Hint: Choose your parents wisely!
Being an Olympic year, and with the 2008 Summer Olympic Games in Beijing, China, now upon us, it is only right that we discuss how exactly to become a great and even legendary athlete. After all, predicting athletic performance is a bit of the "holy grail" in sports science, and around big competitions such as the Olympics this is always a hot topic. And since we had a convergence of events here at the Science of Sport with the birth of Jacques Dugas, the Tour de France, and the Beijing Olympic Games all within a few weeks of one another, this is a fantastic opportunity to take a tongue-in-cheek look at athletic performance and how we can predict it!
Why predict performance?
As mentioned, this is a kind of "holy grail" area in Sports Science, and plenty of scientists have devoted much time and effort to this topic. The not-so-obvious reason to engage in this line of research is simply for the pursuit of knowledge, and also because if we could unlock the mechanisms that predict athletic performance, those findings would likely lead to many other "secrets" of human physiology and greatly enhance our understanding of the human body.
The more obvious reason is for talent identification. Owners, coaches, managers, and scouts, often live and die by their ability to identify the next David Beckham, Haile Gebrselassie or LeBron James. Plenty (ok, a lot!) of time, money, and effort are invested in locating the next great athlete in any given sport, signing that player to a multi-year contract, and then developing that great talent into the next legend. Of course the financial benefits for all parties can be staggering if they get it right, and hence the great emphasis on the talent identification process.
Red herrings from the past
For many years one's VO2max was thought to be the best predictor of endurance performance. Since endurance exercise relies on producing energy from oxidative means, it seemed only a short leap to equating superior VO2max with superior endurance performance. The funny thing is that many coaches and scientists alike still believe this to be true. However, and we have written about this here before, if we were to measure the entire peloton in this year's Tour de France, and plotted them against their overall placing, we would see little or no relationship. The same holds true if we were to plot their individual performances in just the 53 km time trial. The problem here is the physiologically the cyclists in the peloton are very similar to each other. To ride at that level one probably needs a VO2max of at least 65 mL/kg/min, but we will also find plenty of good recreational cyclists with VO2max measurements of 65 or even higher (in fact mine is 71 mL/kg/min, but I am no where near close to quitting my day job to pursue life as a pro cyclist!)
One important aspect to consider and understand here is that to be a "good" endurance athlete, one must have a relatively high VO2max, say for example about 60 mL/kg/min. If you are already endurance trained and your VO2max is below 50, you are unlikely to set any endurance records and probably will not run a sub-three marathon.
So VO2max is a descriptor in the sense that it helps us describe a given population of athletes, but it will not predict who will be the best athlete, and that is because your VO2max is not the cause of your performance. . .rather, your performance is the cause of your VO2max. Let's call it a prerequisite as opposed to a predictor. By this we mean that some other factors are ultimately responsible for the fact that you cane everyone in your running club at the weekly time trial, and because you have these other characteristics, your brain allows you to activate more muscle, which leads to faster running speeds, and because you use more muscle you have a higher VO2max (since muscle is the metabolically active tissue). To understand this better, please see our series on fatigue for a much more in depth discussion and explanation about these concepts.
The "ACE" gene and athletic performance
One of the first genes to be associated with athletic performance was the "ACE" gene. "ACE" in this context does not refer to a superior baseball pitcher, though, but rather the "Angio-tensin converting enzyme." It is an enzyme involved in fluid balance and has an association with performance. In other words, some people who have specific variations of this gene do better in endurance events or respond better to endurance training. Many have studied this gene, and the pdf file for one of those studies can be found here.
There does seem to be some association between some aspects of performance and this gene, but it is far from being a single predictor of athletic performance. The study above from Nature could show only that the subjects with the one genotype responded better to endurance training, but did not really measure performance outright. And although one's ability to respond to training is vital to performance, it will not guarantee success and accounts for only some of what we see. In addition to responsiveness to training there are still many other characteristics you must possess, for example superior visual acuity and superior neuro-muscular control just to name two.
