Final answer:
Testosterone and other androgens stimulate an increase in red blood cell production, a process enhanced by the hormone erythropoietin (EPO), which can pose health risks when used for blood doping by athletes.
Step-by-step explanation:
Testosterone and other androgens have an erythropoietic stimulating effect which causes an increase in red blood cell production. This process is essential for maintaining an adequate number of erythrocytes (red blood cells) in the bloodstream, which are responsible for oxygen transport throughout the body.
Erythropoietin (EPO) is a hormone produced primarily by the kidneys in response to low oxygen levels in the bloodstream. Its primary function is to stimulate the bone marrow to produce more red blood cells, thereby increasing the oxygen-carrying capacity of the blood. Athletes have misused synthetic EPO as a performance-enhancing drug, known as blood doping, but this can lead to increased blood viscosity. This thickening of the blood can pose severe health risks, including the potential for heart attacks or strokes due to the strain on the circulatory system.