Today’s elite athletes are bigger, taller - study
Monday, July 20, 2009
The world’s greatest athletes aren’t just getting faster - they are also gaining in height, scientists say.
Today’s record-breaking sprinters are now six inches taller than their Edwardian counterparts, while the best swimmers have gained four inches in the last 100 years.
In contrast, the average adult has grown just two inches in height since 1900.
Scientists say height gives sportsmen such an advantage that the world’s swimming and athletics bodies may soon have to introduce boxing-style weight classes.
The ever growing size of elite athletes was highlighted last year when Usain Bolt - the 6ft 5in-tall Jamaican - became the fastest man in the world, winning gold in the 100 and 200 metres sprint at the Beijing Olympics.
Bolt is such a towering figure, he was once considered “too tall” for sprinting.
American Michael Phelps, who won eight gold medals at Beijing, is another giant. At 6ft 4in, he is four inches taller than Mark Spitz, who won seven gold medals in the 1972 Munich Olympics.
According to the Duke study, published in the Journal of Experimental Biology, Bolt is part of a trend for taller sportsmen.
[b]The researchers collected heights and weights of world record 100-metre runners and 100-metre swimmers since 1900.
They found that the swiftest runners were 6.4 inches taller than they were in 1900, while the best swimmers had gained 4.5 inches.[/b]
“In the future, the fastest athletes can be predicted to be heavier and taller,” said Dr Adrian Bejan, an engineer at Duke University, North Carolina.
"If the winners’ podium is to include athletes of all sizes, then speed competitions might have to be divided into weight categories.
“Larger athletes lift, push and punch harder than smaller athletes, and this led to the establishment of weight classes in certain sports like boxing, wrestling and weightlifting.”
The average height of adults has increased over the last 100 years because of improved diet.
Elite athletes have grown disproportionately in height because of the fiercely competitive nature of modern sport.
In Victorian and Edwardian England, athletics and swimming were amateur, part-time activities in which even a tiny sportsman had a chance to shine on the world stage.
But as sport became more professional and competitive, athletes needed every advantage - including height and build - if they were to reach the top.
Engineering student Jordan Charles, who led the study, said: “The trends revealed by our analysis suggest that speed records will continue to be dominated by heavier and taller athletes.”
[b]The researchers used their findings to develop a mathematical model that predicts an athlete’s speed based on their height and weight. Using the model, they worked out how modern-day stars would fare against the sprinters of the original Olympic Games of ancient Greece.
Charles said: “In antiquity, body weights were roughly 70 per cent less than they are today. Using our theory, a 100-metre dash that is won in 13 seconds would have taken about 14 seconds back then.”[/b]
To create their model, the scientists used two types of motion - lifting weight vertically and overcoming drag horizontally - to describe running and swimming.
Charles said his new way of looking at locomotion and size validated a technique in swim training, although for a different reason.
Swimmers are urged by their coaches to raise their body as far as they can out of the water with each stroke as a means of increasing their speed.
"It was thought the swimmer would experience less friction drag in the air than in the water. However, when the body is higher above the water, it falls faster and more forward when it hits the water.
“The larger wave that occurs is faster and propels the body forward. A larger swimmer would get a heightened effect. Right advice, wrong reason,” said Charles.
In 1930, the 100 metres dash world record was beaten by Canadian Percy Williams. Williams was just 5ft 6in tall - nearly a foot shorter than Usain Bolt.
In the 1980s, Carl Lewis and Ben Johnson won a string of records between them. Both men were 6ft 2in. 
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In the last few years, the world record has been shared by Jamaicans Asafa Powell (6ft 3in) and Bolt (6ft 5in).
(Reprinted from the Daily Mail)