Erythropoietin

Erythropoietin (EPO) is a naturally occurring hormone that stimulates the production of new red blood cells (RBCs), a process called hematopoiesis. Athletes have used EPO to increase red blood cell mass as a way of gaining a competitive advantage, particularly in endurance sports.

RBCs deliver oxygen to peripheral tissues, including muscle. Exercising muscles use oxygen to produce energy. Well-trained muscles with adequate oxygen supplies can remain in aerobic metabolism longer. This means that the fuel that the body uses is metabolized efficiently with fewer ...