Sportsscientists on EPO

[Tyler'sTwin]

EPO, short for erythropoeitin, is a hormone that is normally produced by the kidneys. It then has its effect on the bone marrow, which produces more red blood cells. So the effect of injecting synthetic EPO is to increase the body's natural production of red blood cells. Why would you want to do this? Well, the theory is that the red blood cells, which carry oxygen, are an important determinant of performance ability. That's because the oxygen is required by the muscles and the theory for fatigue during exercise is that if your muscles do not get sufficient oxygen, they rapidly fatigue. Connecting the dots, you get the logic that if you can increase the body's oxygen carrying capacity, you increase the ability to exercise before fatiguing.

And this is probably correct, but it might be a little over simplified. Why, for example, does EPO have it's greatest effects during endurance exercise like a Tour stage, where the cyclist is not really riding very close to their aerobic limit? In otherwords, if EPO was improving performance by increasing oxygen delivery to the muscle, then it would be most effective in the event where oxygen delivery is the potentially limiting factor. And when is oxygen potentially limiting? During shorter, higher intensity exercise, like 1500 m running events, perhaps up to about 15 minutes of exercise. Longer than this, and oxygen supply is not really limiting. So anyone who's ever ridden for 5 hours will tell you that you never really hit that limit, because you don't exercise near your maximum level. So we believe that EPO must have some other effect in addition to the one it has on the blood and oxygen levels.

Is there any evidence of this notion? That the primary benefits of EPO use is not an increase in red blood cells and the blood's O2 carrying ability, but something else? Has such an effect ever been observed? Why then would autologous blood doping be the real game changer in cycling today according to whistleblowers like Kohl and Landis? If this is true, then micro-dosing EPO should be a lot more effective than transfusions even if the actual increase in Hb is less significant, right? How sound is the assumption that an increase in the blood's oxygen carrying ability must have a greater impact on VO2 max than sub max efforts? And what evidence is there that it doesn't?

Edit: Link http://www.sportsscientists.com/2007/06/know-your-drugs-understanding-tour-de.html

 

[redtreviso]

""During shorter, higher intensity exercise, like 1500 m running events, perhaps up to about 15 minutes of exercise. """

or like 1/2 the climb of a mountain stage..enough to kill the field. Recovery to better than just fresh and rested between climbs..Little muscle fatigue caused by 100 miles approaching climbs.

 

[David Suro]

The text in the quote box is not entirely accurate.

It is true that there are rarely instances during a five hour ride when a cyclist is at his limit. A more accurate name for the "limit" is the lactate threshhold. Once an athlete surpasses the lactate threshhold, energy is produced via anaerobic as well as aerobic metabolic pathways. Producing energy via anaerobic pathways builds toxins in the body at a rate much faster than producing energy via aerobic pathways. The closer an athlete gets to the "limit" the more toxic the exercise. As more toxins accumulate in the body, energy production is decreased and the need for recovery time is increased.

As riders, we have all experienced this phenomenon. We are generally slower the day after an intense interval session and fresher and faster the day after an easy recovery ride.

Increased red blood cell concentration makes it such that more oxygen can be delivered to the muscles. As more exygen is delivered, an althlete can produce more energy while still being inside the "limit". Thus, there is greater power output with less toxic buildup of metabolic by-products. Riders with higher hematocrits can therefore produce more power and be farther within their "limit.

Higher hematocrit = equal power with less toxic buildup
Higher hematocrit = greater power within lactate threshhold
Higher hematocrit leads to better recovery due to decreased toxicity

Now, when a rider is at the limit during a grand tour, he is generally either sprinting, climbing, or time trialing.

For the GC contenders, the sprints don't matter much, if at all.

However, the GT's are won and lost in the time trials and the climbs. Those are conditions when the rider is at or near their lactate threshhold. The benefits of attaining a higher hematocrit through altitude training, blood transfusion, or EPO usage to improve climbing or time trial performance are enormous.

 

[The Hitch]

but in the tour do the cyclists not hit a limit when they hit 20% gradients in the mountains? Surely there they are hitting their aerobic limit? and they recover a bit when it flattens out or goes downhil.

In a marathon runners will go 20km/h for the entire race -the same effort and speed throughout, and that might not be close to their aerobic limit.

But the difference between cycling and all other racing is that in cycling the effort is increased and decreased throughout.

So while runners might run heavily throughout their race, in cycling they will be going lightly when they are drafting behind a group, and heavily for those 5 minutes or so when they are at the front. And when they start climbing, and hitting the really steep sections which are hard to get overm yet alone race over, and they decide to attack, they will be going very heavily and might be hitting their aerobic threshold there.

