Could the low testosterone problem be a mirage?

Low testosterone (a.k.a. “low T”) is caused by worn out glands no longer able to secrete enough T, right? At least this seems to be the most prevalent theory today, a theory that reminds me a lot of the “tired pancreas” theory () of diabetes. I should note that this low T problem, as it is currently presented, is one that affects almost exclusively men, particularly middle-aged men, not women. This is so even though T plays an important role in women’s health.

There are many studies that show associations between T levels and all kinds of diseases in men. But here is a problem with hormones: often several hormones vary together and in a highly correlated fashion. If you rely on statistics to reach conclusions, you must use techniques that allow you to rule out confounders; otherwise you may easily reach wrong conclusions. Examples are multivariate techniques that are sensitive to Simpson’s paradox and nonlinear algorithms; both of which are employed, by the way, by modern software tools such as WarpPLS (). Unfortunately, these are rarely, if ever, used in health-related studies.

Many low T cases may actually be caused by something other than tired T-secretion glands, perhaps a hormone (or set of hormones) that suppress T production; a T “antagonist”. What would be a good candidate? The figure below shows two graphs. It is from a study by Starks and colleagues, published in the Journal of the International Society of Sports Nutrition in 2008 (). The study itself is not directly related to the main point that this post tries to make, but the figure is.



Look at the two graphs carefully. The one on the left is of blood cortisol levels. The one on the right is of blood testosterone levels. Ignore the variation within each graph. Just compare the two graphs and you will see one interesting thing – cortisol and testosterone levels are inversely related. This is a general pattern in connection with stress-induced cortisol elevations, repeating itself over and over again, whether the source of stress is mental (e.g., negative thoughts) or physical (e.g., intense exercise).

And the relationship between cortisol and testosterone is strong. Roughly speaking, an increase in cortisol levels, from about 20 to 40 μg/dl, appears to bring testosterone levels down from about 8 to 5 ηg/ml. A level of 8 ηg/ml (the same as 800 ηg/dl) is what is normally found in young men living in urban environments. A level of 5 ηg/ml is what is normally found in older men living in urban environments.

So, testosterone levels are practically brought down to almost half of what they were before by that variation in cortisol.

Chronic stress can easily bring your cortisol levels up to 40 μg/dl and keep them there. More serious pathological conditions, such as Cushing’s disease, can lead to sustained cortisol levels that are twice as high. There are many other things that can lead to chronically elevated cortisol levels. For instance, sustained calorie restriction raises cortisol levels, with a corresponding reduction in testosterone levels. As the authors of a study () of markers of semistarvation in healthy lean men note, grimly:

“…testosterone (T) approached castrate levels …”

The study highlights a few important phenomena that occur under stress conditions: (a) cortisol levels go up, and testosterone levels go down, in a highly correlated fashion (as mentioned earlier); and (b) it is very difficult to suppress cortisol levels without addressing the source of the stress. Even with testosterone administration, cortisol levels tend to be elevated.

Isn't possible that cortisol levels go up because testosterone levels go down - reverse causality? Possible, but unlikely. Evidence that testosterone administration may reduce cortisol levels, when it is found, tends to be rather weak or inconclusive. A good example is a study by Rubinow and colleagues (). Not only were their findings based on bivariate (or unadjusted) correlations, but also on a chance probability threshold that is twice the level usually employed in statistical analyses; the level usually employed is 5 percent.

Let us now briefly shift our attention to dieting. Dieting is the main source of calorie restriction in modern urban societies; an unnatural one, I should say, because it involves going hungry in the presence of food. Different people have different responses to dieting. Some responses are more extreme, others more mild. One main factor is how much body fat you want to lose (weight loss, as a main target, is a mistake); another is how low you expect body fat to get. Many men dream about six-pack abs, which usually require single-digit body fat percentages.

The type of transformation involving going from obese to lean is not “cost-free”, as your body doesn’t know that you are dieting. The body “sees” starvation, and responds accordingly.

Your body is a little bit like a computer. It does exactly what you “tell” it to do, but often not what you want it to do. In other words, it responds in relatively predictable ways to various diet and lifestyle changes, but not in the way that most of us want. This is what I call compensatory adaptation at work (). Our body often doesn’t respond in the way we expect either, because we don’t actually know how it adapts; this is especially true for long-term adaptations.

What initially feels like a burst of energy soon turns into something a bit more unpleasant. At first the unpleasantness takes the form of psychological phenomena, which were probably the “cheapest” for our bodies to employ in our evolutionary past. Feeling irritated is not as “expensive” a response as feeling physically weak, seriously distracted, nauseated etc. if you live in an environment where you don’t have the option of going to the grocery store to find fuel, and where there are many beings around that can easily kill you.

