Selasa, 31 Mei 2011

Edinburgh: The final 3 minutes

The final 3 minutes from Edinburgh

It's here to stay, people, so enjoy it.  We have embedded this from Universal Sports, whose coverage of rugby is actually very good---so readers in the USA take note, they will be covering the Rugby World Cup later this year, too.  This is the best advertisement ever for the sport of Sevens.

These are those final three minutes:



Again, this is embedded directly from Universal Sports, so we should not have any problems with them blocking it from Youtube, which is where the other video was hosted.  At the risk of sounding like we are promoting it, you can even watch the reply of the entire SA vs. AUS match for $3.99, which is a pretty fair price.  Note to international readers, though---this content might only be available to those in the USA.  It kind of defeats the purpose, if you ask us, but perhaps there is a copyright or ownership issue they have to deal with!

Enjoy!

Senin, 30 Mei 2011

Interview with Jimmy Moore, and basics of intima-media thickness and plaque tests

Let me start this post by telling you that my interview with Jimmy Moore is coming up in about a week. Jimmy and I talk about evolution, statistics, and health – the main themes of this blog. We talk also about other things, and probably do not agree on everything. The interview was actually done a while ago, so I don’t remember exactly what we discussed.

From what I remember from mine and other interviews (I listen to Jimmy's podcasts regularly), I think I am the guest who has mentioned the most people during an interview – Gary Taubes, Chris Masterjohn, Carbsane, Petro (a.k.a., Peter “the Hyperlipid”), T. Colin Campbell, Denise Minger, Kurt Harris, Stephan Guyenet, Art De Vany, and a few others. What was I thinking?

In case you listen and wonder, my accent is a mix of Brazilian Portuguese, New Zealand English (where I am called “Need”), American English, and the dialect spoken in the “country” of Texas. The strongest influences are probably American English and Brazilian Portuguese.

Anyway, when medical doctors (MDs) look at someone’s lipid panel, one single number tends to draw their attention: the LDL cholesterol. That is essentially the amount of cholesterol in LDL particles.

One’s LDL cholesterol is a reflection of many factors, including: diet, amount of cholesterol produced by the liver, amount of cholesterol actually used by your body, amount of cholesterol recycled by the liver, and level of systemic inflammation. This number is usually calculated, and often very different from the number you get through a VAP test.

It is not uncommon for a high saturated fat diet to lead to a benign increase in LDL cholesterol. In this case the LDL particles will be large, which will also be reflected in a low “fasting triglycerides number” (lower than 70 mg/dl). While I say "benign" here, which implies a neutral effect on health, an increase in LDL cholesterol in this context may actually be health promoting.

Large LDL particles are less likely to cross the gaps in the endothelium, the thin layer of cells that lines the interior surface of blood vessels, and form atheromatous plaques.

Still, when an MD sees an LDL cholesterol higher than 100 mg/dl, more often than not he or she will tell you that it is bad news. Whether that is bad news or not is really speculation, even for high LDL numbers. A more reliable approach is to check one’s arteries directly. Interestingly, atheromatous plaques only form in arteries, not in veins.

The figure below (from: Novogen.com) shows a photomicrograph of carotid arteries from rabbits, which are very similar, qualitatively speaking, to those of humans. The meanings of the letters are: L = lumen; I = intima; M = media; and A = adventitia. The one on the right has significantly lower intima-media (I-M) thickness than the one on the left.


Atherosclerosis in humans tends to lead to an increase in I-M thickness; the I-M area being normally where atheromatous plaques grow. Aging also leads to an increase in I-M thickness. Typically one’s risk of premature death from cardiovascular complications correlates with one’s I-M thickness’ “distance” from that of low-risk individuals in the same sex and age group.

This notion has led to the coining of the term “vascular age”. For example, someone may be 30 years old, but have a vascular age of 80, meaning that his or her I-M thickness is that of an average 80-year-old. Conversely, someone may be 80 and have a vascular age of 30.

Nearly everybody’s I-M thickness goes up with age, even people who live to be 100 or more. Incidentally, this is true for average blood glucose levels as well. In long-living people they both go up slowly.

I-M thickness tests are noninvasive, based on external ultrasound, and often covered by health insurance. They take only a few minutes to conduct. Their reports provide information about one’s I-M thickness and its relative position in the same sex and age group, as well as the amount of deposited plaque. The latter is frequently provided as a bonus, since it can also be inferred with reasonable precision from the computer images generated via ultrasound.

Below is the top part of a typical I-M thickness test report (from: Sonosite.com). It shows a person’s average (or mean) I-M thickness; the red dot on the graph. The letter notations (A … E) are for reference groups. For the majority of the folks doing this test, the most important on this report are the thick and thin lines indicated as E, which are based on Aminbakhsh and Mancini’s (1999) study.


The reason why the thick and thin lines indicated as E are the most important for the majority of folks taking this test is that they are based on a study that provides one of the best reference ranges for people who are 45 and older, who are usually the ones getting their I-M thickness tested. Roughly speaking, if your red dot is above the thin line, you are at increased risk of cardiovascular disease.

Most people will fall in between the thick and thin lines. Those below the thick line (with the little blue triangles) are at very low risk, especially if they have little to no plaque. The person for whom this test was made is at very low risk. His red dot is below the thick line, when that line is extended to the little triangle indicated as D.

Below is the bottom part of the I-M thickness test report. The max I-M thickness score shown here tends to add little in terms of diagnosis to the mean score shown earlier. Here the most important part is the summary, under “Comments”. It says that the person has no plaque, and is at a lower risk of heart attack. If you do an I-M thickness test, your doctor will probably be able to tell you more about these results.


I like numbers, so I had an I-M thickness test done recently on me. When the doctor saw the results, which we discussed, he told me that he could guarantee two things: (1) I would die; and (2) but not of heart disease. MDs have an interesting sense of humor; just hang out with a group of them during a “happy hour” and you’ll see.

My red dot was below the thick line, and I had a plaque measurement of zero. I am 47 years old, eat about 1 lb of meat per day, and around 20 eggs per week - with the yolk. About half of the meat I eat comes from animal organs (mostly liver) and seafood. I eat organ meats about once a week, and seafood three times a week. This is an enormous amount of dietary cholesterol, by American diet standards. My saturated fat intake is also high by the same standards.

You can check the post on my transformation to see what I have been doing for years now, and some of the results in terms of levels of energy, disease, and body fat levels. Keep in mind that mine are essentially the results of a single-individual experiment; results that clearly contradict the lipid hypothesis. Still, they are also consistent with a lot of fairly reliable empirical research.

