In many cases, doping increases the amount of hemoglobin in the bloodstream. Hemoglobin is an oxygen-carrying protein in the blood. Increasing hemoglobin allows higher amounts of oxygen to reach and fuel an athlete’s muscles. This can improve stamina and performance, particularly in long-distance events, such as running and cycling.
Doping is banned by the International Olympic Committee and other sports organizations and is considered to be illegal.
Types of Doping
The three most common types of blood doping are:
- Blood transfusions
- Injections of erythropoietin (EPO)
- Injections of synthetic oxygen carriers
Here are some more details about each of these types of blood doping:
Blood transfusions. In normal medical practice, patients may undergo blood transfusions to replace blood lost due to injury or surgery. Transfusions also are given to patients who suffer from low red blood cell counts caused by anemia, kidney failure, and other conditions or treatments.
Blood transfusions are used by athletes to boost performance. The main types are:
Autologous transfusion. This involves a transfusion of the athlete’s own blood, which is drawn and then stored for future use.
Homologous transfusion. In this type of transfusion, athletes use the blood of someone else with the same blood type.
EPO injections. EPO is a hormone produced by the kidney. It regulates the body’s production of red blood cells.
In medical practice, EPO injections are given to stimulate the production of red blood cells. For example, a synthetic EPO can be used to treat patients with anemia related to chronic or end-stage kidney disease.
Athletes using EPO do so to encourage their bodies to produce higher than normal amounts of red blood cells to enhance performance.
Synthetic oxygen carriers. These are chemicals that have the ability to carry oxygen. Examples are:
HBOCs (hemoglobin-based oxygen carriers)
Athletes use synthetic oxygen carriers to achieve the same performance-enhancing effects of other types of blood doping. Synthetic oxygen carriers have a legitimate medical use as emergency therapy. It is used when a patient needs a blood transfusion but: human blood is not available, there is a high risk of blood infection, or there isn’t enough time to find the proper match of blood type.
The Risks of Blood Doping
By increasing the number of red blood cells, blood doping causes the blood to thicken. This thickening forces the heart to work harder than normal to pump blood throughout the body. As a result, blood doping raises the risk of:
- Blood clot
- Heart attack
An estimated 20 cyclists are believed to have died as a result of blood doping over the past 25 years. Doping via transfusion carries additional risks.
Tainted blood can spread infectious diseases such as:
- Hepatitis B
- Hepatitis C
Over time, repeated blood transfusions can cause a dangerous buildup of iron in the body. Improperly stored blood and improperly administered transfusions can cause acute lung injury and bacterial infection.
The risks of EPO injections include:
- Hyperkalemia (potentially dangerous elevation of plasma potassium levels in the body)
- High blood pressure
- Mild flu-like symptoms
Athletes who use synthetic oxygen carriers have an increased risk of:
- Heart disease
- Heart attack
- blood clot