Thaindian News

Washington, July 18 (ANI): The 2008 Olympic Games in Beijing saw that winning athletes are getting bigger in size than they used to be in the past decades, and now a theory by Duke University engineers has explained the reason behind this evolutionary trend.

The theory, called that constructal theory, has shown that not only have Olympic swimmers and sprinters gotten bigger and faster over the past 100 years, but they have grown at a much faster rate than the normal population.

The constructal theory is a Duke-inspired theory of design in nature that explains such diverse phenomena as river basin formation and the capillary structure of tree branches and roots.

In a new analysis, Jordan Charles at Dukes collected the heights and weights of the fastest swimmers (100 meters) and sprinters (100 meters) for world record winners since 1900.

He then correlated the size growth of these athletes with their winning times.

“The trends revealed by our analysis suggest that speed records will continue to be dominated by heavier and taller athletes,” said Charles, who worked with senior author Adrian Bejan, engineering professor who came up with the constructal theory 13 years ago.

Charled added: “We believe that this is due to the constructal rules of animal locomotion and not the contemporary increase in the average size of humans.”

While the average human has gained about 1.9 inches in height since 1900, the new research has showed that the fastest swimmers have grown 4.5 inches and the swiftest runners have grown 6.4 inches.

The theoretical rules of animal locomotion generally state that larger animals should move faster than smaller animals.

In the constructal theory, Bejan linked all three forms of animal locomotion — running, swimming and flying.

Bejan has argued that the three forms of locomotion involve two basic forces- lifting weight vertically and overcoming drag horizontally.

Thus, they can be described by the same mathematical formulas.

Charles said that this new way of looking at locomotion and size validates a particular practice in swim training, though for a different reason.

Usually coaches urge swimmers 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 that 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. The results of the analysis were published online in the Journal of Experimental Biology. (ANI)