blood doping

n.
The process of increasing the number of circulating red blood cells, either by transfusing an individual with blood that has been previously removed or by administering erythropoietin, in order to increase the oxygen-carrying capacity of the blood for improved athletic endurance. Also called blood boosting, blood packing.

A technique that athletes use to boost their stamina by injecting themselves with extra blood. Blood doping has been used to improve the performance of crosscountry skiers, marathoners, and triathletes. Blood doping is carried out in the belief that it increases the oxygen-carrying capacity of the circulatory system and thereby improves endurance. The blood may be obtained from the same individual (autotransfusion) or from another individual.

In autotransfusion, about a litre of blood is extracted usually some time before a competition so that the body has time to replace the lost blood. The blood is frozen for storage to reduce damage to red blood cells. After thawing, the stored blood is returned to the body immediately before competition to boost the red blood cell count. In addition to contravening the ethics of medicine and sport, this procedure carries a number of risks. These include the possibility of increasing the thickness of blood, making it more difficult to pump around the body and imposing an extra strain on the heart. The extra-thick blood may also damage the kidneys. When using donated blood, there is also a very real risk of transmission of infective diseases. Blood doping is banned by the International Olympic Committee. See also erythropoietin.

Any artificial means of increasing the total number of blood cells in the body, other than as a legitimate medical treatment. Blood doping is on the World Anti-Doping Agency's list of prohibited methods of enhancing oxygen transfer. Despite its prohibition, it is carried out by some athletes because it can significantly increase maximal oxygen uptake (VO₂ max) and therefore improve endurance. Blood doping is usually accomplished by transfusion of blood either previously donated by the individual (an autotransfusion or autologous transfusion), or by transfusion of blood of the same blood type from someone else (homologous transfusion). Typically, in autotransfusions of athletes, the blood (about 900 ml or more) is extracted 5-6 weeks before a major competition so that the body has an opportunity to replace the lost blood. The blood is frozen for storage to minimize destruction of the cells. Then the stored blood is transfused back immediately prior to the competition to boost the red cell count. In addition to contravening the ethics of medicine and sport, the procedure carries a number of risks. These include the possibility of increased blood viscosity, which may put an extra strain on the heart, the transmission of infectious diseases, kidney damage, and overload of the circulatory system. Other artificial methods enhancing the uptake, transport or delivery of oxygen are also on the World Anti-Doping Agency's Prohibited list. These methods include, but are not limited to, perfluorochemicals, efaproxiral, and modified haemoglobin products. See also erythropoietin.

This entry is from Wikipedia, the leading user-contributed encyclopedia. It may not have been reviewed by professional editors (see full disclaimer)