WEDNESDAY, May 28, 2003 (HealthDayNews) -- Blood doping can boost performance enough to propel a cross-country skier from 30th place to the medal podium in elite international competition.
And the practice appeared to be rampant among top skiers in the 2001 Nordic World Ski Championships, a new study concludes.
The research, published in the May issue of the Clinical Journal of Sport Medicine, found that more than a third of the top 50 finalists in the cross-country skiing competition -- and half the medal winners -- showed evidence that suggests illegal blood doping.
University of Alberta researchers analyzed blood samples from the top 50 competitors in nine races to test for abnormally high levels of oxygen-carrying cells in the blood. Athletes can use erythropoietin -- or EPO, a hormone that stimulates red blood cell production -- so the blood can carry more oxygen, an important factor in endurance, the study says.
International athletic federations now follow the Olympic Committee medical code, which recognizes only the presence of a banned substance in urine as proof of doping, the study's authors say. But current testing procedures are often ineffective in detecting EPO use, the study says.
So, detecting doping will require relying on measures such as blood tests measuring oxygen-carrying cells, the study concludes.
"Blood doping is both prevalent and effective in cross-country skiing, and current testing programs for blood doping are ineffective," the authors write. "The new formulations of erythropoietin leave athletes ... with the choice of competing 'clean' or doping to be able to compete with 'those other cheaters' who will not be caught by existing controls."
And it's unlikely blood doping is less common in endurance sports other than skiing, the study adds.
The world ski championships in Lahti, Finland, came the year before the Winter Olympics in Salt Lake City, Utah, where three cross-country skiers tested positive for blood doping, the study notes.
The researchers analyzed 203 blood samples from 146 of the skiers at Lahti. Overall, 36 percent of the top 50 finishers had abnormal blood test results indicating blood doping. Among medal winners, half had "highly abnormal" results, as did a third of those finishing from fourth to 10th place, the researchers found.
By contrast, among skiers finishing from 41st to 50th place, only 3 percent had "highly abnormal" results. And in the general population, that level would be expected in less than 1 percent, the researchers report.
In a World Cup or Olympic cross-country race, the top 50 skiers typically finish within 10 percent of the winning time, the researchers say. Blood doping can provide up to a 10 percent improvement in performance, "making it by far the most effective way to manipulate results in endurance sports," the study says.
Dr. Gary Wadler, a sports medicine specialist and an expert on doping, says the study highlights the need for better testing to detect cheating among athletes.
Elevated EPO levels show up in tests for only a few days, Wadler says, but the beneficial results -- improved performance -- can last for weeks. This raises a key question, he says: "Are the athletes learning to play the calendar rather than the game of sports?"
Wadler, a fellow of the American College of Sports Medicine and a medical adviser on performance-enhancing drugs to the White House Office of National Drug Control Policy, says use of EPO to improve performance is dangerous and can be fatal. The hormone, used medically to treat anemia, makes the blood unnaturally thick, leading to increased risk of heart attack and stroke, he says.
"It's a very serious health issue as well as an issue of unfair athletic advantage," Wadler says.
More information
For more on EPO, visit the University of Florida. To learn more about doping in sports, check out the World Anti-Doping Agency.
