Blood doping is a method used by some athletes to enhance their performance by increasing the number of red blood cells in their bloodstream. This can improve oxygen delivery to muscles, allowing for better endurance and stamina during competitions. Techniques include transfusing blood or using substances like erythropoietin (EPO) to stimulate red blood cell production. While blood doping can provide a competitive edge, it is considered unethical and is banned by most sports organizations, including the International Olympic Committee. Athletes caught using these methods may face severe penalties, including disqualification and suspension from their sport.