genetics and sports performance

Genetics And Performance: What research tells us about African runners: are they really genetically more gifted?

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African runners are genetically superior to white runners. Compared to whites, blacks are better suited for sports which involve short, explosive bursts of energy. Individuals from West Africa 'make' good sprinters, while people from East Africa are endurance types..

Those are strong statements. Many people believe them. And implicit in the statements are two inferences that usually remain unstated: (1) If blacks are physically exceptional, then they don't have to go through the mental turmoil of constructing a rigorous training programme; they can just let their bodies work their magic. (2) Whites are at a disadvantage. Since they're handicapped by bad genes, and therefore by their anatomy and physiology, they will never be able to compete equally with Africans..

Of course, believers in black 'super-genes' haven't been able to explain exactly how Africans have managed to corner the market on superior genetic material. When the Finns dominated the running world in the 1920s and again in the 1970s, no loud voices proclaimed that Finnish runners were genetically superior. Instead we pondered the merits of reindeer milk and called Lasse Viren a potential blood doper. When the Brits dominated middle-distance running in the 1950s and 1980s, there was no talk about brilliant British genetic material. Rather, we heard about British pluck and hard work. And when the Chinese women ran wild in 1993, it was because they were drugged, not because red-hot genetic material had fired up their performances. But now that Africans are running wild, the genetics lessons begin. Somehow, Providence has chosen to bless only African runners with top-quality DNA..

Opinions, not facts
It's time for a reality check. Although beliefs about genetic differences between African and non-African runners are widely held, it's important to remember that these beliefs are opinions - and nothing more. There's simply no scientific evidence to support the idea that African runners are genetically superior to European, North American, Asian, or South American athletes..

Why isn't there any evidence? At present, we don't even know WHICH genes are necessary for topflight performances! Since we don't know which genes are important, it's impossible to measure the relative frequencies of performance-enhancing genes in different groups of athletes. In addition, as explained at the end of this article, the available scientific research suggests that genetic factors are less important than non-genetic factors (including training and lifestyle) in determining performances..

Still, when Mr. Gebrselassie of Ethiopia rips through the 5K in a world-record 12:44 or Mr. Kiptanui from Kenya slashes the 3000-metre steeplechase mark, the familiar refrain begins again: Africans have the most slender upper bodies, the thinnest bones, the most rail-thin calves, the most tent-like lungs and the most reservoir-like, elephantine hearts - all because they have the optimal genetic make-ups. As a result, we don't need to concern ourselves too much with how the Africans train, or how they think about running, or what motivates them to run far ahead of everyone else. It's enough to believe that they were born with a vast talent which places them head and shoulders above the pack..

Why? Now ask them how?
Continuing to rely on the 'genetic explanation' for African superiority has negative consequences. After Africans win the vast majority of distance medals at the Atlanta Olympics - as they inevitably will - and then return to their continent, anyone saying that they won their hardware because of their genes is giving a huge insult to their untiring work and relentless motivation. And summoning up the hocus-pocus of genetic differences makes the running community less eager to actually learn something useful from the top African runners. You've probably noticed that people aren't exactly beating down the Africans' doors in order to understand how to train, even though the Africans have blown the socks off runners from the rest of the world. Instead, we continue to 'learn' from the same old coaches and gurus who have worked with and trained runners considerably slower than the current crop of Africans..

That's a bit strange. In the business world, we ask the top executives how they've managed to make their companies so successful. In the medical field, we ask the very best surgeons specific questions about their surgical techniques. But do we ask the Africans for training information? Why is it so much more convenient to believe that Africans have risen to the top because of inborn talent?

What the research actually says
There are just three relevant studies in the scientific literature that have examined physiological differences between Africans and non-Africans, and none of the three actually looked specifically at gene quality. That's no surprise; since, as mentioned, scientists don't actually know which genes code for endurance performance, they can't possibly determine whether Africans have a lockhold on superior genetic material. We don't know what 'superior genetic material' actually is..

So, instead of looking at actual genetic differences, scientists have made inferences about genes based on the physiological differences which they detect between blacks and whites. In a study carried out by Claude Bouchard and his group at Laval University in Quebec, 23 black male students and 23 Caucasian male students were compared. The black students hailed from Cameroon, Senegal, Zaire, the Ivory Coast and Burundi (mainly, that is, from the western and central parts of Africa), while the Caucasians were born in Canada and were of French descent. Both the Africans and Caucasians had an average age of 25, weighed about 154 pounds and were about 5'9' tall. All the students were sedentary at the time of the study..

No gene frequencies were measured, but Bouchard found that both groups had the same percentage (about 18 percent) of type IIb muscle fibres - the cells which are critically important for sprinting (so much for the idea that western Africans have muscles uniquely suited for high-speed running!). There were two key differences in muscle composition between whites and blacks: Caucasians had a higher percentage of type I cells (41 vs. 33 percent), while Africans checked in with more type IIa muscles (49 vs. 42 percent). As you know, type I fibres are great for prolonged, moderate-speed endurance performance, as in an event like the marathon, while IIa cells promote faster running times in shorter events like the 5K..

Although Africans had more IIa cells and fewer type I cells, we can't say that these differences are genetically based. For one thing, studies show that muscle fibre type is not tightly regulated by genes. Also, an individual's muscle-fibre composition can change over time. IIb fibres can probably become IIa cells, and IIa cells may be able to become type I fibres. Thus, it's impossible to say that the blacks' higher frequency of IIa fibres was a genetic thing..

The only other key difference between the Africans and Canadians was that blacks had higher concentrations of 'anaerobic' muscle enzymes, which are chemicals that spur the production of energy during short, intense running, whereas whites showed up with greater levels of 'aerobic' enzymes needed for continuous, endurance exercise. Again, there's no reason to conclude that these physiological differences are caused by genetic differences. The increased anaerobic-enzyme density in blacks might have simply been the result of their higher frequency of IIa cells..

The Laval scientists concluded that 'black individuals are, in terms of skeletal muscle characteristics, well endowed for sport events of short duration'. That's a somewhat shaky conclusion, since blacks and whites had exactly the same concentrations of IIb cells, the ones which are critical for sprinting, although it was true that blacks had higher amounts of anaerobic enzymes. As mentioned, it was impossible to say why the blacks' muscles were more tilted toward IIa fibres and away from type I cells. It might have been genetics, but it might have been the result of lifestyle, too..

What Tim Noakes found..
In a separate study carried out several years ago, Tim Noakes and his colleagues at the University of Capetown compared elite black vs. elite white South-African runners. Although both groups had similar 5-K times (about 13:45), the blacks were considerably faster in 10-K and half-marathon races. VO2max, running economy, maximal running velocity, training mileage and the percentage of type I muscle cells were exactly the same in the two groups, but there were some differences: (1) blacks ate more calories and carbohydrate per pound of body weight, compared to whites, (2) blacks trained considerably faster than whites, (3) blacks produced less lactate while running at race speeds, and (4) blacks were quite a bit shorter than whites (5'6' vs. 5'11') and weighed less (123 vs. 154 pounds)..

Note that only point four can be firmly pinned to genetics. Body height - although influenced by the environment - is fairly strongly determined by genes, and body weight tends to follow from height. Eating more calories and carbohydrate (point 1) is a lifestyle factor. Running at higher training speeds (point 2) often is part of an overall training philosophy that emphasises intensity rather than volume and is not necessarily coupled with a particular genetic constitution. Producing less lactate while running at high velocities (point 3) might simply be a long-term result of the more intense training carried out by blacks. Overall, Noakes' work provided no solid evidence that blacks were genetically different from whites.

Continued »

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