, they were by no means the best Kenyans in their best condition. And of course, there's a potentially crucial difference between the Kenyan who can run 27:30 for 10k compared to the one who runs under 27 minutes! So the fact that Tadese was tested during the month leading up to the World Cross Country Championships, and that he allowed the results to be published is a great coup for the researchers.

So let's take a look at the results...

Blood hematocrit

The first finding of interest is the hematocrit, measured one week before the Championships. It was "only" 43.7%. I say "only" because in another endurance sport, cycling, I suspect that many riders would not even get out of bed on pull on their jerseys if it was this low! In fact, the value of 44% is pretty much in the normal range, considering that he was doing a moderate to high volume of training at the time of testing (about 150km/week).

The authors suggested that this measurement, together with other findings we won't go into here, indicates "no manipulations to artificially increase blood oxygen transport capacity", and "no artificial stimulation of erythropoiesis". I'm sure sceptics are out there (they'd hardly report it if his hematocrit was 58%, would they!), but we'll go along with that one. Let's get onto running economy.

Running economy

We introduced the concept of running economy yesterday, but it bears repeating. Running economy is a measure of how much (or little, as the case may be) oxygen the runner uses for a given, sub-maximal speed. In theory, two runners can have the same maximal capacity for oxygen use (called VO2max), and then the one who is more economical at the sub-maximal speeds is likely to be the better runner.

So there are two measurements we need to look at here. The first is the MAXIMUM - the VO2max. The second is the oxygen use at sub-max, which tells us how economical Tadese is.

VO2max

Zersenay Tadese's VO2max was reported as 83 ml/kg/min. This is a very high measurement, but that's expected of a world class long distance runner. When compared to other world class athletes, Tadese's value 'disappears' into the crowd. In otherwords, if we lined up a group of athlete's VO2max values and asked you to pick the the two-time World Champion based on VO2max alone, there's a good chance you'd be wrong! Just as you would have been completely wrong when you had to guess that Derek Clayton could run a 2:08 marathon with his VO2max of "only" 69 ml/kg/min.

Of course, when it comes to VO2max, there's a lot of hype around the measurements. It has become something of an urban legend, much like the size of the fish you caught on your last fishing expedition which gets larger every time you re-tell the story! So depending on who you believe, Greg Lemond had a VO2 max of 92.5ml/kg/min, the Cross-Country skier Bjorn Daehlie was at 96 ml/kg/min in the off-season, and the physiologist who tested him predicted that he'd be above 100 ml/kg/min when he was "fit"! We're pretty sure you can relate your own stories of this super-human measurement!

Incidentally, while we're talking super-human, the Siberian huskies who take part in Alaska's Iditarod Sled Dog Race have been reported as having VO2 max values of 240 ml/kg/min! Eat your heart out, Bjorn!

Running Economy

So now we move onto running economy.

First things first – we have to understand what they are measuring. They have measured running economy as the total volume of oxygen needed to run 1 kilometer. This is really important, because there is evidence, shown in the Figure below, that this total volume does not vary too much with running speed. In otherwords, regardless of how fast you run, you use more or less the same volume of oxygen to run 1 kilometer! Of course, there will be individuals who don’t quite follow this trend, and so some runners will become more or less efficient as they run faster, but in general, it stays similar.

Figure showing schematic values of oxygen cost to run 1 km in three
different population groups. Note that the data are schematic only,
and represent pooled values for the three groups. Note also the general
absence of a change in economy as running speed increases.
Redrawn from Foster and Lucia (2006)

Now this might be confusing at first (certainly took some figuring out from our side – it has major implications for our understanding of fatigue, actually), because you’ve no doubt heard that the faster you run, the more oxygen you use. And this is still true – the trick is to understand the units that economy is being reported in. This is illustrated in the following example:

Take a runner who runs along at 4min/km, and uses about 200 ml/kg of O₂ to run 1 km. If we look at his O₂ use per minute, then we work out that he is using 50 ml/kg/min (because it takes him 4 minutes to run that kilometer and use those 200ml/kg of oxygen). If our runner increases his speed to 3min/km, if we assume that his total oxygen to run 1 km remains 200ml/kg (again, we acknowledge that some people will differ, but generally, as the figure above shows, this is the case). But now, he’s only taking 3 minutes to run the kilometer (and hence use those 200ml/kg of O₂). Therefore, his actual use of oxygen PER MINUTE is now 67 ml/kg/min!

