Sharkskin swimsuits lead hi-tech bid for Olympic gold

The technological battle to win Olympic gold reached new heights yesterday with the announcement of a swimming suit designed on the hydrodynamics of a shark's skin.

The technological battle to win Olympic gold reached new heights yesterday with the announcement of a swimming suit designed on the hydrodynamics of a shark's skin.

Its inventors believe the costume will shave fractions of a second off a swimmer's performance, making all the difference between winning and losing. The swimsuit is the latest in a line of developments aimed at breaking records and winning medals by artificially enhancing an athlete's natural ability yet keeping within the letter and spirit of the Olympian tradition.

Richard Godfrey, chief physiologist at the British Olympic Medical Centre in London, said scientific enhancements to athletic kit and equipment were becoming a crucial factor in deciding who wins gold.

"Most athletes are close to the genetic limits, so there's little to choose between athletes and attention to detail becomes more important," said Dr Godfrey, who in a talk today at Oxford University as part of Science Week is to disclose how companies are overcoming technical barriers.

"Sports science and the provision of scientific services to sport are becoming increasingly important in a world where Olympic medals can be separated by hundredths of a second," he said.

Scientists are adding technological improvements to running shoes, making them springier by imparting greater "energy return"; increasingly flexible carbon-fibre vaulting poles have sent records tumbling and in archery arrows of composite materials go farther, faster and straighter.

Gold medals in Olympic swimming events have already been decided at the level of one hundredth of a second and any swimsuit that can reduce drag and even give a competitor a psychological advantage will be sought after, Dr Godfrey said.

Scientists at the Natural History Museum in London acted as paid consultants to Speedo, the British swimwear company, as part of a four-year project to make a body suit that cuts through water with the frictionless ease of nature's most fearsome marine predator.

Although only about 10 per cent of the drag caused by a swimmer is the result of friction between skin and water - the rest is down to body shape - proponents of the new suit believe the speed improvements will make all the difference between two otherwise comparable athletes, giving the wearer the equivalent of a six-metre head start in a 200m race, says Speedo. A shark's skin is covered in small teeth, or dermal denticles, arranged in sawtooth patterns to enable water to flow smoothly over the animal's outer surface.

Each denticle has tiny raised ridges, or riblets, believed to dampen turbulence in the layer of water immediately next to the skin.

Oliver Crimmen, curator of fish at the Natural History Museum, who advised Speedo, said that dermal denticles are unique to sharks and evolved to help them move easily through water - unlike other fish, sharks lack swim bladders and can only remain buoyant by constantly moving.

"Denticles make a shark incredibly smooth in one direction, paradoxically by making the skin very rough. It saves on the energetic cost of swimming. For the same energy you get more speed," Dr Crimmen said. "The teeth in the skin are holding water closer to the body and preventing the creation of eddies in the boundary layer and so reducing drag."

Speedo claims to have incorporated the hydrodynamic properties of a shark's skin teeth into the weave of the costume's fabric. It says it has gained improvements in performance over other suits, including its own previous Olympic costume, which had resin stripes to control turbulence. The company is also claiming additional enhancements of its Fastskin suit, such as three-dimensional computer mapping of a swimmer's body contours to produce a perfect fit with no fabric wrinkling, and panelled layers of the costume to mimic the action of the body's major muscle groups and reduce wobbling of the flesh.

Joe Fields, president of Speedo International, said it had registered a 7.5 per cent reduction in glide time - the moment a swimmer pushed off after a turn - leading to an overall improvement of 3 per cent when the suit was worn on world-class competitors. "Independent testing shows this to be the fastest suit ever made. Some of our team swimmers have shown time savings enough to make a difference between winning and losing a race," Mr Fields said.

Borrowing ideas from nature - bioprospecting - is not new to the industry, although it is a novel approach for athletic-equipment companies. "It's grabbing good ideas from nature. The answers are often found in nature first. Some people may look upon this as cheating," Dr Crimmen said.

However, although Speedo claims to have stolen a march on rival companies, British swimmers at the Olympics in Sydney this summer are unlikely to reap the benefits. The official sponsor for the swimming team is Adidas, which insists competitors wear its own, non-sharkskin suit.

Speedo says leading United States and Australian swimmers have signed up to wear its costume in Sydney.