Epic Edinburgh and onto ACSM

Epic Edinburgh and onto ACSM:  Your suggestions...

I'm writing this from a train somewhere in the North east of England on my way down to London, having experienced a sensational week in Edinburgh.  It was mission accomplished as far as the first leg of my trip is concerned, though I'd be lying if I said it was business as usual - the mission had a great big "Impossible" stamped on it more than a few times, but our players did it and beat Australia to complete back-to-back wins in London and Edinburgh.

It took the most astonishing three minutes to achieve - an entire team entering the "zone" at the same time, to win a final against Australia where we were down 21- 7 at half-time, 28-7 shortly after half-time, and 35-19 with under three minutes remaining. 

What the scoreboard captures, a 36-35 win, tells nothing of the courage and heart it took for our players to stand up to an exceptional team, a huge challenge and what seemed a lost situation more than once.  We had only six healthy players, three players out completely, and three who should have been out had we been in the luxury position of giving them the rest they needed.  But they had to play through injuries,  and that kind of effort was possible only because the players understood that to transcend their limits, they had to have the higher purpose of carrying one another, playing for someone or something else.

I'd be lying if I said I knew we'd win it all along.  But it's not even a stretch if I tell you that in the changeroom minutes before the final, the team talk from two of the senior players on the team gave me the sense that anything was possible, that nine months of work had earned the players the privilege of seeing that higher purpose, the "WHY" behind the pain and hard work, and that is what ultimately allowed those final 4 minutes to happen.  Last week in London, it was all about the head - the tactical plan and the intelligence of the players to deliver.  This week, it was the heart, and one of the great performances. 

Later this week, I'm going to find (or make) a video of the final 4 minutes of the match, and put it here at some point in the next day or so.  I think for the sport of Sevens, and for Sevens in South Africa, those four minutes will be the most effective advertisements they will ever see.  I'll try to get that out as soon as possible, and hopefully it will survive on YouTube long enough to allow you to appreciate just how spectacular Sevens is as a sport.

Onto ACSM - looking ahead

But right now, my attention switches to the American College of Sports Medicine meeting in Denver.  It starts on Tuesday, and I present at a highlighted symposium called "Pacing Strategy:  A window into the experience of fatigue".  That happens next Friday at 1pm, and features our friends Carl Foster and Jos de Koning, along with Markus Amann and Romain Meeusen.

There is a strong focus on health and physical activity this year - the two big keynote lectures deal with diabetes, obesity and health policy.  I have an eight-hour flight from London to work through the programme, and I'll pick out the session that I'll be attending, but I'd love to hear from you about talks that grab your attention.

So check out the Advance Programme here, and if you see anything that sounds especially interesting, let me know - obviously, I can't be in 15 places at once, which is always a problem at these big meetings, but I'll do my best to get along and hear what the experts have to say in order to get some feedback to you! 

Until Denver (or that Sevens video)
Ross

Rabu, 25 Mei 2011

Edinburgh and ACSM: the journey begins

Edinburgh Sevens and the American College of Sports Medicine

I am writing this from the departure gate of flight 234 to London, which, ash-cloud willing, will carry me to London tomorrow.  There, I catch a train to Edinburgh where I will be linking up with the SA Sevens rugby team for the weekend's tournament, the last of the 2011 season.

Then on Tuesday, I fly to Denver for the American College of Sports Medicine's annual meeting.  I am presenting on Friday 3rd, in a highlighted symposium on Pacing Strategy and Fatigue.  That meeting lasts four days and is the most concentrated gathering of sports science in the world, so they will be a full four days.

Time will therefore be tight, and so doing longer posts here on the site is unlikely.  However, that's the reason we've set up a new Facebook page, and also our Twitter account, so that we can keep the Science of Sport going through links, brief opinions and some discussion.

While in Edinburgh and at ACSM, I will do my best to post on the Facebook site as regularly as I can.  Interesting studies, practical application, some thought and opinion.  Same goes for Twitter.

So if you have not already done so, jump onto our Facebook Fan Page and "like" it now, and you'll be in the loop from Denver and Scotland.  Our Twitter feed can be found here, where I link to things like articles of the week, news pieces on current affairs and so forth!

As always, we welcome dialouge, and so if you are in Denver, of if you like the look of any of the sessions at ACSM, let me know and I'll see what I can report back on!

Take care, and see you on the social media!

Ross

Senin, 23 Mei 2011

The China Study II: Wheat may not be so bad if you eat 221 g or more of animal food daily

In previous posts on this blog covering the China Study II data we’ve looked at the competing effects of various foods, including wheat and animal foods. Unfortunately we have had to stick to the broad group categories available from the specific data subset used; e.g., animal foods, instead of categories of animal foods such as dairy, seafood, and beef. This is still a problem, until I can find the time to get more of the China Study II data in a format that can be reliably used for multivariate analyses.

What we haven’t done yet, however, is to look at moderating effects. And that is something we can do now.  A moderating effect is the effect of a variable on the effect of another variable on a third. Sounds complicated, but WarpPLS makes it very easy to test moderating effects. All you have to do is to make a variable (e.g., animal food intake) point at a direct link (e.g., between wheat flour intake and mortality). The moderating effect is shown on the graph as a dashed arrow going from a variable to a link between two variables.

The graph below shows the results of an analysis where animal food intake (Afoods) is hypothesized to moderate the effects of wheat flour intake (Wheat) on mortality in the 35 to 69 age range (Mor35_69) and mortality in the 70 to 79 age range (Mor70_79). A basic linear algorithm was used, whereby standardized partial regression coefficients, both moderating and direct, are calculated based on the equations of best-fitting lines.


From the graph above we can tell that wheat flour intake increases mortality significantly in both age ranges; in the 35 to 69 age range (beta=0.17, P=0.05), and in the 70 to 79 age range (beta=0.24, P=0.01). This is a finding that we have seen before on previous posts, and that has been one of the main findings of Denise Minger’s analysis of the China Study data. Denise and I used different data subsets and analysis methods, and reached essentially the same results.

But here is what is interesting about the moderating effects analysis results summarized on the graph above. They suggest that animal food intake significantly reduces the negative effect of wheat flour consumption on mortality in the 70 to 79 age range (beta=-0.22, P<0.01). This is a relatively strong moderating effect. The moderating effect of animal food intake is not significant for the 35 to 69 age range (beta=-0.00, P=0.50); the beta here is negative but very low, suggesting a very weak protective effect.

