This month, some of the favorites to win the Tour de France endurance bicycle race were prevented from entering because of suspicion that they may have taken drugs or had blood transfusions to raise their red blood cell counts. That brings up the accusation that Lance Armstrong, possibly the most dominant endurance bicycle racer of all time, took blood boosting drugs when he won the first of his seven Tour De France victories.

The allegation is that Lance Armstrong's urine, kept in storage for six years, had a positive test for EPO, a restricted drug that raises blood levels of oxygen-carrying and performance-enhancing hemoglobin. An article published in this month's issue of the prestigious medical journal, Blood (June 15, 2006) shows that after competing in any athletic event, any athlete could have a false positive urine test for EPO.

The test for EPO is done by injecting the protein, EPO, into animals so that their bodies produce special proteins called antibodies that attach to EPO. The antibodies are put on a special plate, and the test urine is added. If the urine contains EPO, a band consisting of the antibody tied to the EPO appears on the special plate.

Researchers at Catholic University of Leuven in Belgium showed that "this widely used test can occasionally lead to the false-positive detection of EPO in postexercise, protein-rich urine." Any athlete can have a false positive test with this procedure. Most people with healthy kidneys do not spill protein in their urine, but after strenuous exercise, athletes with normal kidneys often spill protein into their urine. For example, more than 80 percent of runners spilled protein into their urines after running the Boston Marathon. The authors state that the antibodies that are used in the test can attach to any protein in the urine, not just EPO.

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Dr. Gabe Mirkin has been a radio talk show host for 25 years and practicing physician for more than 40 years; he is board certified in four specialties, including sports medicine. Read or listen to hundreds of his fitness and health reports -- and the FREE Good Food Book -- at http://www.DrMirkin.com