So in fact, the use of oxygen PER MINUTE goes up with running speed, but the use per kilometer remains relatively constant. This is important (and has MASSIVE theoretical implications, but that is for another day). The other thing about this figure is that it creates a number of questions – why are the East Africans lower than the Caucasians, for example? But that’s all for the later posts in this series. Let’s get back to Tadese.

Tadese has one of the lowest total volumes of oxygen to run 1 kilometer ever reported. In the article, the authors report the following “normal” values for running economy, measured as ml/kg/km (that is, volume used to run 1 km)

• Frank Shorter – 192 ml/kg/kilometer (running at 3:06/km)
• Elite Kenyans (including Olympic medallists) – 192 ml/kg/kilometer (running 3:00/km)
• Elite Caucasians (Spanish runners) – 211 ml/kg/kilometer (running 3:09/km)

• Zersenay Tadese – 150 ml/kg/kilometer (running at 3:09//km and at at 2:51/km)

The size of this difference is astounding. We do have reports of runners who have been tested in this range, but we just need to get permission to publish the results (we’re working on that!). But let’s put this into context:

• Tadese is running along at 3:09/km, which is a 2:13 marathon pace.
• He is using 150 ml/kg of Oxygen to cover each kilometer.
  
• If we now convert this to a volume per MINUTE, we work out that he is using 47.6 mlO₂/kg/min. This is absolutely astonishing for how low it is!
  

We cannot emphasize just how significant this is – quite what it means, and the implication thereof is something we will tackle in another post, possibly even another series (we don’t want to go off on a tangent here!).

What is wrong with this picture?

But just think about something for a moment – Tadese has a VO2max of 83 ml/kg/min, and he runs at 3:09/km using only 48 ml/kg/min. Therefore, he is using only 57% of his “maximum” at this speed.

There is good evidence that athletes are able to run for 2 hours at about 80% of their VO2max. Now, if Tadese did this, he would be able run at 66 ml/kg/min. Given his Running Economy of 150 ml/kg/km (which is 'relatively' independent of speed - see Figure, and was similar for Tadese in the two speeds he was tested at), this would mean he could cover each kilometer in 2 minutes 18 seconds! Even if his running economy worsened quite a lot and he used up 180 ml/kg/km (a 20% increase), he'd still have it in him to run 2:45/km!

Quite clearly, this is not possible. So either Tadese becomes MUCH LESS efficient as running speed increases (which is somewhat out of the ordinary, as the figure demonstrates - slight changes, sure, but not so large), or something else is going on - there's something wrong with this picture. We need to address this, but as I've said, that's another can of worms!

The inevitable disclaimer...

I have no doubt that people will attack some of the assumptions we’ve made, and so we might as well declare right now – “We know, we've made some assumptions here, the key one being that economy (as measured per kilometer) doesn't change with speed, but we use this to illustrate a potentially profound point for our understanding of what limits exercise performance”. Think about it – if you’re running along at 80% of VO2max, then you have the capacity to use more oxygen. Yet you don’t. So how then, can oxygen be limiting, as you’ve probably read many times? Interesting one that…but that’s for another day…

Explaining Tadese’s extra-ordinary running economy

So now we move onto a mechanism – how do we explain this unbelievably low use of oxygen? Well, the authors put a few things out there:

• Very efficient utilization of oxygen by working muscles
• Training
• Muscle fibre distribution
• Genetic Factors
• And then the big one, anthropometric characteristics. That is, they measured the mass and size of the calf and found that Tadese had a significantly smaller calf muscle than the Caucasian runners, who had Running economies of 211 ml/kg/km.

With that, which I’m sure many of you are thinking is a very generic set of reasons and mechanisms, we’ll sign off today! But that’s on purpose, because in our next post on the series, we’ll look at what factors contribute to running economy in more detail – what is training, muscle fibre distribution, genetics? And then we can all compare ourselves to Tadese and work out why we’ll never be that economical!

Bye for now!