Below are two standardized plots showing the relationships between wheat flour intake and mortality in the 70 to 79 age range when animal food intake is low (left plot) and high (right plot). As you can see, the best-fitting line is flat on the right plot, meaning that wheat flour intake has no effect on mortality in the 70 to 79 age range when animal food intake is high. When animal food intake is low (left plot), the effect of wheat flour intake on mortality in this range is significant; its strength is indicated by the upward slope of the best-fitting line.


What these results seem to be telling us is that wheat flour consumption contributes to early death for several people, perhaps those who are most sensitive or intolerant to wheat. These people are represented in the variable measuring mortality in the 35 to 69 age range, and not in the 70 to 79 age range, since they died before reaching the age of 70.

Those in the 70 to 79 age range may be the least sensitive ones, and for whom animal food intake seems to be protective. But only if animal food intake is above a certain level. This is not a ringing endorsement of wheat, but certainly helps explain wheat consumption in long-living groups around the world, including the French.

How much animal food does it take for the protective effect to be observed? In the China Study II sample, it is about 221 g/day or more. That is approximately the intake level above which the relationship between wheat flour intake and mortality in the 70 to 79 age range becomes statistically indistinguishable from zero. That is a little less than ½ lb, or 7.9 oz, of animal food intake per day.

Jumat, 20 Mei 2011

Tyler Hamilton: Confessor and witness

Hamilton admits to seeing Armstrong inject EPO

Many months have past with no news from the federal investigation into whether or not Lance Armstrong used performance-enhancing drugs.  Now, on Thursday evening, suddenly another bomb shell along the lines of Floyd Landis' admissions and allegations last year during the Tour of California.  

Tyler Hamilton, who rode with the US Postal Service team from 1998-2001, was interviewed by "60 Minutes."  The full interview will air on Sunday night, but the CBS Evening News on Thursday ran a short clip from it:


Corroboration or duplicity?  You be the judge

Not so surprising was the response from Armstrong's attorneys, who have chosen to stick to the tactic of assassinating the messenger.  According to them, Hamilton has "duped the CBS Evening News, 60 Minutes and Scott Pelley all in one fell swoop."  But the hyperbole does not stop there.  Now the language around Armstrong's never failing a test is "500 tests over 20 years of competition."  We have seen the number of times he has been tested discussed in the discussion board in other places, and the math is always a bit fuzzy.  The number always seemed to change and is seemingly a gross overestimate each time.  

This time around the number is 500 over 20 years. . .so an average of 25 times per year.  Except that by our calculations he did not compete for 20 years, and instead the number is closer to 16-17 years, and only if we include his amateur racing days:

1990-91:  Subaru
1992-96:  Motorola
1998-2005:  US Postal
2009:  Astana
2010:  RadioShack

And does anyone here believe that any pro cyclist was tested up to 25 times per year in the 1990s?  Or how about US amateurs in 1990-91?  But especially a rider like Lance Armstrong prior to 1999, when he was a mid-pack racer with mediocre palmares, excluding his 1993 World Championship?  It's classic "messaging" to keep the message on something else other than the allegations.  It begs the question of who is doing the duping, Hamilton or Armstrong's attorneys.

Hamilton also alleges that Armstrong admitted to him that he failed a drug test during the 2001 Tour de Suisse, an allegation we first heard from Landis last year.  The problem is that Landis' allegation has been public for a year now, so until more details come out about that specific event between Hamilton and Armstrong, that allegation remains an easy target for Armstrong proponents.  

Hamilton confesses

In a letter meant for what appears to be family and close friends but published on Cyclingnews.com, Hamilton confesses to his own doping.  And the thing that stands out in Hamilton's confession as well as Landis' from last year, is that these guys are burdened by the lies and deceit.  As well they should be, because they are not trained to live lies and keep a clear conscience.  There is such a profession for that, however---covert operatives in the CIA live double lives for years and years with no apparently ill consequences of it.  The athletes, though, are not trained to do that.  It requires a special personality type and skill set, and the cyclists are trained to race and compete, not to hoard secrets and live a lie.  Until we start a "Psychology of Sport" site, all we can say is the the psychology here is complex.  The Sports Psychologists and others can please chime in here with their comments, but for now we will leave the psycho-analysis at that.

Predictable reaction?

The reactions from the peleton will likely be two dimensional, with riders either condemning the liars and deceivers Landis and Hamilton, saying the past is the past, or those agreeing there is a problem but that now we are really making progress.  Or will it?  One has to wonder  if admissions by first Landis and now Hamilton will show others that it is ok to speak up?  The optimists out there will hold out that eventually the tide will turn, and we reach that "tipping point" when it now becomes acceptable to speak out.  It is anyone's guess what will happen after that, except at least those riders might be unburdened from any guilt they carry within themselves.

For now we will measure the fall out, if any, of this latest turn in the ongoing saga.  With the action heating up in the Giro and the Tour of California, all eyes should be on the racing, but yet again cycling cannot shake the doping issue.

Selasa, 17 Mei 2011


Sammy Wanjiru
November 10, 1986 - May 16, 2011




Sad day for running and runners everywhere

While watching the Chicago Bulls dismantle the Miami Heat in the NBA Eastern Conference Finals, I received the sad and shocking news that Sammy Wanjiru, 2008 Olympic Marathon Champion and one of greatest marathoners ever, has died in Kenya, aged 24.  

The initial details seem to indicate either a fall or jump from a balcony at his home in Kenya, resulting in injuries from which he could not be revived.  This much as been confirmed by his manager Fredico Rosa.

Wanjiru was an incredible talent, and had an aggressive racing style that may well have produced a world record given enough racing in the right circumstances.  He was never afraid to push the pace, both early and often, in the big races.  His marathon CV is simply astonishing, perhaps the best ever, as outlined in this obit piece by Letsrun.com

Sevens races and five wins, including London, the Olympics and Chicago.  But two performances stand out, perhaps two of the great marathons in recent memory.  

First, the Beijing Olympic marathon was without doubt one of the great performances ever seen.  Unaided by pace-makers, Wanjiru attacked repeatedly off a fast tempo, in hot, humid conditions and absolutely destroyed the world's best over the second half of the race, running 2:06:32.  That time in the heat and humidity of Beijing is simply breath-taking.  That he was able to put almost a minute into second place, and almost four minutes into the rest of the world class field is a sign of an astonishing performance


Then in Chicago last year, he and Kebede produced the race of the year - a marathon that resembled a bicycle race, it was so full of surges and counter-surges in the final few kilometers.  Many times it seemed that Kebede had him beaten, but Wanjiru hung on and eventually found the most brutal surge of all to win the race, and the World Marathon Major title.  That race typified Wanjiru - brave, brutal and full of heart. 

