Soccer articals

You may have noticed that the Greeks and Serbian researchers were not consistent in their findings relating to body type propensities and basketball playing position. The Greek guards for example had greater mesomorphy (and endomorphic tendencies) than their Serbian counterparts; however, it was the Serbian centres who were more mesomorphic with endomorphic tendencies.

This throws up a very interesting conundrum and challenges the assumption that only certain classifications of body types are suitable for certain sports/positions. Although it is a given that being tall will be a distinct advantage for basketball, it may well also be that training factors or even the natural genetic tendencies of a race can also influence the ‘ideal playing position shape’. This also chimes in with recent research identifying the presence of certain ‘sporting genes’ – ie genes that are a positive asset for sports performance (more on this later).

Nature versus nurture and the identification of sporting genes

Body type is established at birth, while body shape is the result of physiological adaptations to training, diet and lifestyle factors. However, there are sufficient anomalies in sport to show that body types can vary (to a degree) within a sport and player positions. Compare for example the more endomorphic-mesomorph body shape of English striker Wayne Rooney with the more ectomorphic-mesomorph French striker Thierry Henri – both great footballers.

According to Mike Rennie, professor of clinical physiology at the University of Nottingham Medical School in Derby, the split between nature and nurture is about 55:45. He provides the example of identical twins from Germany, one of whom was an endurance athlete, the other a power sportsman(4).

Nurture is of course a powerful influencing factor and one that is often cited in the case of Kenyan distance runners who have won more distance, steeplechase and cross-country Olympic and world titles than any other nationality. However, the famed running doctor Tim Noakes indicates that these runners have a greater preponderance of fast-twitch muscle fibre, especially when compared to their North American and European counterparts(5).

But it is also possible to argue that this is a training response and not a genetic one as most humans start off with a fairly even distribution of fast- and slow-twitch muscle fibres. And perhaps even more crucially for the nurture argument, running is an endemic feature of Kenyan life. It’s also one of the few areas where Kenyans can display their prominence on the world stage and gain individual notoriety and wealth; this makes it all the more likely for them to do it.

Jargonbuster

Fast-twitch muscle fibre

Power and speed producing muscle fibre

Slow-twitch muscle fibre

Endurance producing muscle fibre

Sporting genes

Research has recently begun to appear on sporting genes. These are specific identifiable genes that have been found to be relevant to enhanced sports performance. By 2005 nearly 200 genes had already been identified as having a direct effect on sports and fitness performance and training adaptation(6).

The EPOR (erythropoietin receptor) gene, for example, has been identified as crucial for red blood cell production. In some people this gene mutates and continues to work producing an abnormal amount of red blood cells. Finnish researchers identified an entire family with this EPOR mutation, several of whom were championship endurance athletes, including the great cross-country gold medalist skier, Eero Mantyranta(4). Mantyranta won two gold medals at the 1964 winter games and it was discovered that EPOR mutation allowed him to produce 50% more red blood cells(7).

As red blood cells are crucial for carrying oxygen to the working muscle the EPOR gene is crucial for enhancing aerobic performance, regardless of body type. Other similar genetic research has indicated that one in five Europeans cannot produce the alpha-actinin-3 protein found in fast-twitch muscle fibres. This genotype is crucial for speed and power sports(4). A lack of it appears to reduce the potential for Europeans to be as fast as their Afro-American counterparts. Coincidentally it is being argued that the first genetically mutated athletes could be competing in next year’s Olympic games!

Body shape is the trained response or the everyday life response/effect that ‘changes’ an individual’s body type. Long distance runners may have a body type that has mesomorphic tendencies; however, while they are in training, due to their high calorie expenditure and lack of training emphasis on building (and maintaining muscle) they may well develop a more ectomorphic shape. At the other end of the spectrum, countless millions of the sedentary general public will gradually take on more of an endomorphic shape as they gain weight, due to a lack of exercise, excess calorie intake and poor food choices generally!

Body type analyses provide a strong starting point for sports selection, prowess and training response. Although it is very much the case that certain body types seem better suited to certain sports, there is still very much a degree of ‘you are what you train for’. This is true within certain parameters and has been exemplified by research pointing to differences and anomalies within playing position in basketball (and other sports). Additionally, the more recent research into sporting genes could have even greater implications than body type in terms of ‘determining’ who will be good at certain sports and indeed who will be ‘made’ better at sport.

