for National Geographic News
At the Summer Olympics, which begin in Athens, Greece, next week, the world's elite athletes will once again dazzle us with their almost superhuman qualities. At times, they will seem like an entirely different animal from us mere mortals.
But though they push their bodies to the absolute limit, elite athletes are far from invincible. According to a series of articles in this week's issue of the science journal Nature, they endure afflictions that most people, even most atheltes, will never encounter.
Some athletes face perpetual exhaustion, others may be struggling with genetic defects. Add to the mix the heat and pollution in Athens, and these Olympic Games could prove to be the most physically demanding ever.
"Elite sport, a triumph of the human body over the laws of nature, pushes participants to the edge of possibilitiesand sometimes right over that edge," Nicola Jones, a Nature editor, writes.
Reluctant Test Species
Olympic athletes may be stretching the boundaries of normal physiology. But they are also a difficult breed to study. Many are reluctant to participate in scientific experiments because they do not want to interrupt their training regimes.
"Athletes don't want to be training with a thermometer up their backside," Alison Abbott, Nature's senior European correspondent, said in a telephone interview from Munich, Germany. As a result, she added, "There are a lot of things in sports biology that we don't know much about."
Take, for example, the effects of high-altitude training, a technique widely believed to improve performance. Here, scientific opinion is divided.
Some studies have shown high-altitude training to increase hemoglobin. (Found in red blood cells, hemoglobin carries oxygen to muscles. Therefore, an increase in hemoglobin may boost athletic performance.) Other studies have found no change in hemoglobin levels.
Not everyone is destined to become an elite athlete. "It's not a question of just being determined and dedicated," Abbott said. "That is absolutely not enough."
Some people's genes are preset for maximal athletic performance. Eero Mäntyranta, the 1964 Finnish cross-country skiing gold medalist, had a mutation in the gene associated with erythropoietin, a hormonal substance that stimulates the production of red blood cells. Sports scientists believe this accounted for his extraordinary stamina.
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