Unfortunately Wanjiru's racing strategy was so aggressive that it probably reduced his chances for a record, but it produced the kind of head to head, fascinating battles that the sport needed.  What is the pack to do when a runner like Wanjiru surges so early?  Let him go?  Never, because he was too much of a threat to hang on for a win even if he melted down and limped across the line. 

Perhaps with maturity we could have seen some refinement of his pacing strategy and a record, although sadly now that will never come to pass.

Recently Wanjiru made headlines for a domestic dispute with his wife in which he pulled a gun on her and was charged with attempted  murder.  That case was resolved favourably for Wanjiru, but considering that those events happened, we could at least assume that not all was well in his personal life.  We all have personal demons, and it appears as though Wanjiru's might have gotten the best of him.  

This is a sad reminder of the transience of life and talent.  Wanjiru was indestructible on the roads, but unfortunately, his personal life reminds us that this did not apply elsewhere.  Sammy Wanjiru was a racing genius, a man who shook the world of marathon running, and we are all shaken once again by his tragic death.

We will all have to wait as official reports come in that hopefully will reveal more details about the circumstances around his death.  For now, we will just say rest in peace, Sammy.  The running world will miss you.






Senin, 16 Mei 2011

Book review: Biology for Bodybuilders

The photos below show Doug Miller and his wife, Stephanie Miller. Doug is one of the most successful natural bodybuilders in the U.S.A. today. He is also a manager at an economics consulting firm and an entrepreneur. As if these were not enough, now he can add book author to his list of accomplishments. His book, Biology for Bodybuilders, has just been published.

(Source: www.dougmillerpro.com)

Doug studied biochemistry, molecular biology, and economics at the undergraduate level. His co-authors are Glenn Ellmers and Kevin Fontaine. Glenn is a regular commenter on this blog, a professional writer, and a certified Strength and Conditioning Specialist. Dr. Fontaine is an Associate Professor at the Johns Hopkins University’s School of Medicine and Bloomberg School of Public Health.

Biology for Bodybuilders is written in the first person by Doug, which is one of the appealing aspects of the book. This also allows Doug to say that his co-authors disagree with him sometimes, even as he outlines what works for him. Both Glenn and Kevin are described as following Paleolithic dieting approaches. Doug follows a more old school bodybuilding approach to dieting – e.g., he eats grains, and has multiple balanced meals everyday.

This relaxed approach to team writing neutralizes criticism from those who do not agree with Doug, at least to a certain extent. Maybe it was done on purpose; a smart idea. For example, I do not agree with everything Doug says in the book, but neither do Doug’s co-authors, by his own admission. Still, one thing we all have to agree with – from a competitive sports perspective, no one can question success.

At less than 120 pages, the book is certainly not encyclopedic, but it is quite packed with details about human physiology and metabolism for a book of this size. The scientific details are delivered in a direct and simple manner, through what I would describe as very good writing.

Doug has interesting ideas on how to push his limits as a bodybuilder. For example, he likes to train for muscle hypertrophy at around 20-30 lbs above his contest weight. Also, he likes to exercise at high repetition ranges, which many believe is not optimal for muscle growth. He does that even for mass building exercises, such as the deadlift. In this video he deadlifts 405 lbs for 27 repetitions.

Here it is important to point out that whether one is working out in the anaerobic range, which is where muscle hypertrophy tends to be maximized, is defined not by the number of repetitions but by the number of seconds a muscle group is placed under stress. The anaerobic range goes from around 20 to 120 seconds. If one does many repetitions, but does them fast, he or she will be in the anaerobic range. Incidentally, this is the range of strength training at which glycogen depletion is maximized.

I am not a bodybuilder, nor do I plan on becoming one, but I do admire athletes that excel in narrow sports. Also, I strongly believe in the health-promoting effects of moderate glycogen-depleting exercise, which includes strength training and sprints. Perhaps what top athletes like Doug do is not exactly optimal for long-term health, but it certainly beats sedentary behavior hands down. Or maybe top athletes will live long and healthy lives because the genetic makeup that allows them to be successful athletes is also conducive to great health.

In this respect, however, Doug is one of the people who have gotten the closest to convincing me that genes do not influence so much what one can achieve as a bodybuilder. In the book he shows a photo of himself at age 18, when he apparently weighed not much more than 135 lbs. Now, in his early 30s, he weighs 210-225 lbs during the offseason, at a height of 5'9". He has achieved this without taking steroids. Maybe he is a good example of compensatory adaptation, where obstacles lead to success.

If you are interested in natural bodybuilding, and/or the biology behind it, this book is highly recommended!

Sabtu, 14 Mei 2011

The UCI's Suspicion score


The suspicion score: UCI rankings leaked, published and debated

I'm pretty sure that by now, most of you have read the following news, in which L'Equipe has obtained a confidential document from the UCI in which all the riders in the 2010 Tour de France have been scored on a scale from 0 to 10 based on their biological passport data (I've copied the full list from this article and pasted it at the end of this post)

On the scale, 0 means no suspicion of doping - a rider with an extremely clean passport record.  Scores between 6 and 10 apparently imply a high degree of circumstantial evidence because of large fluctuations in the passport data.

Not surprisingly, the reaction from the cycling world has been angry, with the UCI condemning the leak and the riders reacting angrily to both the leak and the fact that they're being rated on some kind of suspicion scale.

But let's cut through the expected emotive reactions and look at some of the issues behind the story.

The first point is that the leak and the fact that riders are being rated on a suspicion scale are two unrelated events.  That is, the fact that there is a leak should be condemned, mostly because it's a symptom of an organization that doesn't have it's house in order.  And a leak has some far-reaching implications, in that it undermines the trust that biological passport system relies on.  So that is certainly a concern for those involved in the fight against doping.

But the fact that riders are being ranked on this scale is a separate issue.  It may even be commended, depending on how it is done, but the leak has created confusion and speculation which shouldn't be confused with the actual concept of rating riders (a practice that certainly can be debated).

The rating concept is an issue that has people asking some very pertinent questions:  "How is the score calculated? What are the UCI doing with the scores? How can a rider be suspicious and not simply positive or negative? Are they targeting testing based on the ratings?  Is this fair?".

For the answers to these questions, let's go back to go forward.

