Earlier this month, the U.S. Anti-Doping Agency released a report laying out evidence that Lance Armstrong was at the center of a sophisticated cheating ring that helped him win seven Tour de France cycling titles.
Armstrong was cast out Monday by his sport, formally stripped of his seven titles and banned for life for his involvement.
According to the report, the key to this performance-enhancing conspiracy was blood doping. This is a term that the media throws around a lot, but what does it actually mean? How does it help enhance athletes' performances? And is it dangerous?
Dr. Prescott prescribes
“Blood doping” refers to any illicit method of boosting the levels of red blood cells in an athlete's bloodstream. This process allows muscles to work more efficiently, giving dopers an advantage over non-doping competitors, but it carries cardiovascular health risks.
Red blood cells carry oxygen through the bloodstream, so increasing their numbers ups the amount of oxygen delivered to the muscles. This results in less fatigue and more efficient performances, particularly in endurance events such as long-distance running and cycling.
Endurance athletes can naturally boost their bodies' red blood cell counts by training at high altitude. The lower air pressure and diminished oxygen content of the air cause the body to generate extra red blood cells, bumping up the hematocrit (the percentage of blood composed of red blood cells) up a few percentage points. Athletes, though, can get a bigger boost through two other prohibited methods, both of which Armstrong purportedly used.
Injections with erythropoietin (EPO), a naturally occurring hormone that biotech companies have made in large amounts for treatment of anemia in cancer and AIDS, stimulate the body to produce more red blood cells. The body metabolizes the hormone in four days, making it difficult to detect via testing. But the hormones' performance-boosting effects last for weeks.
Transfusions with a person's own blood can also bump up red blood cell counts. Using this approach, athletes draw and store their own blood during training, then re-inject red blood cells taken from the blood (they can be separated out using a centrifuge) before the competition. In the interim, the body has produced more red blood cells, so that the re-injected red cells create a higher volume of these oxygen carriers.
Other than looking for unnaturally high hematocrit, there currently is no accepted test to detect for transfusions with an athlete's own blood. But other circumstantial evidence — such as the presence in blood of plastic additives found in I.V. bags — has helped authorities sniff out this method of blood doping in the past.
The effects of blood doping are short-lived; when the body senses the unnatural levels of red cells in the blood, it attempts to return things to normal by not replacing the extra cells as they die. So that means that athletes who want to maintain the benefits of doping will engage in repeated cycles.
Ethics aside, doping carries health risks. The hard work of pushing unnaturally thickened blood through the veins increases the probability of cardiovascular events such as strokes or heart attacks, as well as kidney damage. Although doping may cut a few minutes from athletes' race times, it can also cut years from their lives.
Prescott, a physician and medical researcher, is president of the Oklahoma Medical Research Foundation. Cohen is a marathoner and OMRF's senior vice president and general counsel.