Understanding performance: Choose wisely!
Perhaps we need to approach sporting performance from a slightly different angle. A great quote by Professor Tim Noakes goes like this:
"Sports is a Darwinian selection process that selects out the group of people who are genetically predisposed to be successful in that sport. If you don't have the genes, you aren't going to make it."Hence the title of this post: "Choose your parents wisely!" While we will be the first to admit that a myriad of factors and variables must converge to produce superior athletic performance, it is perhaps the genetic component that plays the biggest role. This can be illustrated by some rather simple examples.
Generally speaking the best endurance runners are rather small individuals. If they are not shorter than six feet, then they are "ectomorphic," or tall and lanky. The reason for this has to do with the energy demands of moving your body, which is your metabolic rate or essentially your mass multiplied by your velocity. Simple math will tell you that when running at 4:00 per km (about 6:25 per mile) it will cost a 100 kg individual much more than it will cost a 60 kg individual. In fact, the 100 kg person might be working at 100% or more of their max, while the 60 kg person will be exercising at a much lower intensity. And no matter how hard the 100 kg athlete trains and works, he will never weigh 60 kg, and in fact he will never weigh much less than 90 kg probably---his genes dictate that he has a relatively massive physique.
We can also examine this going the other way. To play any position in the NFL, even the smallest, more or less requires a minimum mass of perhaps 85 kg (187 lbs). That just seems to be what the sport requires, more or less. And again, no matter how hard I train and no matter how many weights I lift, no matter how much "bulk builder" shakes I drink, I will likely never weigh much more than 80 kg. . .or I will, but I will not be 12% body fat! So here genetics also tells me that I am highly unlikely to be successful at the power sports.
The process of self-selection
The individuals who possess all the right genes (genotype) and are provided with the correct environment (phenotype) will then excel in a given activity. By self-selection we mean that an individual will be drawn to an activity in which he or she excels, and will cease participating in those activities in which they perform poorly. The exception to this rule occurs in those sports whose cultures require intense and consuming participation from very early childhood, sports such as gymnastics and diving. In those cases, the kids hardly have a chance to select themselves into a different sport in which they might be more successful as the adults who surround them make the selection at a very early point in time.
Infrequently we see the convergence of all the necessary traits for superior sporting performance. It does not happen often, but those in the past and present include Connie Carpenter-Phinney, a successful and Olympic level speed skater who turned to cycling after an ankle injury and went on to win Gold in the Los Angeles Road Race in 1984, among many other victories. Two other modern-day examples are Bo Jackson and Deion Sanders. Both excelled in the NFL and MLB, and although neither posted legendary numbers, they turned in respected performances in both sports. In fact Sanders completed on both the World Series and the Superbowl. Further, the fact that teams were willing to sign them (for lucrative contracts) says much about the value placed on them as athletes.
But this being an Olympic year and an Olympic post, let's not forget Sheila Taormina. In 1996 she won gold in Atlanta on the 4 x 200 m freestyle relay team. Four years later she finished sixth in the triathlon in Sydney, and in 2004 she won the triathlon world champs. She again competed at the Olympic level, but finished only 23rd in Athens. Which brings us to 2008 and yet another summer games with Taormina, this time in the modern pentathlon! Clearly she has the genes, as evidenced by her transition from swimming to triathlon. When we think of what predicts performance in swimming, we do not associate those characteristics with running or cycling performance, yet she was competitive on both sports.
Genes + Environment = Success
So we must realize that to succeed at the highest levels of sport one must clearly have the genes. However at the same time you must be exposed to the appropriate environmental stimuli that will permit you to exploit your superior genes. We guarantee that for every Bo, Deion, and Sheila, there are countless others who do in fact possess the genes for superior athletic performance, but instead of training six days a week, they are are working a desk job six days a week---and that is simply because they were not exposed to the "right" environment for them to end up as an athlete.
So you can now watch with an added layer of understanding as your athletic heroes triumph in their event. They trained hard to get there, to be sure, but they have their parents to thank in more ways than one!