Ross

Running Economy Introduction

Zersenay Tadese - the most economical runner in history?

Well, a provocative headline for sure, but that's pretty much what a SCIENTIFIC study has suggested after measuring the oxygen consumption and running economy of the World Cross Country and Half Marathon champion recently! The study, published just the other day in the British Journal of Sports Medicine, and performed by Carl Foster and Alejandro Lucia, found that Tadese has one of the best (if not THE best) running economies ever measured. That is, he uses LESS oxygen at the measured running speed than any runner reported before him.

I would not question the study for a second (well, not too critically, anyway), as Foster and Lucia are both excellent scientists, with great records in the field. Foster is famous for his modeling of pacing strategy and performance, while Lucia has been one of the leading researchers in cycling performance, doping and the physiology of performance. So some credible names, and a fascinating paper, for sure!

We are always on the lookout for interesting news stories here at The Science of Sport, and we do our best to take sports news and exaplain the science behind it. But this particular story is both newsworthy and science-worthy at the same time, and we say thanks to George (a self-described devoted reader of the blog) for bringing it to our attention!

Introduction of a new series - running economy

What we would actually like to do before we analyse this paper (and Tadese's new claim to fame) in tomorrow's post, is to use this really great story to introduce a new series and discussion around this concept of running economy. I seem to recall that about three months ago, there was a whole spate of articles on running economy - for some reason, it suddenly shot to prominence and a number of widely read newspapers started writing about it as though it was the very latest thing, even though we've known about its importance for about 30 years. And even back then, we considered the prospects of some posts about running economy, but they got kind of swept away by the heat of Chicago and the racing in New York. Well, no time like the present to go back there!

Running economy 101: What is the big deal?

To begin with, running economy in humans is probably analogous to cruising-efficiency in a car (not entirely, but we'll get there!). If you think of a human, we can measure the maximum volume of oxygen that can be used, and this is called the VO2 max or VO2 peak. The problem is, for most running events (certainly above about 5000m), runners don't use this "maximum" amount - they are sub-maximal. And so therefore, a more important measure becomes the volume of oxygen that is used up when the runner is going at a sub-maximal speed.

So to return to our fuel analogy, it's saying that the car is cruising along at a speed lower than maximal, and we're interested in how much fuel it uses per kilometer.

Now, there is plenty of reason to think that running economy is very important. There used to be a perception, which still exists in many circles, that the be-all and end-all of running performance was the VO2 max value. In other words, you'll still find people who think that the runner who has the highest VO2 max is the guaranteed winner. Many runners who have been tested wear their VO2 max like a badge of honour if it's high, whereas they hide it away if they think it's low, such is the importance that has been placed on this measurement.

And of course, it is still crucial that a world class runner have a higher than average maximum ability to use oxygen. So you'd be very hard pressed to find any world-class runner who has a VO2 max lower than about 70 mL/kg/min (this is the unit for VO2 max, by the way - it's a volume in mL, expressed relative to body weight over time). Your typical moderately fit male, weighing about 80kg, would have a VO2 max of about 50 to 60 mL/kg/min, and a fairly well trained athlete might hit the mid 60's, with the better ones being higher than this, into the 70's and 80's. So there is a "GENERAL" trend for the fitter, more highly trained athlete to have a higher VO2 max (although we would argue that is a consequence and not a cause of performance).

But then there's a catch - Maximum is not the deciding factor

The reality however, is that you don't always get this nice, uniform increase in performance with an increase in VO2 max - often times, a guy with a VO2 max of "only" 75 ml/min/kg will beat a runner whose VO2 max is "superior" at 85 ml/min/kg. And so clearly, there is more at play than simply the size of your lungs, your heart and the muscles maximum ability to use oxygen.

Intuitively, you recognized that this makes sense - as we pointed out above, because 10000m races are run about 90% of VO2 max, and marathons are run at 80 to 90% of VO2 max, there is room for difference because it's the runner's ability to use the oxygen most efficiently that contributes a substantial amount to performance.

So that's where running economy enters the equation. Whenever you read a book on this subject (be it Lore of Running, or any other text), you always see the concept of running economy introduced in this way - it's the excuse for the "little guy" (in terms of maximal oxygen use, anyway), beating the big guy!

