Blood doping is a way of increasing the number of red blood cells in the bloodstream. This is done to improve athletic performance. Because blood cells carry oxygen from the lungs to the muscles, a having more red cells in the blood can improve an athlete’s aerobic capacity (VO2 max) and endurance. Many methods of blood doping are illegal, particularly in professional sport.
There are a number of different methods. Frozen blood taken from the individual previously can be used for a later transplant; packed red cells from a compatible donor may be used, and blood substitutes may be used. The growth area in illegal blood doping of athletes is blood substitutes.