From National Geographic:

Michael Phelps stands 6 feet 4 inches (193 centimeters) and weighs 195 pounds (88.5 kilograms), with the broad shoulders and slim waist common to the elite swimmer. But consider his body measurements a little closer and it becomes clearer why Phelps is dominating these Olympic Games.

He has an extended trunk and relatively short legs, a distinct advantage in the water. The inseam of his pants is reportedly 32 inches (81 centimeters), shorter than that of Hicham El Guerrouj, the great Moroccan runner, who is 5 feet 9 inches (175 centimeters) but all legs. Phelps has double-jointed elbows, knees, and ankles, which allows him to bend himself like few swimmers can. His size-14 (European-size 48.5) feet are like giant fins. Add to that the extraordinary work rate of his lungs and heart and Phelps appears almost superhuman—a different species from the rest of us.

Of course, he also trains extraordinarily hard. But so do others. To be an Olympic champion, a person’s genes must first be preset for maximal athletic performance. After all, great athletes are born, then made better.

“The best athletes in the world are a result of good genes and optimal training,” said Phillip B. Sparling, who is a professor of applied physiology at the Georgia Institute of Technology in Atlanta. “A person who has great dedication, motivation, and excellent training will not rise to the world-class level unless he or she has inherited a supercharged physiological system for the sport.”

A refreshing change from the usual. See also this piece on Kenyan runners. More clips inside:

The speed of a sprinter is determined in large part by physiology. Muscle proteins, including key energy-producing enzymes, are dictated by genes, as is muscle-fiber composition. Great sprinters, like Maurice Greene and Marion Jones, have a high percentage of fast-twitch muscle fibers—fibers that contract quickly but tire quickly too.

A cyclist, in contrast, needs great lung capacity, for superior endurance, and strives for a high “VO2 max,” the maximum amount of oxygen the lungs can consume. Lance Armstrong, not surprisingly, has an amazingly high VO2 max.

Great cyclists generally have an extraordinary heart capacity. The average resting heart rate is 66 to 72 beats per minute (bpm). A well-trained endurance athlete has a resting heart rate of 40 bpm. Miguel Indurain, a five-time Tour de France winner and Olympic gold medalist in 1996, recorded a resting heart rate of 28 bpm. In the mountain stages of the Tour de France, Indurain could take his pulse rate up to 190 beats per minute and drop it back to 60 on the descent within half a minute.

To varying degree, these traits are all hereditary. As the renowned Swedish exercise physiologist Per-Olof Åstrand once said, “The most important thing an aspiring athlete can do is to choose the right parents.” …

The performance gap between men and women in sports is also due to genetics. Androgens—sex hormones such as testosterone—make males taller, heavier, and more muscular than females…

But genetics, particularlya person’s nerve system, also partly determines how well athletes can train and how successfully they can make adjustments and improve their technique…

All in all, a fascinating survey of human biodiversity – without any “racist” smears. It was particularly gratifying to see the mention of the nervous system, as usually the brain is exempted from consideration. But the first law of behavioral genetics says that all traits are heritable:

Such curiosities led Dr. Turkheimer to formulate with colleague I. I. Gottesman the “first law of behavioral genetics.” The law is: 1) All human behavioral traits are heritable. Dr. Turkheimer has since named two other laws. They are:

2) The effect of being raised in the same family is smaller than the effect of genes.
3) A substantial portion of the variation in complex human behavioral traits is not accounted for by the effects of genes or families.

Heritable is used in the technical sense, here. This includes motivation, conscientiousness, and work ethic. Psychometricians have measures for such variables, but I’m not very familiar with that literature (perhaps Beaujean can comment). See here, though.

Posted by godless at 01:40 PM