Considering how important running economy seems to be, it's apparently been ignored in the literature. Last year, in October, a seriously high-powered gathering of exercise physiologists and scientists gathered in Chicago for a conference on Marathon Medicine and Physiology.

And at that conference, Carl Foster, one of the authors of the Tadese paper, discussed the role of running economy in performance. He suggested that the science has "ignored running economy" to date, despite knowing about it for 30 years, and as a result, relatively little is known about the topic.

It therefore seems like a nice, juicy and interesting topic to tackle in a series, and so what we'll do over the next couple of weeks is take a look at running economy. We'll begin with an analysis of the study on Zersenay Tadese, which began this post, then we move onto the importance of running economy, the factors determining running economy, and methods that you can use to improve your running economy, and hopefully performance.

So join us over the next few weeks as we get into what could be a very interesting discussion!

Ross

Fukuoka Marathon 2007

Sammy Wanjiru's debut party goes as planned

This past weekend saw the 61st running of the Fukuoka Marathon, which until a few weeks ago promised an epic dual between the seasoned veteran Paul Tergat and the up-and-coming Sammy Wanjiru. Unfortunately Tergat pulled out, leaving no one who could, on paper at least, touch Wanjiru's potential.

Wanjiru has been devouring competitors in the half-marathon since 2005, when he set his first world record over that distance (59:16 at Rotterdam). He lost that record to Gebrselassie in January 2006, only to break it again in February of this year in Ras Al Khaimah (UAE) with a new time of 58:53. However that record was not ratified as no EPO testing was carried out at the race. Undeterred, he promptly lowered that time to 58:33 in March at the Fortis City-Pier-City Half Marathon in Den Haag. He later committed to Fukuoka as his marathon debut and had all eyes upon him this weekend---could be break Evans Rutto's debut record of 2:05:50?

The race: Wanjiru never in trouble

It was a typical race of attrition as the pace setters did their job and one by one runners dropped off the pack. By 20 km only 15 runners remained in contention, and five km's later only 10 remained. At 30 km the rabbits' job was complete, leaving just two other runners to challenge the novice Wanjiru. At that point he and Japanese national Atsushi Sato tightened the screws and ripped off a few fast splits:

31 km: 2:58
32 km: 3:01
33 km: 2:57
34 km: 2:58
35 km: 2:52

It was Wanjiru himself who attacked during the 35th km, breaking Sato and leaving only Deriba Merga of Ethiopia. Wanjiru then toocontrol as he surged again to break Merga:

36 km: 2:56
37 km: 3:04
38 km: 2:57
39 km: 3:11

Merga was dropped, but hung on to smash his own PB by over six minutes and also borke the prvious course record and finished only 11 seconds behind the debutante Wanjiru. A stellar run by Wanjiru, to be certain, but very brave running by the young Ethiopian who showed class and form by clinging to Wanjiru for so long and losing by a relatively small margin.

The official splits for Wanjiru as he broke the course record by 12 seconds :

5 km	15:04
10 km	30:02
15 km	45:06
20 km	1:00:11
21.1 km	1:03:30
25 km	1:15:04
30 km	1:30:05
35 km	1:44:49
40 km	2:00:03
42.2 km	2:06:39

What is next for the young star?

So everything appears to be going exactly as planned for Wanjiru. He seems to be connecting the dots one by one from a very young age and turning in big performances along the way. Wanjiru claims to have Olympic Marathon aspirations, and so far has met his goal of debuting with a 2:06 marathon. His next goal is to run 2:05 in a spring marathon, perhaps London, in hopes that a feat of that magnitude will secure him a spot in Kenya's Olympic Marathon team. Another performance like this in London will signal his arrival on the Big City marathon scene. This past weekend, although matched against the best Japan has to offer, he did not run against such a stellar field. London's ability to secure both the fastest runners and best racers is legendary, and Wanjiru must prove he can beat the experience of guys like Felix Limo, Evans Rutto, Jaouad Gharib, Daniel Njenga, Robert Cheruiyot, Paul Tergat and Gebrselassie, among others. For now, though he owns the course record in Fukuoka and remains on a larger path to more success.

