Blood doping
Blood doping is the practice of boosting the number of red blood cells in the bloodstream in order to enhance athletic performance. Because such blood cells carry oxygen from the lungs to the muscles, a higher concentration in the blood can improve an athlete’s aerobic capacity (VO2 max) and endurance. Many methods of blood doping are illegal, particularly in professional sports.
Background
Blood doping is defined as the use of illicit products (i.e. erythropoietin (EPO), darbepoetin-alfa, hypoxia-inducible factor (HIF) stabilizers) and methods (i.e. increase aerobic capacity by maximizing the uptake of O2) in order to enhance the O2 transport of the body to the muscles.
The body undergoes aerobic respiration in order to provide sufficient delivery of O2 to the exercising skeletal muscles and the main determining factors are shown in figure 1. The rate maximum O2 uptake (O2max) depends on cardiac output, O2 extraction and hemoglobin mass. The cardiac output of an athlete is difficult to manipulate during competitions and the distribution of cardiac output is at the maximum rate (i.e. 80%) during competitions. In addition, the O2 extraction is approximately 90% at maximal exercise. Therefore, the only method to enhance the physical performance left is to increase the O2 content in the artery by enhancing the hemoglobin mass. In other words, hemoglobin concentration and blood volume contribute to hemoglobin mass.
