Red blood cells carry oxygen throughout the body, so it makes sense that if an athlete can increase their red blood cell count, they’ll deliver more oxygen to their muscles and perform at a higher level. Cyclists and other endurance athletes discovered that they could train longer and harder if they took the drug regularly.
Not surprisingly, taking EPO comes with significant risk. Yep, significant risk. Studies have shown that it increases the risk of events such as stroke, heart attack and pulmonary edema if abused.