But what about genes?

Every athlete, better said, every living organism is the result of the genes of his/her parents. It’s our genetic blueprint, or the “map” on which we can have an overview where we can go and where not, before we travel. As coaches we spend almost 90% of our time thinking about and tinkering with our programs. That is necessary, absolutely, but in my opinion it equally necessary to look at the individual you are applying this training to. One of the founders of modern medicine Dr. William Osler once stated: “It is much more important to know what sort of a patient has a disease than what sort of a disease a patient has.” Or in our language: it is more important to know what sort of athlete you want to train than to what kind of training you apply to the athlete.

Very often we still think along the line of “One size fits all”. We listen to sport scientists who try to convince us that training method A is better than training method B. In my opinion this is irrelevant, at least for elite athletes. Often we see this in weight loss diets, some people swear by a certain diet, because they lost weight, while others don’t lose weight or even gain weight with the same diet. How can that be? Well it’s simple: the diet fits the genetic blueprint of the people who benefit from it, while the same diet doesn’t work for people who have a different predisposition. Your superfood might be my poison. In training we see the same thing happen all the time: some athletes really benefit from a given program, others don’t or get injured. Again: looking at the genetic blueprint of the athletes might prevent this from happening.

I have always been interested in the genetic part of sports training but until recently, genetic testing was too expense, and not well established yet. This has now changed.

So, yes, genetic testing: what speaks against it?
I hear a lot of people speak out against genetic testing, at least for athletes.
Arguments I hear are: “Genes are irrelevant it’s gene expression that is important” . Well expressing genes is what was we already do on a daily base, we call it: training. But what if you don’t have the right genes to express or if you are the expression of the wrong genes? You can’t train a donkey the way you train a racehorse. And from a distance we can see that the donkey has a different genetic make-up from a race horse. In humans is more difficult. From the outside the difference is not as clear as with the donkey and the race horse. We cannot see whether an athlete is born to sprint, to lift, to play soccer or to run the marathon. Winners come in all sizes and types, because performance is complex and there is a lot of room for compensation. A simple example is high jump: being tall is an advantage – high center of mass. But if you aren’t you might still beat a tall high jumper by e.g. being more explosive or having a better technique. In other words, you (over-)compensate your lack of height. But here is the catch: only if you are suited to be explosive and to train and improve explosiveness. If you are short and not explosive you will have very hard time compensating these two factors by having a better technique. So the jumper who is tall, AND explosive AND has a good technique has the best change to reach the top. Of course you can increase explosiveness a lot, but not everybody to the same extent.

Another argument is: “Genetic testing is not yet fully developed, we don’t know enough yet, only maybe 1%.” My argument is simple: “than you wait until we know everything about genes and genetics which might be another 100 years, the choice is yours!” What do we know about the brain or even about the muscle? If you read enough you will see we know surprisingly little about the brain and the muscle. It does not stop us from working with it on a daily basis. I like to work with what we have even it is a little or not enough, as long as what we have is solid enough to work for my practical application.

Genetic testing will not replace other information I have about the athlete’s structures and functioning, I will just have more information.

Genetic testing will not test whether you are going to run 9.90 or 9.60 in the 100 meters. Nor will it tell you if you are going to be a top level soccer player. This last one is impossible anyway, because an excellent forward might be a lousy goal keeper, just because the functional demands, and thus the profiles, are so different.
“There are many genes that determine performance”. Absolutely true! Complex factors like speed, endurance or coordination are controlled by hundreds or maybe even thousands of genes. But could that stop us from starting to work with the ones we know? Every journey starts with the first step, and so is the solving of the genetic puzzle. Again, do you want to wait until that whole puzzle is solved? That’s good too!

As coaches we realize certainty does not exist in elite sports. We are looking at probability, increasing our chances to create successful athletes. We can deal with this uncertainty better than scientists, they only act when things are known (evidence-based). Elite performances let’s say world record levels, are an unexplored territory. Nobody has ever gone there, so nobody has the experience of being there even Usain Bolt doesn’t know what it is to run 9.30. Nobody has the experience, no evidence, so we have to do without, but we can live with that. Basically what we do is “thin slicing”, which is making an adequate judgment about a situation or a person with the least amount of information. (How big, or rather how small a slice of cake do you need to taste in order to know if the cake tastes good or bad?)