The biological passport concept

We've said a fair amount on the biological passport in 2011, most of it very positive.  If you missed those pieces, I'd encourage you to read them here:
  1. The legal, scientific and performance viewpoint of the biological passport
  2. Evidence that the biological passport IS proving effective in the fight against doping
Without wishing to rehash those (lengthy) posts, a summary is important because it sets the context for why a rating system is part of the control and policing of the passport system.  First, the passport is a very stringently designed scientific tool.  It has the backing of substantial research, some of which we discussed in that first post on the legal issues.  It's not perfect, and of course more research is needed, but it's not a stab in the dark at catching dopers.

Now you may recall that in order for the biological passport to be legally acceptable, it has to have a very low risk of producing "false positive" results.  And false positives do happen, because you are looking for abnormal variations in a biological system that has natural variation to begin with.

And so what has been done is to set a limit of probability that allows 99.9% confidence that a a value (for reticulocytes, hemoglobin or off-score) lies outside the 'normal' range.  All measurements are analysed using software to answer the question "what is the probability of finding these values in an undoped sample?"  Only when a value lies outside this 99.9% confidence limit does it constitute a 'strike'.

That's the first line of defense against unfairly pursuing doping cases.  The second is that a rider is not sanctioned on a once-off strike.  A case is only opened if several different variables are beyond these boundaries on more than one occasion.

If this happens, then a third layer is that a team of experts evaluate and analyze the values.  If they feel that the profile is typical for a certain doping intervention, the athlete is contacted and questioned about potential reasons for his values. His justifications are again evaluated by the experts.  Only if they are still convinced that the profile is typical of doping and is not caused by the explanations put forward by the athlete (as has happened for Pellizotti and Valjevic), do they suggest the opening of a procedure against the athlete.

Legal clout, but expanding the impact of the passport through ranking the "near strikes"

So quite clearly, by the time a case is opened, there is already high certainty that doping is taking place - that's why three out of three cases that have gone to the CAS have been won by cycling.  This is a fantastic boost for the passport, because the stringency and strength of the system has been affirmed at the highest level.

This strength and "legal clout" comes from the high probability limit of 99.9%, which means that false positives will happen only once in a 1000 samples.  This is essential, because it must protect riders against false accusation.  The "problem" is that it also sets the bar so high that a lot of sample that are doped will perhaps fall into a 99% confidence limit, or even a 95% confidence limit, and thus not counted as strikes.  The legal requirement is a "conservative system", which doesn't necessarily ensure maximum impact on doping.
 
In other words, at say 95%, a sample would be suspicious and indicative of doping, but not legally enforceable, because you could get a false positive once every 20 measurements.  But that cyclist may still be doping and if they repeatedly produce these kinds of measurements, then these "near-strikes" also need to be accounted for. And this, I suspect, is how the rating system works.

A justified process of control and one way of implementing the passport

Now, this is speculative, because we simply don't know that this is the basis for those scores.  However, for the sake of illustration, this is how I would use a rating system: Consider a rider whose measurements would produce a 'strike' at a 99% confidence level, but not 99.9%.  The first such occurrence may be worth a score of 1.  If that same rider repeatedly 'strikes' at this lower probability level, he accumulates more points.  These points could be scaled afterwards by some correction factor to produce the 11-point scale (0 to 10) that was used, and there's the value you see in the lists below.

Our rider never exceeds a 99.9% confidence level, and so quite rightly, a case can't be opened, but he's been identified as a suspicious rider based on a long sequence of unusual values that lie on the border of being strikes.  The more often he is flagged with a near strike, the higher his score, which is reasonable.  And I believe it is entirely justified to watch this rider more closely.  Why?  Because we know from testimony that riders are able to manipulate their blood values through masking with EPO and by micro-dosing, and so it's quite conceivable that the precision of doping allows riders to stay beneath a 99.9% "radar" but not the 99%.

"Too normal" - sometimes variation is good

The other interesting possibility, mentioned in the L'Equipe report, is that some riders are suspicious precisely because they are "too normal".  That is, variation in blood markers is supposed to happen, and when it does not, then that too is a flag, and so is part of the designation of what constitutes suspicious.  I'm not sure how this is incorporated into a score, but it's hopefully understandable that if a rider presents with "perfect" values time after time, that's as much a problem as wild fluctuations outside the limits.

The fact that he is then rated on a scale, receiving a value of say 4 or 5, is simply part of the management of such a system.  In my opinion, this is entirely justified and acceptable.  It is part of the effective implementation of a passport system, which would lose much of its "bite" if there was not some avenue to monitor and target testing of riders who did not hit the 99.9% level.

The fact that these scores are now public knowledge, without necessarily explaining where the number comes from, that's the problem, for the following reasons:
  1. The possibility of subjective scoring and generalization

    Honestly, in the immediate aftermath of seeing that list, did you look at some cyclists and say "Ha, I knew it!  Doper!", or did you look at some names and scores and say "No way is Rider X more suspicious than Rider Y!"?  Because if you did, then you were, at least partly, comparing riders based on subjective perceptions of guilt and innocence! 

    The problem is that it's quite possible that whoever developed those rankings did so objectively, but with some subjective moderation, and that would not be a good thing.  If the rating is developed solely on the basis of biological passport measurements (as we are led to believe by the L'Equipe article), then I'd be satisfied.  But if it is subjectively moderated, then that may be an issue. 

    An extension of this is that once public, then the scores can further re-inforce stereotypes about certain teams or riders.  For example, L'Equipe took the step of using the UCI scores to calculate  which teams and nationalities were most suspicious.  In what some will describe as 'vindication', it turns out that Astana and Radioshack are the most suspicious teams, and Russia, Ukraine and Kazhakstahn are most suspicious nations.  I'm reminded that sometimes, stereotypes exist because they're true - sometimes, reputations are earned and deserved.  But one can sympathize with the rider from these teams/countries who is NOT a doper, but is now implicated by association and generalization, which would be unfair.

    For the public, the subjective perception will always feature, but what a leak does is allow confusion, and confusion allows more subjectivity and generalization.
     
  2. Uncertainty over the relative rankings and scaling

    How is a rating of 8 different from a rating of 4?  How close to a doping sanction is a guy who scores 9?  Is a score of 3 supposed to be interpreted as possible doping, likely innocence or neither?  Does the score actually have any doping relevance?  For one thing, it doesn't mean that the rider who scores 8 is doping twice as much as the rider scoring 4.  It doesn't mean he is twice as likely to be doping either.  The truth could well be the other way around, but it's just that the one is smarter at avoiding larger changes in bio-passport data.  But the problem is that by the time you get to 9 or 10, then that rider is so strongly suspected that a lot of people would be wondering why he isn't just sanctioned.  Or why the rider who scores 5 (Contador) is caught whereas riders who score 9 or 10 (Menchov, Popovych) are not caught?  Hopefully, in my short summary above, and in this previous post, I've explained why bringing a legal case has a more stringent requirement than being suspected.

