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science of sport

Michael Phelps, who won eight gold medals at the Beijing Games, is described as ‘swimming in a genetic pool of his own.’Mark Humphrey/The Associated Press

Different horses are suited to different courses.

The science of athletic excellence often comes down to body type and genetics. Some people are born with a natural physiological predisposition for certain sports and can be streamed to them, says Kurt Innes, a former national cyclist who is director of talent development at the Victoria-based Canadian Sports Centre.

While it may appear all kinds of sizes and shapes have made it to the Olympic Games in London four weeks from now, they boil down to three basic body types.

Ectomorphs, typical of marathon runners, have long, thin muscles, light bones and low fat storage.

Mesomorphs, typical of track runners, have large bones, a solid torso, wide shoulders and a narrow waist.

Endomorphs, like big shot putters and weightlifters, have large, heavy bones and an increased ability to store fat.

You don't see tall, lanky gymnasts in the Olympics. Silken Laumann wanted to be a gymnast, but was born with the leverage to row, Innes says.

"We're catching up as a nation in this very specific context," says Innes, about matching body types with sports. He said an analysis of rowing showed that it's a sport of pulling and leverage, "so fundamentally you have to be quite tall with long levers [arms and legs] to maximize the performance potential.

"That's not to say a person who's not endowed with a huge arm span can't be successful, but the probability of his outperforming an athlete who is genetically endowed is lower."

American Michael Phelps, who won eight Olympic gold medals in Beijing, has the perfect swimmer's body – hands as big as dinner plates to cup water, size 14 feet (two sizes larger than typical for his size) that work like flippers, a "wing span" – a fingertip-to-fingertip arm reach – that is 6-foot-7, three inches longer than he is tall.

Phelps puts in six hours training six days a week to work on his strokes.

That's not uncommon for a high-performance athlete, but he also has mechanical advantages that can make a difference. Besides the oversized feet, hands and arm span, Phelps has the torso of a man who's 6-foot-8, the comparatively short legs of a six footer and is slim in the hips, allowing for quick turns and less drag in the water while his muscular upper body powers through the strokes. Phelps also has greater flexibility than most of his opponents in his shoulders, elbows, knees and ankles, which means more fluidity in his strokes. Phelps's own book, No Limits: The Will To Succeed, says of the ankle flexibility, "it means I can whip my feet through the water as if they were fins."

George Dvorsky, chairman of the Institute of Ethics and Emerging Technologies, described Phelps as "swimming in a genetic pool of his own." Dvorsky says Phelps's oversized feet give him a 10-per-cent advantage over competitors; he's developed, through training, greater than average lung capacity; he benefits from a genetic advantage in producing 50 per cent less lactic acid than other athletes, and therefore is less sore after workouts; and he has low body fat of only 4 per cent – half to one-third the figure cited for elite swimmers by bodyrecomposition.com.

Canadian Ben Johnson used steroids to build muscles into a thick body to pound furiously down the rubber straightaway for 100 metres. But the ideal sprinter has been getting taller over the last 40 years, Innes says. Johnson was a blip, "a stocky guy who lifted a lot of weights" and used drugs to make sure his power lasted 100 metres. The paradigm for a sprinter is actually tall, such as 6-foot-3 Asafa Powell and 6-foot-5 Usain Bolt, with long legs that, once uncoiled, cover the ground in fewer steps.

"The data jumps out, if you know what you're looking for," Innes says. "From 1968 to 2009, there were 13 significant athletes who contributed to raising the 100-metre standard, from Jim Hines of the United States to Usain Bolt of Jamaica. Jim Hines was 184 centimetres tall. Asafa Powell [who held the 100 record before teammate Bolt] was 190 … then you jump to Bolt at 196. That's a significant amount of leverage allowing this athlete to excel."

Innes acknowledges ancillary factors affecting performance, such as the strong track and field culture in Jamaica, "but from an anthropometry perspective, it's the height and leg stride that make a significant difference.

"You don't have to be much of a biomechanist to realize that you put all the other factors in the same basket and you add that six or eight centimetres of leverage, you see why Donovan Bailey [183 cm] set a world record of 9.84 seconds and Usain Bolt set one of 9.58.

"That's the kind of data sport scientists are mining and that's why you see performances going through the roof."

At the CSC, Innes matches athletes by body type and individual preference to a speed/power environment or an endurance environment. There is some basic physiological testing for assessment, such as a 30-metre sprint and an overhead medicine ball throw.

"We follow up with an in-person interview to assess the athlete's mental capacity – if they're willing to work and do the hard yards to get to the next level. From there, we try to pair them up with a sport we have access to, where there are existing clubs that have expert coaches to facilitate the next stage of the journey," he said.

For all the advantage that the right physique can give at athlete, there are exceptions, Innes says. "I jump back to the 1998 Winter Olympics in Japan, where in speed skating Hiroyasu Shimizu beat Canada's Jeremy Wotherspoon. There couldn't have been a greater contrast in size – Shimizu was 162 cm and Jeremy was 190 cm. But Shimizu won the gold because he was technically better that day. Biomechanically, he took advantage of whatever stuff he had and did it in front of a home crowd. He owned the environment and performed under pressure."

This is the seventh part in a 10-part series on the science behind athletes' preparation for the London 2012 Summer Games. Next week: Diving

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