In 1993, U.S. Special Forces commanders at Fort Bragg started experimenting with blood doping, also known as blood loading. Special Forces operators would provide two units of whole blood, from which red blood cells would be extracted, concentrated, and stored under cold temperatures. 24 hours before a mission or battle, a small amount of red blood cells would be infused back into the soldier. Military scientists believe that the procedure increases the soldiers’s endurance and alertness because of the increase in the blood's capability to carry oxygen.