    I've also given my illustration of how the bio-passport MIGHT be used to create these scores, by combining 'near-strikes' according to an objective criteria with the number of times they occur.  The cyclist scoring 8 or 9 might have produced 9 suspicious values at a probability limit of 99%, but not one at 99.9%.  Of course, this is speculative, which is why a leak undermines the credibility of the process, because it invites speculation.

  3. The witch-hunt phenomenon

    The third point, very relevant, is that this kind of scoring (independent of it being leaked) will lead to a witch-hunt, where some riders will be targeted for testing.  I actually don't have a problem with this, provided that the classification of riders is done objectively using solid science (see point 1).  I will concede that some cyclists may be targeted unfairly, perhaps based on their reputation or allegations.  But honestly, I don't even have a problem with this, as long as it's not prejudicial to the rider's participation (that is, cases are opened unfairly).

    But that doesn't seem to be the case - every case opened so far has been won.  The expertise behind the passport is world class (even if the management and administration by the UCI is not - see the leak as Exhibit A), and so I'm confident that targeted testing is not a witch-hunt, but a more cost-effective and intelligent way to weed dopers out.  It's much like the sniper approach compared to the machine gun approach - if finances are limited, then rather spend the money where it may be most effective, and that is part of the value of the passport.

    Incidentally, targeted testing has helped catch dope cheats before - Ricco was suspected for a long time and targeted for testing before eventually being caught, and so there is definitely merit.  I guess the key question here is what do you actually do with a rider who is targeted?  By definition, the fact that he is suspicious and not positive means that you'll never be able to bring a case against him unless he slips up.  And perhaps more frequent testing for the higher rated cyclists will improve the chances of catching these slip-ups.  That's one way of focusing testing.  This kind of focus saves money, and as long as the process is objective and fair, and not played out unnecessarily in public, then I think they're positive.  But I accept that some may disagree.

    The other thing that is really interesting to consider is that some cyclists may be better than others as disguising doping.  Now, because of this leak, cheaters who are better at manipulating their values look squeaky clean, and have this rating as their defense, when in fact, all they are is more effective at doping!  That's part of the reason why linking names to scores may not be ideal, and certainly why a leak doesn't help because we lack the context to fully understand how the score is derived.

    As an aside, it is interesting to note that last year, during the Tour, a lot of the riders who were rated 8 or higher were NOT tested (as raised by an independent WADA Report) - this point is raised by Festinagirl in the comments section below, and it again opens the UCI to alleged favouritism as a result of lax testing.  If the point of this rating system is to target testing, then testing had better reflect it. If it doesn't, well, what's the point of the scores?  Too much unanswered.
Fascinating insight into the process, but have we moved backwards?

I'd be lying if I said the scores were not fascinating to see.  I've often argued for full transparency in anti-doping efforts, that the bio-passport values should be made available (as some promised to do but never did).  Seeing the rankings of riders is about as transparent as it gets, but the confusion and uncertainty over exactly what the scores mean and how they're used means one step forward for transparency, one step backward for improved knowledge!  And perhaps most worryingly of all, two steps back for trust and credibility of the whole anti-doping effort.

So perhaps the scores might have been made available without the associated names.  Revealing that riders are rated, and telling us that say 50% of the riders have a score of 4 or higher would send the same message to the professional peloton that they are being watched as publishing names.

As mentioned at the outset, linking the names with the scores only undermines credibility of the system, and the system is so reliant on the trust of anonymous analysis of blood values.  It also provides a convenient public defense to some riders who may not necessarily be innocent, and possibly disadvantages riders who may be innocent but now have high index scores.

The reality is that putting names to the biological passport should be done only in the very final step of the process - the leak has given us an insight into the process, but perhaps the same effect might have been achieved without the risk to the credibility and trust within the between rider and tester.

Intriguing insights into the UCI, the leak, and conflicts of interest

As for the UCI, there are signs, in one respect, that they are trying to enforce a biological passport system that I believe is already effective and continues to "scare" riders into less doping, if not eradicate it completely.  This leak will heighten that 'fear', reminding the riders that even negative tests don't mean they're not under the spotlight.

But the UCI's reaction, combined with other UCI anti-doping actions only provides more fodder for critical of the UCI.  For one thing, the leak undermines the credibility of an organization that can't seem to sort out its own internal processes.  One of the key requirements of a successful anti-doping programme is trust - every party must trust the others to be fair and accurate in their actions and a leak like this undermines that trust.  The UCI already has this clandestine reputation, and this doesn't help.

It also doesn't help when the UCI can't reach agreements over testing at races and ends up marginalizing independent organizations, as happened for the upcoming Tour of California.  Rather than having independent and comprehensive testing from USADA, Bonnie Ford reports that the UCI will now handle the testing, which further increases the perception that the UCI are hiding something, giving preferential treatment to certain teams and riders, and generally having an enormous conflict of interest.

When the UCI deplore the leak and publication of their suspicion scores, and follow this up a day later by marginalizing independent testing authorities as a result of unwillingness to make available test results or allow targeted testing, it only reinforces the perception of a clandestine approach.  Perhaps full transparency is the way to go - but not for the first time, it's the media who have forced it onto the UCI, who continue to send mixed signals about anti-doping efforts.

Difficult times for cycling.  And all the while, a bike race goes ahead in Italy, but it's anti-doping on the back pages.  