John Shepherd MA is a specialist health, sport and fitness writer and a former international long jumper

References

Sports Med Phys Fitness 2006 Jun; 46(2):271-80

J Sports Sci 2005 Oct; 23(10):1057-63

J Strength Cond Res 2006 Nov; 20(4):740-4

The Guardian, Thursday August 5, 2004

The Lore of Running, Noakes T

www.medscape.com/viewarticle/551096

www.newscientist.com/channel/life/ genetics/mg19125655.300-only-drugs-can-stop-the-sports-cheats.html

That is a question that has obsessed many commentators in the sports science community for a number of years – and the answer is less clear-cut than it used to be. The authors of a leading article published in the prestigious British Journal of Sports Medicine point out that: ‘Although serious consideration does not indicate the slightest chance of a woman being the fastest human on the planet at distances of 100-200m, there are factors that may favour women over longer distances’.

It is not only the rapid improvement in female running, especially over the marathon distance, between 1963 and 1984 that supports this idea, they explain. Further backing comes from scientific evidence of natural female advantages, including the ability to run aerobically at a higher percentage of maximal oxygen uptake, resistance to oxidative stress and a higher pain threshold.

And, although men show no signs as yet of being beaten over Olympic distances, they are already beginning to lose the battle at ultra-distances. As the leader points out, consistent male superiority is already a matter of history in possibly the most challenging ultra-race, the ‘Badwater Ultramarathon’, a 216k race at crucifying temperatures of up to 55°C. Although men dominated this race during the 1980s and 1990s, in 2002 and 2003 a female ultra-runner outpaced the fastest man by about 4.5 and 0.5 hours respectively. Furthermore, since 2002 up to three women have been in the first five finishers, even through there were more male than female participants.

Pundits will be watching with intense interest to see whether this apparent advantage can be transferred to shorter races.

Br J Sports Med 2005; 39:410

gender performance

Gender Performance : Will women ever outpace men?

Will females ever outpace males in running events? Time and again this question has led to fierce debate within the lay and scientific community ^(1-6). Performance differentials between men and women are most commonly attributed to such issues as body size and composition, with men tending to be larger than women, with a lower percentage of body fat combined with a higher relative muscle mass. From this perspective, there is not the slightest chance of a female being the fastest human on the planet over 100m or 200m, argue Professor Ralph Beneke and Dr Renate Leithäuser.

Men also have a higher aerobic capacity and a bigger absolute and relative mass of haemoglobin than women. But, while these attributes appear to give men an advantage in endurance events, their greater muscle mass can be a disadvantage in such events.

Rapid improvements in female marathon performance between 1963 and 1984 (see figure 1, below) served to support the idea that women might one day outpace men in long-distance events ⁽⁴⁾. However, marathon performances by both sexes are more likely to reflect historical than biological factors.

Figure 1: graph showing reductions in male and female world-best marathon times from 1908, with projections to 2050. Note that the model implies women will never outpace men in the marathon

Male marathoners demonstrated huge improvements during the early years of the last century, after the current marathon distance was established as an Olympic event. After near- stagnant progress between the 1920s and 50s, a new period of rapid improvement was ushered in by scientific progress in coaching and sports medicine, although the rate of improvement slowed down significantly after the 1970s.

The lack of improvement in female marathon performance between 1926 and 1963 can be attributed to the fact that women could not officially participate in marathon races. In fact, in spite of dramatic improvements in female performance during the 1970s, 80s and 90s, it wasn’t until 1984 that the marathon became a female Olympic event.

However, men have always been faster than women over every Olympic distance, and a model applied on all world best results over the marathon distance set since 1908 predicts an endpoint of marathon performance in females at two hours, 15 minutes (see figure 1). This prediction may be a rather conservative if not pessimistic view, particularly in the light of the fact that this time was almost reached (by the UK’s Paula Radcliffe) in 2003. However, when applied to males, the model forecasts faster times than previously predicted (1:57:46). Irrespective of whether such a model allows for meaningful extrapolations to the near or far future, it clearly supports the idea of a near- plateau in gender differences at this distance ^(6,7). Further analyses supported the idea of a steady gender difference of about 10% in races up to 200km ⁽⁸⁾. Nevertheless, there are some important factors that may favour women over very long distances.

Any form of exercise starts a series of acute physiological reactions involving activation of the hormonal and autonomic nervous system. These responses affect, in turn, the conversion of food to energy and the subjective perception of exercise ⁽⁹⁾. And there is evidence that these effects are highly gender-specific ⁽¹⁰⁾.

There is some evidence that women can run aerobically at a higher percentage of their maximal oxygen uptake than men ⁽⁷⁾. During the early phase of a 90-minute run, women were able to convert more fat to energy than men; and, more importantly, if a carbohydrate drink was provided during the run, they were able to convert a greater relative proportion of it to energy than men.

