I recently read that Lance Armstrong used EPO to win cycling championships. I wish to improve my ability to run long distances quickly. Will taking EPO be good for this, and are there any negative side-effects?
Erythropoietin (EPO) is a naturally occurring substance in the body that aids in red blood cell (RBC) production. It was originally developed as an external drug in the early 1900's to aid people with poor RBC production or other disease pathologies such as anemia.
By itself, EPO will do nothing to enhance your running ability. What it does do, is enable you to do more work by making available more oxygen to working muscles. This enables you to work harder, which in turn should make you faster. It is an enabler, not an instant result.
However, there are quite a lot of drawbacks to EPO supplementation in an otherwise normal person. One of the biggest is that when you artificially increase the RBC count in blood, it does not also increase the plasma/sera (liquid portions of the blood), so your blood becomes thicker. This makes it harder for the heart to pump the blood through the body, and when coupled with a lowered resting heart rate (A very common side effect of being fit), you highly increase your chance of stroke and death, especially when sleeping. There have been over 20 deaths in professional cycling in recent years linked to EPO use.
Obviously, people make their own choices, but if you are considering supplementing with EPO I would highly encourage you to research it thoroughly and understand the dangers and the risks that you take with your life by doing so.