Ross

And finally, here is the complete list:

0 Mario Aerts, Yukiya Arashiro, Stephane Augé, Michael Barry, Francesco Bellotti, Jose Alberto Benitez, Edvald Boasson Hagen, Lars Boom, Maxime Bouet, Pavel Brutt, Fabian Cancellara, Manuel Cardoso, Dries Devenyns, Samuel Dumoulin, Julien El Farès, Simon Gerrans, Anthony Geslin, Bert Grabsch, Christopher Horner, Robert Hunter, Kristjan Koren, Burt Lancaster, David Le Lay, Christophe Le Mével, Adriano Malori, Koes Moerenhout, Amael Moinard, Lloyd Mondory, Damien Monier, Juan Jose Oroz, Remi Pauriol, Mathieu Perget, Gregory Rast, Mark Renshaw, Nicolas Roche, Jurgen Roelandts, Pierre Rolland, Anthony Roux, Jeremy Roy, Mathieu Sprick, Rein Taaramae, Sebastien Turgot, Niki Terpstra, Brian Vandborg, Kristof Vandewalle, Ivan Velasco, Thomas Voeckler, Fabian Wegmann, David Zabriskie

1 Marcus Burghardt, Sandy Casar, Anthony Charteau, Sylvain Chavanel, Julian Dean, Mickael Delage, Martin Elmiger, Johannes Fröhlinger, Jakob Fuglsang, Robert Gesink, Xavier Florencio, Adam Hansen, Ryder Hesjedal, George Hincapie, Andreas Klier, Roger Kluge, Alexander Kuchinsky, Daniel Lloyd, Mirco Lorenzetto, Martijn Maaskant, Aitor Pérez, Alan Pérez, Jerome Pineau, Ruben Plaza, Alexandre Pliuschin, MaartenTjallingii, Rafael Valls, Maarten Wynants

2 Eros Capecchi, Mark Cavendish, Stephen Cummings, Remy Di Gregorio, Arkaitz Duran, Mathias Frank, Oscar Freire, John Gadret, Francesco Gavazzi, Volodymir Gustov, Thor Hushovd, Christophe Kern, Thomas Löfkvist, Sebastien Minard, Daniel Navarro, Grischa Niermann, Stuart O'Grady, Rubén Pérez, Christophe Riblon, Thomas Rohregger, L. L. Sanchez, Carlos Sastre, Fränk Schleck, Simon Spilak, Bram Tankink, Stijn Vandenbergh, Benoit Vaugrenard, Jens Voigt, Eduard Vorganov

3 Ivan Basso, Grega Bole, Brent Bookwalter, Dimitri Champion, Gerald Ciolek, Rui Costa, Damiano Cunego, Mauro Da Dalto, Francis De Greef, Markus Eibegger, Imanol Erviti, Tyler Farrar, Fabio Felline, Juan Antonio Flecha, Maxim Iglinskiy, Vasil Kiryienka, Roman Kreuziger, Matthieu Ladagnous, Robbie McEwen, Maxime Monfort, Sergio Paulinho, Joaquin Rodriguez, Andy Schleck, Chris Anker Sörensen, Sylvester Szmyd, Paolo Tiralongo, Amets Txurruka, Johan Van Summeren, Gorka Verdugo, Charles Wegelius

4 Lance Armstrong, Janez Brajkovic, Bernhard Eisel, Cadel Evans, Pierrick Fédrigo, Juan Manuel Garate, Andriy Grivko, Jesus Hernandez, Ignatas Konovalovas, Sebastian Lang, Levi Leipheimer, David Millar, Daniel Moreno, Serge Pauwels, Manuel Quinziato, Luke Roberts, Samuel Sanchez, Christian Vande Velde, Nicolas Vogondy

5 Alessandro Ballan, Matti Breschel, Alberto Contador, Cyril Gautier, Inaki Isasi, Sergei Ivanov, Vladimir Karpets, Alexandr Kolobnev, Karsten Kroon, Steve Morabito, Benjamin Noval, Jose Rojas, Nicki Sörensen, Alexander Vinokourov, Bradley Wiggins

6 Linus Gerdemann, Christian Knees, Egoi Martínez, Alessandro Petacchi, Francesco Reda, Mauro Santambrogio, Geraint Thomas

7 Jeremy Hunt, Andreas Klöden, Tony Martin, Christophe Moreau, Michael Rogers, Wesley Sulzberger

8 David De la Fuente, Ivan Gutiérrez, Danilo Hondo, Matthew Lloyd, Iban Mayoz, Dmitriy Muravyev, Rinaldo Nocentini, Daniel Oss, Kevin Seeldraeyers, Kanstantsin Siutsou, Jurgen Van Den Broeck

9 Denis Menchov

10 Carlos Barredo,Yaroslav Popovych

And here, courtesy L'Equipe, are the rankings of teams and nations:

The ranking of the least suspicious teams:
1.Cofidis 4
2. Bbox Buoygues Telecom 14
3. FDJ 15
4. AG2R-La Mondiale 16
5. Garmin-Transitions 17
6. Cervelo 20
     Footon-Servetto 20
8. Rabobank 21
9. Liquigas 22
    Team Sky 22
11. Milram 23
       Saxo Bank 23
13. Euskaltel-Euskadi 24
14. Katusha 26
15. Lampre 28
16. Quick Step 30
17. Omega Pharma-Lotto 31
18. HTC-Columbia 32
       BMC 32
       Caisse d’Epargne 32
21. Astana 39
22. RadioShack 40

The ranking of the least suspicious nations:
1. France 1.23 (based on the average of 35 riders)
2. Netherlands 1.25 (8)
3. Switzerland 1.60 (5)
4. Portugal 2.0 (3)
5. Slovenia 2.25 (4)
6. USA 2.37 (8)
7. Belgium 2.69 (13)
8. Denmark 2.80 (5)
9. Austria 3.0 (3)
10. Germany 3.27 (15)
       Australia 3.27 (11)
12. Spain 3.27 (32)
       Great Britain 3.27 (8)
14. Italy 3.70 (17)
15. Belarus 4.0 (3)
16. Russia 4.33 (6)
17. Kazakhstan 5.33 (3)
       Ukraine 5.33 (3)


Your thoughts welcome!


Kamis, 12 Mei 2011

The strange powers of placebo and a social expansion

The placebo effect, and expanding our social platform

Apologies for the long delay between posts!  With a busy work period for both of us, and a slew of bank holidays here in SA, the routine has been rather disrupted.  I'm still sitting on a series on 10,000 hours of training vs talent.  I'm also heading to the American College of Sports Medicine Annual Meeting in Denver from June 1 to June 4, and so preparing a presentation on the biological purpose and physiology of pacing strategies, which I'll share with you in due course.

But for now, a quick post to mention our new Facebook page, along with our Twitter account, where we are hoping to expand our social interaction with you.  That's part of the reason;  the other is to use Facebook and Twitter to "outsource" interesting content during these busy times.


So when Jonathan is wrapped up in Vitality work, and I'm involved in whatever happens to be the project of the moment (SA Sevens, UCT, SSISA or similar!), we'll use Twitter and Facebook to provide links to articles of interest, news stories and topics that are often what are keeping us from the site in the first place!  That way we can keep the information flowing when we don't have time for in-depth posts.

So first up, a call to get onto those platforms if you haven't already - join our Twitter feed for sports science shorts, an "article of the week" link to a paper I've been stewing over every week, as well as any other interesting stories that float across our desks.  Then join our Facebook page, launched yesterday, which replaces the old Facebook group, and will hopefully help open more dialogue and expand sports science even more.