The implication of this research is that carbohydrate ingestion, which is particularly common in longer events, is likely to be more effective in conserving the body’s own glycogen stores in women than in men, which would be particularly conducive to success in races longer than the marathon.

Other research has shown that women are more resistant than men to the potentially damaging oxidative stress that accompanies endurance exercise ⁽¹¹⁾. This is partly because they have more effective mechanisms for breaking down fats into their constituent fatty acids – a process known as ‘lipolysis’ which acts as a defence against oxidative stress ⁽¹²⁾.

Whether or not such findings provide meaningful clues to whether or not women will be able to close the performance gap in races up to 200k, consistent male superiority is already a matter of history in possibly the most challenging ultra-race, the Badwater Ultramarathon. This event, starting in California’s notoriously inhospitable Death Valley, is a 216k one-stage race performed at temperatures up to 55°C and bedevilled by challenging uphill and downhill stretches, as illustrated in figure 2 below.

Males dominated this event during the 1980s and 90s. However, despite the fact that women have less effective mechanisms than men for regulating their body heat in extremely hot environments ⁽¹⁴⁾, in both 2002 and 2003 a female ultra-runner outpaced the fastest male by about 4.5 and 0.5 hours, respectively. Furthermore, in each of the last three years, up to three women have been within the first five finishers – particularly impressive given that this is a race that has always attracted significantly more male than female participants.

Will females consistently outpace males over such ultra distances in the future? That may soon be a matter of fact rather than conjecture.

Professor Ralph Beneke (BSc, MD, PhD) and Dr Renate Leithäuser (MD, PhD) are both physicians and sports and exercise scientists at the University of Essex. They are both involved in the training of world class athletes

References

1. 
   Br J Sports Med 39(7):410
   
2. 
   Nature 431:525, 2004
   
3. 
   Science 305:639-640, 2004
   
4. 
   J Appl Physiol 67:453-465, 1989
   
5. 
   Nature 355:25, 1992
   
6. 
   J Sports Med Phys Fitness 44(1):8-14, 2004
   
7. 
   Int J Sport Nutr Exerc Metab 13(4):407-421, 2003
   
8. 
   Can J Appl Physiol 29:139-145, 2004
   
9. 
   J Endocrinol Invest 26(9):879-85, 2003
   
10. 
    Pain 96(3):335-342, 2002
    
11. 
    Arch Med Res 35(4):294-300, 2004
    
12. 
    Eur J Appl Physiol 85:151-156, 2001
    
13. 
    J Endocrinol Invest 27(2):121-129, 2004
    
14. 
    Sports Med 229(5):329-359, 2000
    
15. 
    Sports Science Glossary Part 6
    
16. 
    Sports Science Glossary Part 6
    

The record for an event, plotted against time, falls roughly along a straight line

The record for an event falls along a curve that flattens out gradually with time

The ability to process oxygen for conversion to energy

A substance contained in red blood cells that is responsible for transporting oxygen around the body

Governs bodily functions that are not under conscious control – eg heartbeat

A series of reactions to increased use of oxygen, including the production of potentially harmful ‘free radicals’

A hormone that promotes growth of the long bones in the limbs and increases protein production by the body

Researchers have long speculated on the factors that contribute to making an elite athlete. When a particular group appears to dominate a given domain, even more speculation and interest is generated. Current examples from sport include the American dominance of basketball and the Northern European dominance of Nordic skiing. An example that has garnered much attention^(1,2) is East African dominance of middle- and long-distance running. Although several empirically based positions have been advanced to explain the interindividual variation in performance^(3,4), the dominance of black athletes in certain sports has been commonly attributed to factors such as social Darwinism – that is, the hardships of slavery resulted in a degree of genetic selection⁽⁵⁾ – and environmental determinism – that is, physiological adaptations associated with living under certain environmental conditions ⁽¹⁾.

Hamilton ⁽⁶⁾ examined empirical evidence for a range of influences that may contribute to East African running dominance, including environmental, social, psychological, and physiological variables. After examining research from various disciplines, he concluded that there was no clear explanation for the East African supremacy. However, Hamilton argued that psychological factors may perpetuate this dominance by attributing differences between African and white running performances to stable external factors, thereby disempowering white runners and empowering East African runners. Regardless of the possible existence of physiological advantages in East African runners, belief that such differences exist creates a psychological atmosphere that can have significant consequences on performance.