Soon the responses take the form of more nasty body sensations. Nearly all of those who go from obese to lean will experience some form of nasty response over time. The responses may be amplified by nutrient deficiencies. Obesity would have probably only been rarely, if ever, experienced by our Paleolithic ancestors. They would have never gotten obese in the first place. Going from obese to lean is as much a Neolithic novelty as becoming obese in the first place, although much less common.

And it seems that those who have a tendency toward mental disorders (e.g., generalized anxiety, manic-depression), even if at a subclinical level under non-dieting conditions, are the ones that suffer the most when calorie restriction is sustained over long periods of time. Most reports of serious starvation experiments (e.g., Roy Walford’s Biosphere 2 experiment) suggest the surfacing of mental disorders and even some cases of psychosis.

Emily Deans has a nice post () on starvation and mental health.

But you may ask: What if my low T problem is caused by aging; you just said that older males tend to have lower T? To which I would reply: Isn’t possible that the lower T levels normally associated with aging are in many cases a byproduct of higher stress hormone levels? Take a look at the figure below, from a study of age-related cortisol secretion by Zhao and colleagues ().



As you can see in the figure, cortisol levels tend to go up with age. And, interestingly, the range of variation seems very close to that in the earlier figure in this post, although I may be making a mistake in the conversion from nmol/l to ηg/ml. As cortisol levels go up, T levels should go down in response. There are outliers. Note the male outlier at the middle-bottom part, in his early seventies. He is represented by a filled circle, which refers to a disease-free male.

Dr. Arthur De Vany claims to have high T levels in his 70s. It is possible that he is like that outlier. If you check out De Vany’s writings, you’ll see his emphasis on leading a peaceful, stress-free, life (). If money, status, material things, health issues etc. are very important for you when you are young (most of us, a trend that seems to be increasing), chances are they are going to be a major source of stress as you age.

Think about individual property accumulation, as it is practiced in modern urban environments, and how unnatural and potentially stressful it is. Many people subconsciously view their property (e.g., a nice car, a bunch of shares in a publicly-traded company) as their extended phenotype. If that property is damaged or loses value, the subconscious mental state evoked is somewhat like that in response to a piece of their body being removed. This is potentially very stressful; a stress source that doesn’t go away easily. What we have here is very different from the types of stress that our Paleolithic ancestors faced.

So, what will happen if you take testosterone supplementation to solve your low T problem? If your problem is due to high levels of cortisol and other stress hormones (including some yet to be discovered), induced by stress, and your low T treatment is long-term, your body will adapt in a compensatory way. It will “sense” that T is now high, together with high levels of stress.

Whatever form long-term compensatory adaptation may take in this scenario, somehow the combination of high T and high stress doesn’t conjure up a very nice image. What comes to mind is a borderline insane person, possibly with good body composition, and with a lot of self-confidence – someone like the protagonist of the film American Psycho.

Again, will the high T levels, obtained through supplementation, suppress cortisol? It doesn’t seem to work that way, at least not in the long term. In fact, stress hormones seem to affect other hormones a lot more than other hormones affect them. The reason is probably that stress responses were very important in our evolutionary past, which would make any mechanism that could override them nonadaptive.

Today, stress hormones, while necessary for a number of metabolic processes (e.g., in intense exercise), often work against us. For example, serious conflict in our modern world is often solved via extensive writing (through legal avenues). Violence is regulated and/or institutionalized – e.g., military, law enforcement, some combat sports. Without these, society would break down, and many of us would join the afterlife sooner and more violently than we would like (see Pinker’s take on this topic: ).

Sir, the solution to your low T problem may actually be found elsewhere, namely in stress reduction. But careful, you run the risk of becoming a nice guy.

The low-carb, high fat diet debate and deviant thinking

The low-carb high fat diet debate: Three videos, and thoughts on polarized views and 'deviant' thinking

One of the hot topics in exercise science and diet is the low-carb, high-fat diet concept, now backed vocally by Prof Tim Noakes in South Africa.  In December, he and Prof Jacques Roussouw debated the dietary guidelines with respect to cholesterol and its impact on heart disease, and a video of that debate can be found below.  The low-carb diet echoes other topical issues in exercise science, perhaps most notably barefoot running, in that it polarizes opinions between two opposing camps.  It then strays into 'rules' and over-simplifications, which are arguably incorrect.  Here's how to 'pole-spot' and embrace complexity, along with the low-carb debate

- Ross Tucker

In the course of a debate on doping and cycling a few years ago, a certain well-known exercise physiologist who had tested and defended Lance Armstrong publicly dismissed Jonathan and I as "newly-minted scientists".  True, of course, since we had both obtained our qualifications within four years of him writing those words.