No???

 

[straydog]

Yes Hitch, they do hit their limits and they do vary their efforts but i think the relevant part of David Suro's excellent post in response to your question was....

Higher hematocrit = greater power within lactate threshhold

 

[Bobby700c]

Sounds like the 'Sports Scientists' don't know too much about competitive cycling to me.

 

[David Suro]

We all know that in this last Tour, there was only 39 second between first place and second place.

If we disregard all of the variables not associated with physiological capacity (the cobbles, the dropped chain, crashes, neutralized stage), the race between Contador and Schleck was even closer. They were virtually even in the mountains and Contador made gains in the TT's.

If Schleck had just a little more power while being within his limit or Contador a little less, the podium would have been reversed. The benefits of being able to produce even 1% more power while at lactate threshhold are significant, possibly even decisive in the case of this year's event.

Anyone who doubts the effectiveness of attaining a higher hematocrit by any method has to ask the questions:

If it doesn't matter, then why is there so much time, money, and effort spent on it. Why would the athletes risk penalty to dope for a higher hematocrit?

The answer is that they do it because it makes enough of a difference to be worth it.

 

[forty four]

The text in the quote box is not entirely accurate.

It is true that there are rarely instances during a five hour ride when a cyclist is at his limit. A more accurate name for the "limit" is the lactate threshhold. Once an athlete surpasses the lactate threshhold, energy is produced via anaerobic as well as aerobic metabolic pathways. Producing energy via anaerobic pathways builds toxins in the body at a rate much faster than producing energy via aerobic pathways. The closer an athlete gets to the "limit" the more toxic the exercise. As more toxins accumulate in the body, energy production is decreased and the need for recovery time is increased.

As riders, we have all experienced this phenomenon. We are generally slower the day after an intense interval session and fresher and faster the day after an easy recovery ride.

Increased red blood cell concentration makes it such that more oxygen can be delivered to the muscles. As more exygen is delivered, an althlete can produce more energy while still being inside the "limit". Thus, there is greater power output with less toxic buildup of metabolic by-products. Riders with higher hematocrits can therefore produce more power and be farther within their "limit.

Higher hematocrit = equal power with less toxic buildup
Higher hematocrit = greater power within lactate threshhold
Higher hematocrit leads to better recovery due to decreased toxicity

Now, when a rider is at the limit during a grand tour, he is generally either sprinting, climbing, or time trialing.

For the GC contenders, the sprints don't matter much, if at all.

However, the GT's are won and lost in the time trials and the climbs. Those are conditions when the rider is at or near their lactate threshhold. The benefits of attaining a higher hematocrit through altitude training, blood transfusion, or EPO usage to improve climbing or time trial performance are enormous.

exactly well put. the authors of the article missed some obvious points also having higher o2 levels circulating 24/7 cant hurt for recovery either.

 

[straydog]

We all know that in this last Tour, there was only 39 second between first place and second place.

If we disregard all of the variables not associated with physiological capacity (the cobbles, the dropped chain, crashes, neutralized stage), the race between Contador and Schleck was even closer. They were virtually even in the mountains and Contador made gains in the TT's.

If Schleck had just a little more power while being within his limit or Contador a little less, the podium would have been reversed. The benefits of being able to produce even 1% more power while at lactate threshhold are significant, possibly even decisive in the case of this year's event.

Anyone who doubts the effectiveness of attaining a higher hematocrit by any method has to ask the questions:

If it doesn't matter, then why is there so much time, money, and effort spent on it. Why would the athletes risk penalty to dope for a higher hematocrit?

The answer is that they do it because it makes enough of a difference to be worth it.

Exactly...again very well put....I would add that to many...the 50% threshold when it was set, wasn't the deterrent....it was the holy grail....

Now with the passport in place...the game is not to alert suspicion of doping...by avoiding any suspicious movement in haematocrit, haemaglobin, off scores etc

One of the downsides of EPO was that it's half life was long enough for it to possible be detected in tests relatively close to use....whereas the transfusions didn't and still don't, in that respect, carry the same risks.

 

[Tyler'sTwin]

Reading the comments, it appears as though their belief is grounded in an EPO study on amateurs, in which time to exhaustion at 80% of peak power output increased more (by ~50%) than peak power output (13%). I have no idea why this would indicate that EPO must have some unobserved performance enhancing mechanism besides more red blood cells.

 

[straydog]

Incidentally, there is some growing evidence of EPO's efficacy as an Anti Depressant. I wonder how many guys are going to manage to get TUE's for those mood swings? Could we see another Landis comeback?