Muscle Cramps: Part V

What all this means for you

We have now run the entire gamut in this series on cramps, and it has been quite a ride. This series generated the more reader interest than any of our other posts or series, and let us say again how grateful we are for your participation in the debates and discussion. As academics, we hold fast to the old adage that there is no such thing as a stupid question, and all of us, expert or novice, must ask questions to learn and advance our own knowledge. And this was a complicated series, so we really thought it might be a good time to try to summarize what, exactly, does all of this mean for you the athlete?

Who experiences cramps?

There does seem to be a predisposition cramps. To date no one has even tried to identify the gene(s) that might predispose one to cramping, but even a general survey of the active population will reveal that some people cramp both at night and during exercise, while others never cramp. So you might indeed be a "cramper" before you even toe the line!

What causes them?

We have presented two models for the cause of cramps. The first model tries to explain them based on electrolyte disturbances and dehydration. The second model is based on neural activity and muscle excitation and relaxation. So which one is correct?

The short answer is that we do not know exactly what causes cramps, and it will likely be many years (perhaps even decades) before someone presents a more definitive model that better explains their cause. As we mentioned in a recent post, science is like watching one chess square and trying to create hypotheses based on observations of that one square. We have presented the available scientific evidence, and have drawn our conclusions based on that evidence. Does that make our conclusions correct? To be certain, "No not necessarily!" It merely represents our interpretation of the data.

The bottom line here is that it is a complicated mechanism, like so many others in the body. Also, just as our many different systems are affected by a vast array of factors and circumstances, so is the cause of cramps, and until we have a reliable laboratory protocol that can reproduce cramps in a predictable manner, we cannot really test the models further.

Ok, so I am a cramper. . .now what do I do?

There are a couple of key points here:

1. Regular stretching will help reduce the incidence of your cramps. This is because, as we explained in Part III, stretching will reduce the alpha motor neurone activity, and thus reduce muscle contraction---which is all a cramp is anyway, an uncontrolled contraction. Therefore stretching often is recommended especially if you know you are a cramper.
2. "I swallow an electrolyte pill and my cramping stops." This is a comment we hear often, and although we cannot explain this physiologically, the more important message is that you have found something that works for you. We cannot stress how important this is! All the science in the world can point to something, but if what you are doing works for you, then you are better to stick with that technique. We invest so much time and energy (i.e. blood, sweat and tears!) into our training, and if you know that taking some supplement---providing it is legal, of course---will prevent a cramp during your marathon, then by all means you must take it.

But wait. . .I am not a cramper, how can I reduce my chances?

Fatigue appears to be a common factor in cramps, and so preventing fatigue or delaying its onset is crucial. However, we can hear you all the way in Chicago and Cape Town saying, "Great! if only it were that easy. . why didn't you just say so?"

First of all, "Out running" your training could be a likely contributor to cramps. By this we mean that you know good and well that you have done the training for a 3:30 marathon, but in spite of that you decide you are going to go out at 2:55 pace. You feel great for about two hours, and then all hell breaks loose, the wheels fall off, and you are left in a crumpled heap with 5-10 km to go. Therefore we would suggest trying to race closer to your abilities in an effort to reduce the amount of fatigue you acquire during the event.

Second, progressive training is something else that we can all practice that will likely help reduce the chances that we cramp. Don't go from "zero to hero" and make large increases in your training from week to week. As many of you might already know, rest is just as important as all the intensity and distance work you do, because it is during rest periods that your body actually makes the adaptations. Therefore small and incremental increases in training with appropriate rest will provide your body with the maximum time to make the necessary adaptations, and it is those adaptations that will delay the onset of fatigue.

Physiology is a complicated topic, and the available evidence on cramps is sparse. To really advance our knowledge we need solid lab studies that help us identify exactly what is going on and why the cramps occur. In fact, just creating a reliable and reproducible lab protocol would be a major step in identifying what causes the cramps in the first place. However cramps tend to be unpredictable in most people, and even in the known "crampers" it is difficult to bring them in the lab and make them cramp 100% of the time. So the beat of science marches on, and we can only hope that even as you read this, some PhD student out there is hard at work dreaming up a thesis that investigates this issue and tries to advance our knowledge!