We'll try to focus on those when work keeps us from posting more on the site!

The strange powers of the placebo effect

And then finally for today, you may recall a couple of posts in January on the Power Balance bracelets where we ended up discussing the power of the placebo effect.  Below is a great video on the placebo effect, describing some of the strange effects that have been found.  It's also really nicely put together, so enjoy!



Ross

Senin, 09 Mei 2011

Looking for a good orthodontist? My recommendation is Dr. Meat

The figure below is one of many in Weston Price’s outstanding book Nutrition and Physical Degeneration showing evidence of teeth crowding among children whose parents moved from a traditional diet of minimally processed foods to a Westernized diet.


Tooth crowding and other forms of malocclusion are widespread and on the rise in populations that have adopted Westernized diets (most of us). Some blame it on dental caries, particularly in early childhood; dental caries are also a hallmark of Westernized diets. Varrela (2007), however, in a study of Finnish skulls from the 15th and 16th centuries found evidence of dental caries, but not of malocclusion, which Varrela reported as fairly high in modern Finns.

Why does malocclusion occur at all in the context of Westernized diets? Lombardi (1982) put forth an evolutionary hypothesis:

“In modern man there is little attrition of the teeth because of a soft, processed diet; this can result in dental crowding and impaction of the third molars. It is postulated that the tooth-jaw size discrepancy apparent in modern man as dental crowding is, in primitive man, a crucial biologic adaptation imposed by the selection pressures of a demanding diet that maintains sufficient chewing surface area for long-term survival. Selection pressures for teeth large enough to withstand a rigorous diet have been relaxed only recently in advanced populations, and the slow pace of evolutionary change has not yet brought the teeth and jaws into harmonious relationship.”

So what is one to do? Apparently getting babies to eat meat is not a bad idea. They may well just chew on it for a while and spit it out. The likelihood of meat inducing dental caries is very low, as most low carbers can attest. (In fact, low carbers who eat mostly meat often see dental caries heal.)

Concerned about the baby choking on meat? At the time of this writing a Google search yielded this: No results found for “baby choked on meat”. Conversely, Google returned 219 hits for “baby choked on milk”.

What if you have a child with crowded teeth as a preteen or teen? Too late? Should you get him or her to use “cute” braces? Our daughter had crowded teeth a few years ago, as a preteen. It overlapped with the period of my transformation, which meant that she started having a lot more natural foods to eat. There were more of those around, some of which require serious chewing, and less industrialized soft foods. Those natural foods included hard-to-chew beef cuts, served multiple times a week.

We noticed improvement right away, and in a few years the crowding disappeared. Now she has the kind of smile that could land her a job as a toothpaste model:


The key seems to be to start early, in developmental years. If you are an adult with crowded teeth, malocclusion may not be solved by either tough foods or braces. With braces, you may even end up with other problems (see this).

Senin, 02 Mei 2011

Strength training plus fasting regularly, and becoming diabetic!? No, it is just compensatory adaptation at work

One common outcome of doing glycogen-depleting exercise (e.g., strength training, sprinting) in combination with intermittent fasting is an increase in growth hormone (GH) levels. See this post for a graph showing the acute effect on GH levels of glycogen-depleting exercise. This effect applies to both men and women, and is generally healthy, leading to improvements in mood and many health markers.

It is a bit like GH therapy, with GH being “administered” to you by your own body. Both glycogen-depleting exercise and intermittent fasting increase GH levels; apparently they have an additive effect when done together.

Still, a complaint that one sees a lot from people who have been doing glycogen-depleting exercise and intermittent fasting for a while is that their fasting blood glucose levels go up. This is particularly true for obese folks (after they lose body fat), as obesity tends to be associated with low GH levels, although it is not restricted to the obese. In fact, many people decide to stop what they were doing because they think that they are becoming insulin resistant and on their way to developing type 2 diabetes. And, surely enough, when they stop, their blood glucose levels go down.

Guess what? If your blood glucose levels are going up quite a bit in response to glycogen-depleting exercise and intermittent fasting, maybe you are one of the lucky folks who are very effective at increasing their GH levels. The blood glucose increase effect is temporary, although it can last months, and is indeed caused by insulin resistance. An HbA1c test should also show an increase in hemoglobin glycation.

Over time, however, you will very likely become more insulin sensitive. What is happening is compensatory adaptation, with different short-term and long-term responses. In the short term, your body is trying to become a more efficient fat-burning machine, and GH is involved in this adaptation. But in the short term, GH leads to insulin resistance, probably via actions on muscle and fat cells. This gradually improves in the long term, possibly through a concomitant increase in liver insulin sensitivity and glycogen storage capacity.

This is somewhat similar to the response to GH therapy.

The figure below is from Johannsson et al. (1997). It shows what happened in terms of glucose metabolism when a group of obese men were administered recombinant GH for 9 months. The participants were aged 48–66, and were given in daily doses the equivalent to what would be needed to bring their GH levels to approximately what they were at age 20. For glucose, 5 mmol is about 90 mg, 5.5 is about 99, and 6 is about 108. GDR is glucose disposal rate; a measure of how quickly glucose is cleared from the blood.


As you can see, insulin sensitivity initially goes down for the GH group, and fasting blood glucose goes up quite a lot. But after 9 months the GH group has better insulin sensitivity. Their GDR is the same as in the placebo group, but with lower circulating insulin. The folks in the GH group also have significantly less body fat, and have better health markers, than those who took the placebo.

There is such a thing as sudden-onset type 2-like diabetes, but it is very rare (see Michael’s blog). Usually type 2 diabetes “telegraphs” its arrival through gradually increasing fasting blood glucose and HbA1c. However, those normally come together with other things, notably a decrease in HDL cholesterol and an increase in fasting triglycerides. Folks who do glycogen-depleting exercise and intermittent fasting tend to see the opposite – an increase in HDL cholesterol and a decrease in triglycerides.

So, if you are doing things that have the potential to increase your GH levels, a standard lipid panel can help you try to figure out whether insulin resistance is benign or not, if it happens.

By the way, GH and cortisol levels are correlated, which is often why some associate responses to glycogen-depleting exercise and intermittent fasting with esoteric nonsense that has no basis in scientific research like “adrenal fatigue”. Cortisol levels are meant to go up and down, but they should not go up and stay up while you are sitting down.

Avoid chronic stress, and keep on doing glycogen-depleting exercise and intermittent fasting; there is overwhelming scientific evidence that these things are good for you.