 

[David Suro]

Do you have a link to the article stating EPO as an effective treatment for depression?

 

[djconnel]

It makes sense: when you're anemic, you feel crappy, foggy-headed, disoriented. It stands to reason a nice little boost to the RBC, even from a clinically nonanemic state, would make your brain as well as body happier.

 

[Neworld]

Do you have a link to the article stating EPO as an effective treatment for depression?

Mr. Suro,

Excellent comments. Thank you.

Are there a collection of Physiologists able to put together a list of banned substances and relate them to their percentage gain in performance or efficacy during long endurance races like a GT?

What I mean is:
1. EPO can raise your performance in cycling by 10-15%
2. Blood transfusions/ Increase in HCT up to 50% can raise your perf... ? %
3. GH/Test can ... by ? %

or are these variables too varied?

Just asking. I wonder as 'some' people seem to believe that all dopers dope the same, which I do not agree with. Some just use EPO while others with more money use the kitchen sink.

PS: EPO relative to depression therapy...I think those on winners on EPO surely are more elated than those who lose. Ha ha.

NW

 

[David Suro]

I don't know if such a list exists.

If it did, it would have to be updated frequently as new substances are used.

It would also be dangerous for a physiologist to publish information like that, since it would be like a "how to" guide for dopers. I think one of the most complete guides was the journal of Jan Ullrich.

It would be almost impossible to determine the % gains for each substance, since they seem to be used in combinations in modern doping programs.

Human physiology is not an exact science. Since we are all different to begin with, we have different strengths and weaknesses. Different athletes have different needs to reduce their weaknesses. They train differently and use different supplements, both legal and illegal.

Sorry for the vague answer, but it is a non-exact science.

 

[Neworld]

It would also be dangerous for a physiologist to publish information like that, since it would be like a "how to" guide for dopers. I think one of the most complete guides was the journal of Jan Ullrich.

Seriously, is there a Jan U journal? Is it in english that I could read?

Thank you for the last response.

NW

 

[David Suro]

There was information posted on this forum a long time ago about Ullrich's journal, or protocol for doping laid out by Fuentes and deciphered by Franke. I tried to find it, but couldn't. I have not read it myself, but other contributors claim it had pretty specific information regarding substances, doses, dates, etc.

If you can dig it up somewhere, post the link.

There was a thread that said something about a young racer using the information to design his own doping protocol. That is one of the reasons it is hard to find the specific information. It's kind of like a meth lab publishing their information about how to make the best stuff.

Given how speculative a lot of the information in forums can be, this might be complete fiction.

 

[Mr.38%]

Gains on EPO are highest in sub maximal efforts. You are able to do ten times as many repeats of supra maximal efforts. And you train on a whole new level regarding intensity and volume due to exceptional recovery.

EPO is the bomb for endurance athletes. WTF is wrong with these "sportsscientists"?

And by the way? Who gives a damn about HCT?

 

[smaryka]

The Sportscientists guys clearly aren't well-versed in how cycle racing works.

but in the tour do the cyclists not hit a limit when they hit 20% gradients in the mountains? Surely there they are hitting their aerobic limit? and they recover a bit when it flattens out or goes downhill.

Sure they "hit their limit" but they don't go over it, otherwise they blow. Those guys riding for their leader, pacing up the climb, are doing their VO2max or close to for 5-10 min or whatever it is, then they hit the limit and that's it for them. The GC guys need to be careful not to go over their limit or they will die like dogs too.

In a marathon runners will go 20km/h for the entire race -the same effort and speed throughout, and that might not be close to their aerobic limit.

But the difference between cycling and all other racing is that in cycling the effort is increased and decreased throughout.

So while runners might run heavily throughout their race, in cycling they will be going lightly when they are drafting behind a group, and heavily for those 5 minutes or so when they are at the front. And when they start climbing, and hitting the really steep sections which are hard to get overm yet alone race over, and they decide to attack, they will be going very heavily and might be hitting their aerobic threshold there.

Not exactly right, if you watch great marathoners in a close race, what seals the deal for the winner is the surging, which other runners can't follow. Note they can't surge for long, just long enough to drop the others. Very similar to climbing in this regard. There is still a drafting effect to be had in running, but not nearly as much as in cycling.

Note that NO contender, either in cycling nor marathon running, goes over their aerobic threshold and survives for long. This is because when you do, you die a quick death and go backwards rapidly. So any surges still fall right on the limit of aerobic/anaerobic so to speak. Only the final sprint really puts them into anaerobic territory -- puts them into a place where they can't recover and continue.

