Athens Olympics May Be Most Physically Demanding Ever

Stefan Lovgren
for National Geographic News

August 5, 2004

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 possibilities—and 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.

Today's athletes also train harder than ever before. Roger Bannister, who in 1954 became the first person to run a mile in under 4 minutes, trained for only 35 minutes a day. "That's barely considered a warm-up today," Abbott writes in her article.

Overtraining

But what happens when athletes push themselves too hard?

Some athletes may develop a condition called Unexplained Underperformance Syndrome (UPS), or overtraining syndrome. Symptoms include increased rate of infection, general fatigue, muscle ache, and stomach problems. As many as one in ten athletes may develop UPS.

"Almost everyone recovers from UPS," Jim Giles, a Nature reporter who wrote about the condition, said in a telephone interview from London.

But UPS can ruin an athlete's preparation for major events. "One sports scientist told me that if an athlete gets it before competition, it's all over," Giles said.

What causes UPS is under heavy debate. According to one theory, athletes may damage muscle by overreaching. To deal with this damage to the tissue, levels of some cytokines—molecules used to exchange signals between cells—increase.

As well as calming inflammation, cytokines suppress the ability of immune system cells to attack pathogens, leaving athletes vulnerable to illness.

One precaution that athletes should take to avoid UPS is to rest at least six hours between training sessions, according to Michael Gleeson, a sports scientist at Loughborough University in Leicestershire, England.

"Psychological issues seem to be quite a big factor as well," Giles said. "But no one knows exactly how those contribute to the physiological changes."

Sudden Death

To some people, elite sports may be deadly. Last year, Cameroonian soccer player Marc-Vivien Foé died while playing a match. Seven months later, so did Hungarian footballer Miklos Feher.

Both athletes suffered from an inherited heart condition called hypertropic cardiomyopathy (HCM). It is the leading cause of sudden death in people under the age 30, according to Nature. The median age of HCM sufferers who die while engaged in sports is just 17 years old.

HCM is caused by the accumulation of an abnormal protein inside sarcomeres, a basic component of heart-muscle cells. This causes the cells to grow too large. As the muscles thicken, the heart can develop an irregular beat and runs the risk of stopping completely.

According to Nature, about 0.1 to 0.2 percent of people in the world have HCM. Each year about one percent of these people die. The extra strain of excessive exercise is believed to be able to trigger sudden death in people with HCM.

In Athens the Olympic athletes will also face human-made obstacles. The Greek capital, home to more than three million people, is one of Europe's most polluted cities.

Two pollutants of great concern are ozone and particulates (tiny bits of soot and other matter), both of which can irritate the lungs and cause asthmatic symptoms. On particularly bad days, the ozone levels in Athens far exceed the levels deemed healthy by the World Health Organization.

Outdoor athletes, such as cyclists, are most at risk. Elite athletes can cycle about 150 liters of air in and out of their lungs every minute during competition—ten times more than "normal" humans. This, of course, exposes them to more pollution. They also inhale much more deeply, taking pollutants into the deepest regions of the lungs, Nature writes.

But Athens's pollution problem may be lighter than that of the upcoming 2008 summer games in Beijing. There, the particulate concentration is three times higher than it is in Athens.

For more Olympics news, scroll down.