He intended it as disrespectful at the time, suggesting ours was an opinion not worth listening to because we did not have 300 years of experience (and about as many conflicts of interests, I'd add) behind us.  I always viewed "newness" as a distinct advantage, because it brings with it some aspect of novelty, a new way of approaching an old problem.  That's often lacking in science and in many areas of life (coaches, managers, I'm looking at you!), and as I've evolved from newly minted to (recently?) minted, I've come to recognize that progress usually comes from forcing a novel view.  

Deviant thinking and innovation

I recently spoke to a group of financial consultants about the lessons I have learned about high performance teams from my involvement with sports teams and athletes, and one thing that I tried to re-inforce, in business and in sport, is that progress is the result of so-called deviant thinking.  By "deviant", I mean that person who pushes back against convention, who asks the apparently ridiculous questions and forces others to rethink their positions of comfort.  Deviants make us anxious, but they also drive innovation.

If we are allowed to drift along with the current, we never challenge paradigms.  Jonathan and I were both fortunate that our post-graduate training was overseen by Prof Tim Noakes, who is not newly minted but has retained the capacity to challenge current beliefs.  He is a scientific "deviant", in the most complimentary sense of the word.  In so doing, he has driven a change in perceptions around fluid intake and dehydration during exercise, and also has contributed to our understanding of fatigue and the role the brain plays in performance regulation.  These topics were, respectively, the subject of Jonathan and my PhDs, and so we have inherited this desire to push back against convention, hence the existence of, and many of the approaches and articles on, this website.

The low-carb high-fat diet debate

The latest area of Noakes' interest is diet.  Specifically, he is a vocal proponent against carbohydrates and processed food, arguing for a high fat, low carb diet.  In South Africa, it is impossible to give a presentation on exercise and health without some member of the public asking about Noakes' dietary views and their implications for exercise, weight loss and health.

However, it is not a topic whose specific content and details I am comfortable dealing with.  I am not an endocrinologist, nor a cardiologist, nor a dietician.  I understand the basics, but in the same way that my driver's license does not entitle me to tell Michael Schumacher, Sebastian Vettel or Jimmie Johnson how to drive, I would not presume to educate or correct the experts on diet and cardiology - I might ask them a few pointed questions, of course, and challenge their thinking, but there's a line that I wouldn't cross in terms of dictating to them.  I have not dealt with people struggling to lose weight, and have not encountered the very real, practical challenges they face.  I do not have a lifetime of expertise evaluating research studies on heart disease, though I can appreciate how many 'holes' exist in current thinking.  Nor have I devoted any length of time to evaluating the respective sides of this particular debate.

And so I won't delve into specifics, at least not now.  However, in order to make the debate as widely accessible as possible, which is important, I want to share with you three videos.  They are taken from the University of Cape Town's Centenary Debate, held last year in December, where Prof Tim Noakes and Prof Jacques Roussouw debated various aspects of the high fat diet.  The focus is very much on cholesterol and its links with heart disease.  The videos are long, but worth watching when you have the time.  I'd love your feedback, your thoughts on who "won" the debate and what it means for our understanding.  Those videos are at the bottom of this post.  

Thoughts on scientific concepts and complexity

But first, my view on this whole debate, without delving into the specifics.  My biggest "objection" as it were, is not to the content of the debate, but rather the manner and justification for each side's respective positions.  Below is part of a presentation I gave to the public last year, and in it, I mention two examples of how scientific progress and application to the public can be undermined by the natural, human desire to simplify the message and adopt a polarized view of what are actually very complex concepts.  (Click here if you are reading this in an email)

The first is the 10,000 hour concept for expert performance - a great theory, wonderful to motivate parents and young athletes about the value of training, but a pretty useless theory in practice - in sport, it hardly ever applies.  The second is barefoot running, which has been taken and transformed into a cure for everything without any evidence.  

Polarized science, rules and a wildly swinging pendulum

The result of these kinds of debates is a polarized science, one where the pendulum swings wildly from one extreme to the other.  We go from "Practice is the only thing" to "Genes are the only thing" and back.  Or from "Barefoot running will prevent all injuries" to "Barefoot running is a fast-track plan for physical therapists".  Neither is true as a "rule", though within any population, there will be those who succeed at the extremes, and those who fail.  That of course introduces a huge confirmation bias, because every success story is held up as "proof".  It also leads to cherry-picking, because anything not supporting the pole has to be ignored.  Those who advocate for those polarized positions must recognize that they are pulling everyone to the sides, where they may not belong. 

The same is true for diet and metabolism.  The reality is that we are dealing with complexity in physiology that can't be explained by one theory, and an obesity problem that does not have one solution.  Biological complexity dictates that what works for one will not work for another, and that's what coaches figure out very early with athletes, and dieticians learn empirically with clients.  The idea that shoes are bad is just as wrong as the idea that shoes are essential, because in any population, either could be true for some people.  These kinds of over-simplifications are damaging because they polarize understanding in a way that benefits few, introducing dogma that is then disseminated to the detriment of many.  And that is the point I make in the presentation above.