What I'm trying to say is that EPO is a very effective form of doping for both cycling and running.

 

[onefastgear]

The other thing that I have been thinking about, is that haemoglobin (the protein component of RBCs) is also a very effective carrier of CO2 (the byproduct of aerobic metabolism) as well as a major extracellular buffer (ie it resists changes in pH by being able to mop up additional H+ ions). This is part of the Haldane effect.

So as well as improving O2 delivery to tissues, it will carry away more CO2 that would ordinarily be possible, thus the pH change at the tissue level would be less and the muscles would be able to perform better at maximal levels given that the environment is less acidotic. Can any sports scientist discuss further?

Also, from a microdosing point of view, how quickly does an injection of EPO manifest in extra O2 carrying capacity? I imagine it's hours-days before the reticuocytes are out of the marrow and able to perform effectively. I remember that when Ashenden commented on the famous EPO positives, the samples were from tests done on critical stages (Prologue, TT, mountains). Does it make sense to take EPO in such a short time frame (ie presumably on the night before the stage)?

 

[acoggan]

Reading the comments, it appears as though their belief is grounded in an EPO study on amateurs, in which time to exhaustion at 80% of peak power output increased more (by ~50%) than peak power output (13%). I have no idea why this would indicate that EPO must have some unobserved performance enhancing mechanism besides more red blood cells.

It doesn't. OTOH, that same study also reported that time to fatigue was enhanced even at the same relative intensity, i.e., at the same percentage of VO2max. That unexpected observation*, along with their mentor's (much disputed) "central governor" hypothesis, would seem to be the basis for their hypothesis.

*In other studies in which convective O2 delivery has been independently manipulated, performance at the same percentage of VO2max, or markers thereof, has been a trailing indicator, not a leading one.

 

[acoggan]

Note that NO contender, either in cycling nor marathon running, goes over their aerobic threshold and survives for long. This is because when you do, you die a quick death and go backwards rapidly. So any surges still fall right on the limit of aerobic/anaerobic so to speak.

One notable exception, of course, being GT stages with mountain-top finishes, where a rider can afford to go "ten-tenths" to the point of utter failure. Indeed, if you get a gap on your competition you have an enormous incentive to do so, especially if there are time bonuses on the line.

(BTW, IIRC there were no such stages in the Tour this year...only one (?) finished on the top of a mountain, and Schlek and Contador effectively neutralized each other.)

 

[acoggan]

The other thing that I have been thinking about, is that haemoglobin (the protein component of RBCs) is also a very effective carrier of CO2 (the byproduct of aerobic metabolism) as well as a major extracellular buffer (ie it resists changes in pH by being able to mop up additional H+ ions). This is part of the Haldane effect.

So as well as improving O2 delivery to tissues, it will carry away more CO2 that would ordinarily be possible, thus the pH change at the tissue level would be less and the muscles would be able to perform better at maximal levels given that the environment is less acidotic. Can any sports scientist discuss further?

Since:

1) CO2 is highly diffusible through lipid membranes,
2) is carried largely in the form of bicarbonate and unchanged in solution, not by hemoglobin;
3) extracellular pH has little, if any, impact on physiological function/performance during aerobic exercise (cf. studies with bicarbonate loading)

I would not expect increasing hemoglobin to improve performance by the mechanism you hypothesize. In fact, I would not expect it to impact performance via any mechanism other than increasing convective O2 delivery (I suspect that the study cited as suggesting such an effect is a fluke observation).

 

[onefastgear]

acoggan, thanks for clearing that up. It was just a thought that popped into my head after some recent study.

I have enjoyed reading the healthy debate amongst those more informed than me regarding physiology in extreme exercise. Keep it coming.

 

[Mr.38%]

Also, from a microdosing point of view, how quickly does an injection of EPO manifest in extra O2 carrying capacity? I imagine it's hours-days before the reticuocytes are out of the marrow and able to perform effectively. I remember that when Ashenden commented on the famous EPO positives, the samples were from tests done on critical stages (Prologue, TT, mountains). Does it make sense to take EPO in such a short time frame (ie presumably on the night before the stage)?

Reti production will be stimulated almost "immediately" (as half life of i.v. epoetin alpha is just 6-8 hours). Small doses are even washed out completely during the ca. 10 hours time-window over night. Eris will have matured within a week.

Microdosing should be even more effective unit by unit. Huge amounts of (s.c.) EPO inhibit endogen production much more than small (i.v.) doses because of a) supranormal levels and b) insufficient supply of iron.