Stereotype threat

Recent research in psychology has unveiled insights that are particularly relevant to this debate. It is distinctly possible that what we believe to be true about our genetic make-up may be more important than what is actually true.

Stone et al⁽⁷⁾ gave black and white students a laboratory golf task that ostensibly measured ‘natural athletic ability’, ‘sport intelligence’, or ‘sport psychology’, depending on how the test was presented. Nothing changed in the test itself, just the perception of what the test measured. Both black and white students scored equally well on the sport psychology control condition. However, black participants outperformed white ones when the task was framed as a test of natural athletic ability, whereas white participants outperformed black ones when the task was framed as a test of sport intelligence. This phenomenon is referred to as stereotype threat and may be of help in explaining the dominance of certain sports by specific groups. Although scientific inquiry into genetic differences between races remains unresolved, previous research suggests that belief in such differences has a large impact on performance.

Steele and Aronson⁽⁸⁾ introduced stereotype threat as an explanation for the lower scores of black American students on standardised intelligence tests. The authors had been perplexed by the persistent gap in scores between blacks and whites, which endured even if black students came from well educated families of middle-class standing. However, Steele and Aronson found that black students scored just as well as whites on standard intelligence tests when the tests were presented as diagnostic tools that did not measure intellectual capacities. They determined that it was not the test itself, rather the situational pressure surrounding the test, that resulted in poorer scores. Performance decreased when black students were confronted with the possibility of confirming a widespread stereotype about low intelligence in blacks.

Significantly, stereotype threat affects the academic vanguard more than it does the weaker students. A person has to care about a domain in order to be disturbed by the prospect of being stereotyped in it. Good students are generally invested in and have identified with the domain and thus are more prone to the situational pressure that is stereotype threat. Students who did not identify with the domain were remarkably unaffected. Weaker students reduced cognitive effort as soon as the test became challenging, resulting in poor performance, regardless of whether they were under stereotype threat or not⁽⁹⁾. Therein lies another key to stereotype threat – the test must be challenging. It is only when one gets to a difficult section, and the possibility arises of confirming the negative stereotype, that sufficient stress arises to impair performance.

Oddly enough, a person does not even have to believe the stereotype to be affected by it. Awareness, even at a subconscious level, appears to be sufficient. For example, Levy ⁽¹⁰⁾ primed [senior citizens] using subliminal messages and then gave them a memory test. Those who had been primed with negative words associated with old age, such as senile or forgetful, performed worse than seniors primed with positive words like wise and sage.

Spencer et al ⁽¹¹⁾ found that stereotype threat was equally applicable to women and maths skills. If women are reminded of the stereotype that they are inferior to men in mathematical ability, their test scores decrease. If the same test is reframed so that women believe it is simply a research tool, they score just as well as men. Current findings indicate that anywhere a stereotype exists, stereotype threat can be invoked and performance depressed. In a related study, white men, selected on the basis of their strong maths skills, performed worse when they were compared with Asian men, a group traditionally thought to excel at maths. A control group not subjected to stereotype threat suffered no such performance decrease ⁽¹²⁾.

The sporting field also contains its share of stereotypes, particularly when it comes to black-white differences. The perception of the athletic superiority of black people is widespread, with the media contributing substantially to such thinking ^(2,5). Stone et al⁽¹³⁾ examined popular perceptions of racial stereotypes by having participants evaluate the abilities of a male basketball player based on a radio broadcast of a college game. Even though participants listened to the same broadcast, they were more likely to attribute talent and natural athletic ability to the player if they thought he was black and were more likely to attribute hard work and sport intelligence to the player if they believed he was white.

This widespread societal belief in the athletic superiority of blacks is actually a relatively recent phenomenon. Hoberman ⁽¹⁴⁾ notes that during colonial rule blacks were considered inferior sportsmen. In fact, at the dawn of the 20th century there was concern even among black scholars at the lack of physicality of the black race⁽¹⁴⁾. However, the tables have turned considerably in the past hundred years. Impressive accomplishments from black athletes during the first decade of the 1900s – for example, Marshall Taylor and Jack Johnson – followed by the record-breaking performances of black sprinters like Jesse Owens provided the basis for the belief that black athletic superiority is genetic in origin⁽¹⁵⁾. The current dominance of black athletes in a number of high-profile sports has certainly done nothing to dispel this belief. Furthermore, as Hamilton suggests⁽⁶⁾, the psychological edge this belief gives black athletes may be the key to maintaining that superiority. Indeed, in stereotype threat we see evidence of the power of such beliefs.