So, how is this relevant to diet?  Well, the same things I see from the barefoot debate appear to be happening in the dietary debate.  Conventional wisdom is challenged, and rapidly leads to the formation of two opposing camps, whose idealism is so at odds that the poor people in the middle, who are ultimately the "end users" of the information, are caught in a figurative stretching rack, being pulled in opposite directions by 'extremists'.  If it is difficult for experts to agree, then imagine how complex it becomes for those in the middle.

The problems at the poles

Science is never black and white.  It's one of the first lessons I learned, and have relearned weekly since.  Does dehydration impair performance and health? Is fatigue the result of chemicals in the muscle?  Is barefoot running safer?  Does cholesterol lead to heart disease?  There is no such thing as a straight-forward answer to any of these questions, and so a single extreme view is invariably wrong.  

It then becomes more about "how" the message is communicated, and not "what" is being said.  That is, the content of the deviant view almost always has value - the barefoot running concept, for example, may be incredibly helpful to many runners and I would strongly support that everyone take something from it.  On the other hand, there may be people who simply cannot succeed barefoot.   

What then tends to happen is that the polarized camps become almost obnoxious about their view, blaming everything but their view for the obvious failure to succeed 100% of the time.  If you are injured running barefoot, it's your fault, for instance, and its advocates seem to show no awareness that they are making exactly the same mistake as they accuse shoe companies of making before them.  It is that aspect of the debate that is most off-putting, and I find the same true in the carbohydrate debate.  The justification for a given position becomes more and more 'radical', and eventually, it is based on anecdotes, resembling a series of TV infomercials promising "more".  

Polarization also introduces a risk of weak scientific interpretation, and I've seen examples recently where an association study is dismissed as weak and unreliable when it suggests that carbs are important, only for the same type of association studies to be used as "proof" when they support the desired viewpoint a day later.

Ultimately, there is without doubt truth in any deviant view, but there is also a problem with the idea that the scientific pendulum should swing all the way from its current position to an entirely new one.  With respect to the carbohydrate debate, there is no question that Noakes has, like those advocating for it before him, contributed to many success stories and positive changes as a result of diet.  And by opening up the kind of debate you see below, he has potentially created enough "scientific anxiety" that it will stimulate a whole new area of research that will ultimately help advance our understanding of how INDIVIDUALS respond to different macro-nutrients, and hopefully reduce the obesity epidemic we face.

But in all this, and in debates about shoes vs barefoot running, and talent vs training, and methods of training and so on, don't feel compelled to pull the pendulum to the other extreme - remember, that's what you're suggesting others have done wrongly before!  There's no such thing as "we were 100% wrong before".  We just weren't 100% right, and it's the contribution of deviants who help us see that.  But stay away from the poles.

UCT Centenary Debate: the cholesterol debate

Right, so below is the debate.  It's one long video, divided into three chapters:

1. Prof Tim Noakes introduces his theory (35:43)
2. Prof Jacques Roussouw responds (43:21)
3. Questions and discussion with the audience (51:05, but probably the most interesting aspect)

To compliment the video, you may also want to view the presentations (it's not filmed very well, have to say):

View Prof Noakes' presentation
View Prof Roussouw's presentation

Feel free to comment and share your views.  Again, I'm not going into specifics, it just isn't my place and feels disrespectful to people who arguably know more than I do about this, but gladly debate the manner of the debate and the way ideas are communicated!

Ross

Long-term athlete development: Foundations & challenges

Long-term athlete development: Foundations and challenges for coaches, scientists & policy-makers

The Long-Term Athlete Development (LTAD) model is a physiological framework proposed to manage the focus, volume and type of training applied to athletes as they develop through adolescence into adulthood.  There remain a number of question marks against the foundations of LTAD, though it provides a sound framework for sporting development.  It does however introduce a number of practical challenges, and its success requires that coaches recognize the potential barriers and conflicts.  These are described below in a presentation and summary of LTAD.

- Ross Tucker

I'm currently in Dublin, at the invitation of the International Rugby Board, to present at their biennial Coach Education Workshop.  Topics include rugby safety/risk (as my tweet last night illustrated), the professionalization of coaching, Sevens rugby, and the topic for which I was invited, Long-Term Athlete Development (LTAD).

LTAD has become something of a staple for sports federations, coaches and administrators - in South Africa, there is a veritable alphabet of LT_Ds, including Athletes (LTAD), Participants (LTPD), Coaches (LTCD), with touted "Fs" (facilities), "Ms" (mentors)" and "Rs" (for resources) in the pipeline.

