Amidst the news of Lance Armstrong’s doping scandal and allegations of his use of performance-enhancing substances, and the publication of the World Anti-Doping Association’s (WADA) 2013 Prohibited List which is to be effective January 1st 2013, comes the need to relook into doping, what out there counts as such, and what methods and substances are being used by athletes. The new list contains 12 prohibited/banned substances and methods ranging from the familiar anabolic agents, such as AAS (anabolic androgenic steroids), to ones that seem to belong in science fiction movies, like gene doping. Many of the items on the list are not new and their effects are well known.
What is trending in media right now is the use of Erythropoiesis-Stimulating Agents (EPO), blood doping to enhance oxygen transfer, and physical and chemical manipulation, such as the use of saline injected intravenously. Erythropoiesis refers to the production of red blood cells by the bone marrow due to a lack in oxygen detected by the kidneys. The kidneys then release erythropoietin to signal an increase in production of red blood cells and this hormone is endogenous or capable of being produced by the body naturally, while exogenous (not produced by the body naturally) EPO can be injected to increase an athlete’s endurance. The idea of this is to increase the efficiency of the oxygen delivery system by boosting blood oxygen levels, heart stroke volume, and enhancing the function of the lungs. The use of EPO is different from the traditional performance-enhancing drugs, as it does not have the dramatic effect on the body produced by anabolic steroids, which mimic the effect of testosterone to promote anabolism (protein synthesis and building cell tissue) and limit catabolism or muscle breakdown caused by cortisol. EPO focuses on increasing endurance and the benefits only show themselves in long, grueling events, such as long distance swimming, marathons, and cycling.
To think that the increase of something as arbitrary as the red blood cell count would raise performance enough that one athlete may outclass another seems silly at first. But through the course of many miles, someone who was “not previously known for his climbing, Armstrong was dominant in winning the stage to Sestriéres where he gained significant time on his rivals. Going into the final climb, Armstrong was behind several contenders but on the ascent soon caught and quickly passed them with seeming ease, rapidly leaving his competitors far behind” (Reasoned Decision, USADA). Blood doping, such as the withdrawal of blood, and later transfusion, aims to do the same as EPO, but both methods have their drawbacks. EPO and blood doping greatly increase an athlete’s hematocrit levels (volume percentage of red blood cells in blood), while blood doping has a further drawback as it decreases the amount of reticulocytes (immature red blood cells). This became the reason for injecting saline solutions and the implementation of hypoxic chambers to decrease hematocrit levels and increase natural EPO, respectively. During the 1990s, use of EPO ran high, as testing methods were almost non-existent, due to a lack of technology. Even today, testing for recombinant EPO using urine remains ineffective as the amount of endogenous EPO within urine is very low.
The World Anti-Doping Agency’s development using isoelectric focusing (distinguishing molecules from their isoelectric point, or point where a molecule carries no net electrical charge) to detect EPO usage proved to be effective initially, as it forced many abusers to change to micro-doses in order to cut down the time window for detection to 12-18 hours after injection. This, however, changed the ability for WADA to properly detect EPO, as WADA performed “EPO tests on more than 2,600 samples, only nine of them were found to be positive . The low numbers of athletes caught by the test are somewhat contradictory to the overall increase of mean hematocrit values since recombinant EPO became available.” By combining urine and blood analysis for the presence of EPO and high hematocrit levels, the accuracy of tests become higher, yet it remains an area for improvement for the future testing and the identification of substance abusers in sport.
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