Lance Armstrong Confesses to PEDs: What Is Erythropoietin (EPO) Blood Doping?

Dave Siebert, M.D.@DaveMSiebertFeatured ColumnistJanuary 16, 2013

AUSTIN, TX - JANUARY 14:  In this handout photo provided by the Oprah Winfrey Network, Oprah Winfrey (not pictured) speaks with Lance Armstrong during an interview regarding the controversy surrounding his cycling career January 14, 2013 in Austin, Texas.  Oprah Winfrey’s exclusive no-holds-barred interview with Lance Armstrong, 'Oprah and Lance Armstrong: The Worldwide Exclusive,' has expanded to air as a two-night event on OWN: Oprah Winfrey Network.  The special episode of 'Oprah’s Next Chapter' will air Thursday, January 17 from 9-10:30 p.m. ET/PT (as previously announced) and Friday, January 18 at 9 p.m. ET/PT. The interview will be simultaneously streamed LIVE worldwide both nights on Oprah.com.  (Photo by George Burns/Oprah Winfrey Network via Getty Images)
Handout/Getty Images

One of the longest-running sports stories of the past decade started to come to an end on Monday, Jan. 14, when Lance Armstrong confessed to using performance-enhancing drugs during his career.

According to the Associated Press, a source—speaking on condition of anonymity due to the fact that the interview had yet to air—said that Armstrong admitted to performance-enhancing drug use during an exclusive talk with Oprah Winfrey.

Armstrong—winner of Le Tour De France seven straight years from 1999-2005 and testicular cancer survivor—received a lifetime ban from competition by the United States Anti-Doping Agency (USADA) last year after he refused to continue to fight the allegations being laid against him. The USADA—under the influence of its CEO Travis Tygart—also stripped Armstrong of his titles at the time.

Later, Armstrong voluntarily stepped down from his position as chairman of Livestrong, his charitable cancer research foundation that has raised significant amounts of money to combat the disease since its founding in 1997.

It's a shame that Armstrong's admission to performance-enhancing drug use forever taints his legacy, but it's also confirmed the suspicions of countless competitors and officials that have swirled for years.

Armstrong has been connected to many drugs over time, but one of the most well-known drugs he reportedly used is the so-called "EPO."

A synthetic version of the natural hormone erythropoietin, EPO is an extremely effective drug that is widely prescribed by the medical community to treat a number of health conditions and diseases. It is also one of the most popular but banned PEDs. Its illegal use is especially widespread in the endurance sports community, most notably in professional cycling.

Why is that the case?

Simple. Outside EPO use—called exogenous use—artificially increases endurance and stamina. It does so by increasing the oxygen-carrying ability of the blood.

Human blood is made up of two large components—cells and plasma. Plasma—roughly 55 percent of the blood's volume—is mostly water and carries proteins and nutrients. The remaining 45 percent or so is composed of cells, the vast majority of which are red blood cells (RBCs).

The sole function of RBCs is to carry oxygen. They do so for the entirety of their roughly 120-day-long lifespan, picking up oxygen in the lungs and dropping it off in muscles, tissues and organs throughout the body. They also remove carbon dioxide from the body, carrying it away from tissues to be exhaled from the lungs. 

As RBCs die, they are continually replaced. The human body is extremely good at detecting RBC levels, and under normal conditions, it manufactures them at a rate equal to the breakdown rate.

However, using artificial EPO dramatically alters the body's normal RBC regulatory systems.

Though it remains unclear as to how exactly the body does so, decreased oxygen in the blood signals it to produce more RBCs than normal. The current theory states that low oxygen stimulates the production of erythropoietin by the kidneys.

Erythropoietin then travels to the bone marrow—where all blood cells are made—and revs up the production of RBCs. More RBCs means more oxygen can be picked up in the lungs and used by the body.

Nevertheless, the body tightly controls how much erythropoietin is produced in the kidneys, keeping the portion of blood made up by RBCs—called the "hematocrit"— at about 40 to 45 percent.

That said, people living at high altitudes may have higher hematocrits due to the lower levels of oxygen in the atmosphere at higher elevations. Additionally, someone traveling from low to high altitude will begin to produce more erythropoietin—and therefore more RBCs—over a period of a few days.

Yet, what if they inject themselves with extra, artificial erythropoietin? That is where Armstrong and countless other professional cyclists come into play.

By adding extra EPO to the blood via injection, an athlete artificially increases the amount of RBCs circulating in his or her blood, sidestepping the body's regulatory mechanisms. Abnormally high RBC levels means abnormally high oxygen delivery to muscles, allowing them to work longer and harder than before.

In a sport like competitive cycling that uses about 50 percent of the body's muscle mass—the legs—at full capacity for hours at a time, EPO use can provide for a huge advantage over the field.

And why does the cycling community care about EPO use?

Simple—it is an unnatural method of boosting performance. Medically speaking, however, too many RBCs—a condition called "polycythemia"—can cause problems just as severe as those caused by too few.

Polycythemia is a disease in and of itself that requires treatment. A higher proportion of cells when compared to the watery plasma causes the blood to be thicker and move slower, leading to clots. Blood clots can be life-threatening, as they can cause strokes and heart attacks, among other conditions.

In other words, exogenous EPO use directly produces a disease state. Nevertheless, calculated, timed and scientific use of EPO can make that disease state nearly undetectable.

Armstrong and his team figured that out and took advantage. Though Armstrong frequently cited his numerous negative drug tests as his primary defense against the allegations laid on him by the USADA, those tests obviously lied.

How can that be?

There are a number of ways that athletes can circumvent positive drug tests, a problem that has become more apparent in recent years and is the subject of an entirely different discussion.

To evade a positive test for EPO, athletes need to avoid being detected as having a hematocrit of 50 percent or higher—a level implying suspiciously high RBC levels in the blood.

To do so, athletes can use saline infusions—directly adding salt water to the blood through an IV.  That way, an athlete can dilute their blood to avoid an abnormally high hematocrit but still reap the benefits of the extra RBCs present.

They can also inject EPO directly into their veins, allowing it to be cleared from the body more quickly and less likely to be picked up in urine tests—but not before it works its magic.

Additionally, athletes can remove their own blood temporarily, allow their body to make up for the difference and add the removed blood back into their blood stream immediately prior to racing. This method of "self blood doping" remains undetectable by current laboratory testing.

It will be interesting to see if Armstrong goes into detail during his interview with Oprah about how he evaded testing positive.

However, admitting his guilt is more than enough.

With it, one of the sport's icons of the late-1990s and early-2000s—a champion and cancer survivor—fell from the rafters of clean competition, representing the latest victim to succumb to the temptation of performance-enhancing drugs.

Unfortunately, he won't be the last.

In today's era of incredibly powerful synthetic chemistry that is becoming more and more advanced, it is difficult to look at any professional athlete and confidently state that he or she is clean.

Whether it be frank PED use or circumventing the rules in some other way, athletic competition will be tainted by doubts for some time still. And when new urine or blood tests to detect cheating come out, new ways of avoiding those tests will assuredly soon follow.

As a result, the use of PEDs has become so commonplace that it is no longer shocking when the next athlete is accused. After all, as the saying goes, "If you aren't cheating, you aren't trying." These days, far too many athletes are taking that line of thinking much too seriously.

Dave Siebert is a medical/injury Featured Columnist for Bleacher Report who will graduate from medical school in June. He plans to specialize in both Family Medicine and Primary Care (non-operative) Sports Medicine. The medical information discussed above is based on his own knowledge.


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