In any event, LTAD is an interesting starting point for discussion, and this is not exclusively for rugby coaches.  Of course, my talk was targeted at rugby, but the same conceptual framework has been applied to every sport, and it's worth debate between scientists, coaches and managers.  I take a rather strategic view of this - the specifics have been debated elsewhere, and I think the big picture matters more than the minute details.  It's a question of management strategy as much as it is science.

Below is my presentation.  Obviously, it lacks the narrative of me talking through it, but I hope that it makes at least some sense without it.  Once you've gone through it, I have included some thoughts below, in bullet point form, to sum up the key points regarding LTAD and the challenges facing its implementation.

Here is that presentation (If you are viewing this as an email, click here for the presentation):



Key points:  

Introduction

1. The purpose of any framework, be it LTAD or any other, is to drive the allocation of resources in an effective and efficient manner.  These resources, human, financial or structural, are finite, and the decision must be made about where to invest.  Talent ID for sport is a relatively simple question - it asks "Where is the athlete today, who will represent our country in 15 years' time?"  The simple question however has a complex answer, because we need to find him and then develop that potential talent.  That requires some important decisions about who does what within a sporting system?  How those resources are allocated is the crux of LTAD.
   
   
2. Talent Identification cannot be formulaic.  The biggest oversight or error is to view frameworks such as this as "formulas" for success.  Sporting success is multi-factorial, and too complex to obey a single formula.  As a result, we look in hindsight at what worked and create models to apply with foresight, but the mistake would be to become too prescriptive or literal.  For every rule, there are exceptions, which probably means there is no rule.
   
   The model of Vaeyens et al, presented above, explains the factors associated with sporting excellence.  "Giftedness" or innate abilities, along with chance, are recognized as a significant elements, and catalysts including environment and intra-personal characteristics are crucial.  Talent Identification and Talent Development contribute to optimizing these elements or catalysts.
   
   
3. Within a given sport, there exists a pipeline that takes young athletes to higher performance levels with age.  A number of questions need to be answered - how young and how old? How are resources applied? What role to coaches and competition play?  The volume of the "base" drives the required efficiency in order to achieve the same pinnacle.  The answer to these questions is proposed by the LTAD model of Balyi.  In the presentation, I depict a summary of the excellent Irish Rugby Football Union model, "Six to Six Nations".  A google search will reveal many other similar applications of LTAD for various sports
   
   LTAD: Foundations and concerns
4. LTAD divides the path from a child to a professional into a number of stages.  For each stage, the focus, the role of the coach and the responsibilities of the player vary.  In the Irish Model, and generally true of LTAD, serious competition is delayed until after adolescence.  This has repercussions for where the sport fits in within society, and the management of various stakeholders.  In fact, it is this balance between competition (which society demands) and the LTAD proposed delay in competition that is likely to be the source of most "tension", and thus failure, within the model.  This is explained later
   
   
5. While conceptually sound, it must be borne in mind that LTAD has not been conclusively proven.  Two of the foundations I discuss briefly in the presentation are the "Windows of opportunity" concept, and the 10,000 hour concept.
   
   Re the windows of opportunity, the issue is not so much that they do not exist (though there is some academic debate on this point), but rather the literal or wrongful interpretation of them to lead to neglecting other attributes.  In the presentation, I mention two examples of this - physical literacy and aerobic development.  For a more comprehensive review, see Ford et al.  This is a typical example of applying the concept as though it is a formula - the value is not in being specific, but in understanding principles.
   
   In this regard, there are three core concerns, which I explain in the presentation.  The first is that it can become too prescriptive.  Always remember that science loves averages and "typical" patterns, but not many individuals are average or typical.  As a result, if a coach tries to apply LTAD principles based on the average, there is a danger of "writing off" any young athlete who doesn't adapt, or obey the 'science'.  The second is that it's too literal, as explained.  And the third is that LTAD can become a real burden because of its extended period of responsibility for the coach or sport.
   
   Early exposure, relative age and 10,000 hours
6. It seems quite clear that early exposure is important, but if we select talent too early, we run the risk of making mistakes and voluntarily cutting our player pool down by an enormous amount.  The best illustration of this is the relative age effect, where coaches of young children confuse maturity with ability, and so when picking players for teams, make the error of picking relatively older players.  A large number of potentially great athletes are thus neglected and never receive opportunities reserved for those "lucky" enough to be born at the right time of year!
   
   This is a significant challenge for sports, and may require a rethink about 
1. The age at which we begin to select teams, and;
2. The level of coaching we provide to our best young players compared to those who don't quite make the cut - I'd argue that the best coaches should perhaps be allocated to the second best players at this age
   
   Having said this, there is some evidence that this relative age effect disappears in adults, which is really interesting, and may suggest that once you have early exposure, and once all the physical differences between early and late developers are ironed out, something else predicts long term success in sport.
   
