Here in Part 2, I’ll still be using cycling as the example, and be diving into more pointed examples of doping as well as how and why doping is actually beneficial. We all know doping in its various forms enhances performance. However, understanding how doping works can be fascinating stuff and provides some logical insight into why athletes decide to cross the line when they know that unless they do, they will get shelled race after race. This is no way justifies or excuses the decision to cross that line. If an athlete cheats, he or she should be banned from sport for life. Full stop.
WADA, the World Anti-Doping Agency, defines doping as “The misuse of certain techniques and/or substances to increase one’s red blood cell mass, which allows the body to transport more O2 to muscles and therefore increase stamina and performance.” As discussed in Part 1, blood doping defined as the removal of one’s blood, that blood then being stored and reinjected at a later time to boost red blood cell mass, was en vogue in the 1980s. Starting in the 1990s, the blood doping we are more familiar with would be the abuse of EPO.
Francesco Conconi, famous for the Conconi Test for establishing lactate threshold, is regarded as the father of modern blood doping. Through the 1980s, Conconi increased the performance of athletes through both legal and illegal methods through his work at the University of Ferrara. Michele Ferrari, the infamous doctor who doped Lance Armstrong to his 7 Tour de France victories, was Conconi’s prize student (Luigi Cecchini, who worked with Bjarne Riis, Jan Ullrich, Michele Bartoli, Alessandro Petacchi, and Tyler Hamilton, among many others, was another Conconi disciple). Not only did these two doctors experiment on the athletes they helped, they also experimented on themselves (they were avid cyclists). The most notable athletic performance linked to Conconi and Ferrari in the 1980s was Francesco Moser’s 1984 breaking of the world hour record on the velodrome, accomplished with the boost of blood transfusions (legal at the time, though still considered cheating by many). Given that blood doping was legal at the time, we need to remember that these doctors and others were of the mindset that they were making scientific contributions to the world of Sport. They were finding boundaries and determining how to blow through them to further find the limit of human performance. Unfortunately, their mindsets didn’t change as the rules around blood doping evolved, even when athletes started dying from doping practices.
Blood Doping Basics
Now let’s look at exactly how blood doping helps athletes improve their performances. If you ever took an exercise physiology course, then you’re probably familiar with the Fick Equation, which determines the rate at which a person utilizes oxygen, also known as VO2max (volume of O2 uptake).
O2max = Qmax x a-VO2max
This states that the maximum rate of oxygen uptake (O2max) is the product of a high cardiac output (Q) and a wide difference for arterial-venous oxygen (a-VO2max) -- the oxygen content in the arterial and venous blood.
Aerobic capacity is the crux of determining success in endurance sports. Improvements to aerobic capacity are tied directly to how much blood – and, thus, O2-carrying red blood cells – the heart pumps out to the working muscles. Remember, O2 is the fuel of the working muscles and is the limiter to how hard an athlete can work and for how long.
We tend to think of aerobic capacity as our “all day” pace, when we keep our HR in our L1 & L2 aerobic zones. It’s not. Aerobic capacity is synonymous with VO2max. Oskar Svendsen reportedly has the highest recorded VO2max in a human at 97.5ml/kg/min. Greg LeMond’s VO2max was 92.5 and Lance Armstrong’s was 84, while Cadel Evans had a VO2max of 88. Now, a high VO2max value does not guarantee success, but it is used as an indicator as to what an athletes potential can be. For example, the story goes that Mark Cavendish’s VO2max and lactate threshold were so low that he was written off. VO2max is largely genetically predisposed. There’s not a lot you can do to influence it, except two things – either reduce your bodyweight; or increase the mass of the hemoglobin in your blood. So, imagine top athletes who attack this from both angles at once, and you start to get an idea of just how powerful blood doping can be as a way to dramatically impact athletic performance.
High delivery of O2 to the working muscles and then the use of that O2 are the determinant factors in athletic performance. Cardiac output and O2 extraction from the blood are genetically determined and damn near impossible to influence. Cardiac output is our heart beat and our max HR is pretty much locked and also gradually declines with age. Stroke volume – how much blood is pumped per heart beat – is also pretty much predetermined genetically. The respiratory capacity of the mitochondria is inherited from your mother. Lastly, O2 extraction is about 90% at maximal effort and is also near-impossible to change. So, we are left with two things that can be manipulated to increase performance – hemoglobin concentration and blood volume. This is the basis of blood doping.