Here is another example: aspirin, who doesn’t know it? In 1898 Felix Hoffman synthesized aspirin, but only in 1971 John Vane won the Nobel Prize for unraveling the mechanism of aspirin (through prostaglandins). Between 1898 and 1971 millions of people took aspirin without having a clue about why it worked. What they knew however, was more important: it worked (and no, not for everybody, and yes, there are side effects and precautions). Lack of scientific knowledge is not always a limitation for the proper use of ideas, tools, techniques or substances.
We limit ourselves to genes we have adequate knowledge of, there is no forecasting of genetic defects leading to pathology. We have doctors for that. We stay away from pathology.

We cannot monitor training by genetic testing. Our genetic blueprint is rather static and does not change by training. What does change, however, is the gene expression, and in future this will be a valuable tool as well. Genetic testing gives where to go and where not, it can save us from wasting valuable and limited resources like time, energy and money by trial-and-error, or trying to train donkeys thinking we have race horses at hand.


  1. Sandro

    Great read,

    Excellent points and use of analogies. Also I always enjoy your mindfulness that practical application must remain in thought when considering topics.

    The truths from your post about genetics provoked thorough consideration of this topic in the context of performance as well as health. It made me question my own views and also commonly cited patient views on genetics that I commonly hear as a Consulting Specialist in Cardiopulmonary Rehab (which includes assessing “performance” at every age between birth and death and lifestyle modification).

    Many people use genetics as an excuse to give up and avoid accepting the responsibility to change their lifestyle to attain improved health. I find it interesting that research in cardiovascular disease (CVD) indicates modifiable risk factors as ninety percent (90%) of total disease risk.

    The question…

    Is the variable of genetics modifiable or is it non modifiable?
    If it is non-modifiable then this means that genetics can only account for ten percent (10%) of disease risk at best, while we are relatively sure that, gender, race, age, and socioeconomic status are the main non-modifiable risks at a given moment in time.

    However if genetics sits on the other side of risk variables (modifiable) as many researchers have suggested, this gives greater credence to the theories of gene expression and other theories about the ability to change muscle fiber type through specific training etc. The truth is we are just scratching the surface of genetics research even with new methods such as CRISPR gene editing surfacing recently. What do you think?

    The intro of the human genome project of the early 2000s was once thought to be healthcare’s savior, but we only found that a multitude of variability in genes causes varied expression that also varies with lifestyle and other environmental factors given the same mutation in two different subjects.

    Nonetheless, many people and their physicians, still believe that a diagnosis of CVD &/ or diabetes…”runs in my family” but it is obvious that this is only partially true for a small percentage of the population. The problem is that CVD accounts for approximately 50% of natural causes of death worldwide.

    CVD is a disease that most often indicates systemic inflammation that can be deadly for the most vital organs (brain and heart) but is often managed in isolation of proven causative risks such as endocrine disorders due to nutritional deficits.

    While genetics at birth can increase risk of diseases, gene expression in this context hinges on management of ones lifestyle factors, which are interestingly the same list of variables that we are interested in for performance at every level when each “risk factor” is broken down to impact on bodily systems. In healthcare we are quick to point the finger at a single body system and there are few physicians who are in the business of holistic care. Hence the rise of the Physiatrist.

    In the world of performance do you foresee the “rise” of a member of the coaching team who’s job is to consider all angles to tweak the training formula to suit the individual?

    It is highly unlikely that we can prove without reasonable doubt that an athlete has a specific genetic advantage. Therefore, in practice I agree with you that we should not wait for the researchers to release papers to guide us like sheep. We must be bold pioneers and do our own field research. When we do this we realize how enhanced focus on some isolated variables can be “fools gold”.

    If we are blind followers we limit our potential for success severely. And without a comprehensive approach we will fail even with racehorses in our stables. The training variables affecting quality performances are plentiful and coaches with the ability to manage all of these variables are few.

    1. Hello Sandro,
      Thanks for your elaborate reply. Let me try to answer in a simple way.
      1. what is non-modifiable ow could be modifiable in a few years through gene manipulation 😉
      2. many modifications take place through epigenetics, the switching on and off of certain genes
      So it would be good to know those genes, and to know if, and how they can be switched on or off.
      Some factors that we thought would be modifiable or where environmentally determined, later on
      seemed to be at least partially genetically determined e.g. repeating tendon injuries. In my opinion the distinction
      between genetic and non-genetic is rather useless. Many factors will be a combination of both, the question is to what extent
      and if modifiable: at what price of resources, time, money, effort.
      For me, DNA testing might give me some information, next to the information I have from e.g. testing and might.
      Like looking into a dark basement with a torchlight, some unexpected findings.
      Or some things I can explain now, which I could not explain before.

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