   
7. The 10,000 hour concept for success, popularized by Gladwell in "Outliers" and Syed in "Bounce" has very little merit if applied literally to sporting success.  What it does do is provide a compelling argument that practice helps performance, but this is so obvious it doesn't really need to be said to a group of coaches!
   
   The 10,000 hour concept owes its existence to a study on violinists, by Ericsson, in which he found that the best players have accumulated 10,000 hours.  What he failed to do was any statistical analysis at all, and the result is that he didn't show that some people become best experts with less, and others fail despite doing more than 10,000 hours.  It took a study on chess players to reveal this - the average time taken to become a master is 11,000 hours, but some did it on 3,000 hours of practice, some haven't succeeded despite 25,000.  Those people effectively disprove the theory, and leave us realizing that a lot of practice is required to get good at things, but to commit to a specific number is a myth.  In fact, I'd go so far as to say that for a coach, one of the best methods of talent ID is to look for responsiveness to training.  If an athlete cannot acquire a new skill or adaptation rapidly, they're not going to become elite.
   
   Delayed high volumes of training predict success
8. Studies have shown that success in the CGS sports (sports where performance is measured in centimeters, grams or seconds) is related to a) delayed specialization, and b) delayed high volumes of training.  In other words, athletes who perform higher volumes of training when younger are less likely to become elite.  Those athletes who delay this increase succeed.  There are a number of possible explanations for this - one is burnout, in athletes who do more when younger.  The other is physiological, and this is the one I've explained in the presentation above.
   
   This is again an argument for delaying the identification and training of young athletes until after the physiological changes associated with adolescence are completed.  It is at 16, not 13, that talent ID and development become more effective.
   
   Physiological determinism and fate: the role of physiology/genes
9. In rugby, as in many sports, physiology plays a crucial role.  Even among a very good group of rugby players, who are the best in the country, there is a small but significant difference in stature and mass in those players who go on to become the very best (Springbok players).  In rowing, one of the more amazing findings I have seen in recent years, shows that elite female rowers have testosterone levels 112% higher than sub-elite female rowers.  One interpretation of this is that if you do NOT have testosterone levels in that range, then no amount of training, no LTAD and no development is going to make you elite - physiology determines your fate.  That's not to say that having high testosterone levels ensures success, but it is a crucial requirement.
   
   
10. Applying this to rugby, I look at the data of how many rugby players have played at the highest level in South Africa at the age of 13, the age of 16 and the age of 18.  Turns out that the conversion of good 13 year olds to good 16 year olds is relatively poor - only 31.5%.  From 16 to 18, it's much better - 76% of young players who play at U/16 level also play at U/18 level.
    
    Collectively, what this means is that if you are good enough to play at U/13 level, the chance that you'll make to U/18 level is basically 1 in 4.  Not too good.  If you make it to U/16 level, there's a 3 in 4 chance that you'll get to U/18 level.  Much better.
    
    This has the same significance as the relative age effect and the finding that delayed high volume predicts success - it says that the more you can delay the selection of talent, the more efficient your system.  What it does not do, more profoundly, is tell you the fate of all the players who were NOT selected at those younger age groups.
    
    The competition conflict - LTAD vs society's accepted norm
11. Attitudes to competition provide the greatest barrier to successfully implementing LTAD.  If the competition structure places any priority on winning at the junior level, then it directly conflicts with the fundamental of LTAD, which is to delay the importance of winning until after adolescence   In South Africa, we have a competition-driven system - compete at 13, compete at 16, compete at 18, and the best come through.  It has certainly produced excellent seniors, but may lack efficiency, and possibly, may be detrimental because it 'writes off' a good deal of talent at a young age.
    
    In this kind of competitive model, early maturation is encouraged, and bigger, stronger, faster players are rewarded at a young age.  They may simply be the early developers.  The result is that once differences are ironed out, they no longer possess an advantage, and the system 'pays' for neglecting those players who would've gone on to become equally large, strong and fast, but potentially with other attributes.
    
    Five key challenges
12. Given this reality, there are five key challenges facing LTAD:
1. How do you identify talent without either destroying it or neglecting it?  Talent is destroyed when it is chosen for the wrong reasons.  If you pick players at 13 based on size, speed and strength, you pick a temporary advantage.  But because it is rewarded by the competitive system, it never needs to develop other attributes.  Talent is neglected because late developers often do not receive a look in, and are lost to the sport early because of the way the system has been created.
   
   
2. How do you maintain healthy competition without providing a conflicting message to coaches?  You cannot create and implement LTAD which says "delay competition", and then have annual competitions for 10 or 13 year olds, the results of which are crucial to future success as a player.  That is a mixed message, and the coach will always go with performance.
   
