As we have seen, erythropoietin, often known as EPO, is a hormone secreted by the kidneys in response to reduced oxygen levels in the blood. One of the functions of EPO is stimulating the maturation of red blood cells in the bone marrow, thereby increasing oxygen delivery to muscles. Breath holding is an effective way of stimulating the release of EPO, allowing you to fuel your blood with increased levels of oxygen and enhance your sports performance. The concentration of EPO can increase by as much as 24 percent when the body is subjected to lower oxygen levels using breath-hold exercises.