Transfusions versus EPO
Athletes can either use blood transfusions or inject EPO to increase the red blood cell count – and, thus, O2-carrying capacity – in their blood. Both result in the same benefits to the athlete, despite the differences in how the body reacts to the two practices. It’s my understanding that transfusions elicit an immediate boost in hematocrit of a handful of points while EPO creates more of a slow rise. Tyler Hamilton’s book is pretty eye-opening and fascinating. As he describes it, “The key to riding with a BB (blood bag) is that you have to push past all the warning signs, past all the usual walls. You get to that place beyond your edge, the pace where you’ve fallen off a thousand times, and all of a sudden you can hang in there.” Rather than surviving, you’re competing and even dictating the race.
Altitude training is mildly effective in increasing the body’s red blood cell production, but the body has natural checks-and-balances in place so adaptation is slow (and safe). Since altitude training is legal, many athletes take advantage of both living/training at altitude as well as things like altitude tents. There’s also the premise of “live high, train low” that some athletes practice. For example, some distance runners live in Flagstaff, AZ (near 8,000ft elevation) and make the long drive to Phoenix down at 1,000ft for their key workouts. The premise is that they gain the benefits of living at altitude and then apply those gains at a lower altitude so they can train faster than possible at higher elevations.
Transfusing blood gets a little tricky to detect. There are two types – autologous and homologous. The former is when the athlete takes his or her own blood out and then puts it back in; the latter is when the athlete uses donor blood. In using donor blood, it is obviously critical to leverage the same blood type, otherwise the body will flag it as foreign material, attack it and destroy it. Using incompatible blood could also kill you.
Homologous transfusions can now fairly easily be detected in drug testing because while the donor blood is the same type of blood as the athlete’s there are still some genetic dissimilarities which are easy to flag. Before detection was available, the reason athletes used homologous transfusions was because this allowed those athletes to avoid the temporary dip in performance due to extracting their own blood. When you extract about 15% of your blood volume, performance takes a big hit until the body accounts for that deficit by topping off the blood tank.
It’s more difficult to detect an autologous transfusion because it is the athlete’s own blood being transfused. While there are more red blood cells carrying more O2 to the working muscles, the hematocrit percent does not materially change because the increase in red blood cells is commensurate with an increase in blood volume as well.
While the benefits of transfusions are fairly immediate, as discussed above, it takes 4-6 weeks of regular EPO use to achieve measurable upticks in performance. What’s interesting is that more is not better with EPO administration. In other words, to provide the most efficient red blood cell production, there are fairly tight parameters around how much EPO to administer above the athlete’s baseline hematocrit levels. Injecting higher levels is like taking a bunch of multi-vitamins resulting in bright yellow urine – the excess is purged and therefore wasted. On the flipside, injecting too little EPO does not sufficiently stimulate the body to produce more red blood cells, also resulting in wastage.
EPO used to be readily available without a prescription across Europe (and, I’m sure, other parts of the world). You could literally walk into a pharmacy and ask the pharmacist to give you a box of EPO vials without any sort of prescription required. This is part of the reason why EPO exploded into the endurance world. And, before it was detectable and banned, athletes used to administer high doses multiple times a week, resulting in hematocrit values well in excess of 50%. In fact, Bjarne Riis was famously dubbed “Mr. 60%”, a direct reference to his hematocrit level through EPO use.
Today, athletes continue to use EPO (yes, they do), but instead revert to micro-dosing. Micro-dosing begins in the same manner as the old practices, with high doses to create a nice spike in hematocrit. But, then, that higher level is maintained with continued low doses. Studies show that through micro-dosing, athletes can realize an increase to their maximal O2 carrying capacity of 6-12% when their hematocrit is increased to 50% (remember that magical threshold the UCI instituted as a “safe” threshold?). However, the punch line here is that due to a 6-12% increase in O2 carrying capacity, time to exhaustion (as measured in the lab) increases by as much as 50%! You can find way more resources than you could possibly want to read on the subject here.
Again, without condoning the practice of blood doping in any capacity, it is at least evident as to why so many athletes chose and still choose to leverage it for performance enhancement. A little boost in hematocrit brings with it an exponential increase in capacity at threshold. That’s a very tempting apple from which to take a bite.
I thought this would be just a two-part post. But, there will be a third post. In Part 3, I’ll tell a few stories about blood doping’s use and also try to shed some light on just how rampant the use was of transfusions and EPO.