   
3. How does a sport embracing LTAD affect that sport's standing in society?  The reality is that sport is a big deal, even from young ages.  Here in South Africa, high schools look for young children with athletic potential and offer scholarships and potential career paths.  At a young age, good athletes are virtually professional and society has come to accept this as "normal".  Implementing LTAD challenges that, and if the entire environment does not also do the same, then it creates a conflict between one sport and another, and even within a sport.
   
   For example, I work with SA Sevens, and we are looking at driving the specialization of players to become Sevens players from a younger age.  We are not going down to the 10-year olds, but it illustrates that because players themselves are finite, they are the subject of competition.  Imagine rugby implements LTAD and football does not - a good number of young players, perhaps forced by parents, will move towards football.  There is a degree of "security" in early specialization, however wrong that perception may be.
   
   
4. Who are the other stake-holders in LTAD?  It's simply not reasonable to suggest that one sport have an LTAD programme from 5 up to adulthood.  As mentioned, it's unnecessary because you don't need 10,000 hours to begin with, and it's also costly and potentially crippling to place the entire burden on each sport.  Therefore, you recognize that other stakeholders, such as parents and government, also play a crucial role, particularly early on when you actually don't want players to specialize, but rather engage in a number of different sports, learning a range of skills and abilities.  This is perhaps the key concept for LTAD.
   
   
5. How do we change mindsets?  In all of this, it's important to recognize that sporting systems, countries, federations, have a certain inertia.  They are giant, sometimes slow-moving bodies and if you stand in the way, you get flattened.  Therefore, to successfully implement LTAD, you must address the mindsets and begin to 'nudge' them in a different direction.  Failing this, LTAD, or any other similar plan, is nothing more than a fantasy of "best-case", and won't work in the real world.  It will take brave leadership to change the competition structure, for example, and to adopt a no compromise attitude towards youth talent ID and selection, based on current principles.  I doubt many will have the stomach for the fight, but that may be what it takes.
   
   Alternatively, we can accept a 25% success rate as good enough, which is fair.  But that cannot co-exist with excessive competition, as many of the rugby nations here in Dublin have discovered.

Conclusion

A sound concept, LTAD introduces a number of challenges at a system or management strategy level.  It also has some debatable physiological concepts, but the debate on those is perhaps too academic and thus not relevant for coaches.  It should not be taken too literally or prescriptively, but rather regarded as a framework to guide decisions.

The big picture is where it is far more complex.  Certainly, in South Africa, we will have to grapple with whether competition at young ages is the best way to achieve senior success, or whether it is worth the aggravation to change this.  There is no evidence, because there are no long-term prospective studies, that help us 'guess' how elite performance would change as a result of policy changes at the junior level.  However, it seems reasonable to hypothesize that if youth selection is delayed, and if the pool of available talent is kept large for long enough, we will see more viable prospective talents and thus better performance.

Coaching is often referred to a mix of art and science, and LTAD is similar.  There is no single path, and this is a debate likely to extend well into the future.  Feel free to weigh in below.

Ross

The War of the End of the World: The health puzzle posed by its survivors

The War of Canudos took place in Brazil in 1896 and 1897. Canudos was a settlement of several thousand deeply religious Christians, led by a man known as Antonio Conselheiro. They opposed the recent establishment of the Republic of Brazil, particularly the institution of income taxes and civil marriage; the former was considered government-sponsored theft and the latter a sacrilege. The republic had been declared in 1889 following a military coup that deposed Dom Pedro II, an emperor beloved by the common people and under whose rule slavery had recently been abolished.

Canudos was located in the Brazilian sertão, an inhospitable semi-arid region in the northeastern part of the country. The inhabitants of Canudos were the sertanejos. The term jagunço was used to refer to the males, especially the outlaws. Many of the sertanejos lived in semi-starvation, in poor sanitary conditions, and with very limited (if any) access to healthcare. Infant mortality was very high at the time. Those who reached adulthood were typically of small stature, and very thin; not lean, thin – often described as “skin and bones”.

Below is what a typical young jagunço would look like at the time of the War of Canudos. (Some authors differentiate between jagunços and cangaceiros based on small differences in cultural and dress traditions; e.g., the hat in the photo is typical of cangaceiros.) The jagunços tended to be the best fed among the sertanejos. They were also known as cold-blooded killers. The photo is a cropped version of the original one; the grizzly original is at the top of a recent blog post by Juan Pablo Dabove (). The blog post discusses Vargas Llosa’s historical fiction book based on the War of Canudos, the masterpiece titled “The War of the End of the World” ().

Jorge Mario Pedro Vargas Llosa, a Peruvian-Spanish writer and politician, was the recipient of the 2010 Nobel Prize in Literature; “The War of the End of the World” is considered one of his greatest literary achievements. Euclides da Cunha wrote the most famous non-fictional account on the War of Canudos, another masterpiece that has been called “Brazil’s greatest book”, titled “Rebellion in the Backlands” (). The Portughese title is “Os Sertões”. Vargas Llosa’s book is based on da Cunha’s.

Sergio Rezende’s movie, “Guerra de Canudos” (), is a superb dramatization of the War of Canudos. I watched this movie after reading Vargas Llosa’s and da Cunha’s books, and was struck by two things: (a) the outstanding performances, especially by José Wilker, Cláudia Abreu, Marieta Severo, and Paulo Betti; and (b) the striking resemblance of the latter (Betti) to Royce Gracie (), a very nice man whom I interviewed () for my book on compensatory adaptation (), and who is no stranger to Ultimate Fighting Championship and mixed martial arts fans ().

In a nutshell, the War of Canudos went more or less like this. There were four military campaigns against the settlement. The third was a major one, led by one of Brazil’s most accomplished military leaders at the time, Colonel Antônio Moreira César. The jagunços, resorting to guerrilla warfare, fought off the government troops in the first three. The fourth, led by General Arthur Oscar de Andrade Guimarães, saw the jagunços defeated in a war of attrition primarily due to lack of access to food and water, after heavy losses among government troops. At the end, nearly all of the surviving jagunços were executed, by knife – to their absolute horror, and the perverse pleasure of the executioners bent on revenge, as the victims believed that they would not go to heaven if their lives were ended by knife, even against their will.

Ned, what is your point regarding health!?

After going through numerous sources, paper-based and online, academic and non-academic, I am convinced that a significant number of the survivors of the Canudos War lived to their 90s and beyond. This conclusion is based chiefly on comparisons of various dates, especially of interviews with survivors. No single source dedicated to this particular health-related aspect of the War of Canudos seems to exist. There is a video clip that shows some of the survivors (), speaking in Portuguese, with their ages shown in subtitles (“years”, in Portuguese, is “anos”). One of them, a man, is listed as being a supercentenarian.

In modern USA those who live to the age of 90 and beyond are outliers. Less than 2 percent of the population reach the age of 90 (). Most of them are women. My impression is that among the survivors of the War of Canudos, the 90+ percentage was at least 5 times higher; even with access to sanitation and healthcare in modern USA being much better at any age.

If my impression is correct, how can it be explained?

I think that some of the readers of this blog will be tempted to explain the high longevity based on calorie restriction. But the empirical evidence suggests that poor nutrition, in terms of micronutrients and macronutrients, is associated with increased mortality, not the other way around (, , ). Mortality due to poor nutrition is frequently from infectious diseases, in the young and the old. Degenerative diseases are widespread among the overnourished, not the well nourished, and kill mostly at later ages. It is not uncommon for infectious diseases to “mask” as degenerative diseases – e.g., viral diabetes ().

Often people point at hunter-gatherer populations and argue that they are healthy because of their low calorie intake. But mortality from infectious diseases among hunter-gatherers is very high, particularly in children. Others point to the absence of industrial foods engineered for overconsumption, which I think is definitely a factor in terms of degenerative diseases. Some say that a main factor is retention of lean body mass as one ages, referring mostly to muscle tissue, a hypothesis to which the case of the sertanejos poses a problem – what lean body mass!? And, on top of all of their problems, the sertanejos regularly faced long droughts, which may be why they typically had a “dry” look.

Yet others point to low stress. It is reasonable to think that stress is a mediating factor in the development of many modern diseases. Still, the sertanejos living in Canudos have had to endure quite a lot of stress, before and after the War of Canudos. In fact, the depictions of their lives at around the time of the War of Canudos suggest very stressful, miserable lives, prior to the conflict; which in part explains the early success of a religious settlement where life was marginally better.

By the way, the traditional Okinawans have also endured plenty of stress (), and they have had the highest longevity rates in recorded history. Food scarcity has frequently been combined with stress in their case, as with many other long-living groups. Causality is complex here, probably changing direction in different subsets of the data, but I have long suspected that the combination of stress and overnourishment is a particular unnatural one, to which humans are badly maladapted.

A main factor is almost always forgotten: the effective immune systems of those who have been subjected to starvation, poor sanitation, lack of healthcare, and other challenges – especially in childhood – and survived to adulthood. And here some counterintuitive things can happen. For example, someone may be very sickly early in life and barely survive childhood, and then become very resistant to infectious diseases later, thus appearing to be very healthy, to the surprise of relatives and friends who remember “that sickly child”. Immunocompetence is something that the body builds up in response to exposure.

As they say in northeastern Brazil, in characteristic drawl: “Ol’ sihtaneju ain’t die easy”.