Effect of tHbmass on VO2max

[Krebs cycle]

For anyone who is interested I've uploaded a review article by Nicole Prommer and Walter Schmidt on total hemoglobin mass.

Prommer & Schmidt - 2010
http://www.sendspace.com/file/4oka8r

Wrt to microdosing a key study which isn't cited in the review article, but is worth considering whilst reading this article is by Ashenden....

Ashenden et al., 2010
http://www.ncbi.nlm.nih.gov/pubmed/21336951
(12wks microdose = 10% increase in tHbmass)

The entire article is a must read (if you're interested in this stuff) but a final conclusion is that a change in tHbmass of 1g elicits approx a 4ml/min increase in VO2max.

So if you apply Ashenden's 10% increase from microdosing you get something along the lines of the following for a pro cyclist (but there is an assumption here that pro cyclists increase their tHb by the same amount as lesser trained individuals which is probably not the case due to already elevated total blood volume), which means that this is a "worst case scenario".

Lets go off the chart from figure 2B which is a tHbmass of 20g/kg which is about equal to 88 ml/kg/min (seems something is awry with the linear regression eqn in that fig though??)

for a 72kg athlete that would be a tHbmass of 1440g

10% increase from microdosing over 12wks = 144g

total increase in VO2 = 144 x 4 = 576 ml/min

72kg athlete with a VO2max of 88 therefore increases to 96 = 9.1% increase in VO2max.

Seems to match perfectly the results of EPO studies done on recreational level individuals but the question is whether or not pro cyclists can achieve the same kind of increase given that they already have massively elevated blood volumes from years of training.

 

[Dear Wiggo]

*YAWN*

Already discussed in great detail, with examples, a month ago here: http://captaintbag.tumblr.com/post/32385145751/captains-blood-dope-physiology-discussion

Already mentioned, linked to and discussed to death 4 days ago on the forum here: http://forum.cyclingnews.com/showthread.php?p=1059338#post1059338

 

[Alex Simmons/RST]

*YAWN*

Perhaps to those who spend their lives inside this pub, but some of us only pop in for a drink occasionally.

As I have said elsewhere, many people have networks that are not so well informed about such matters and don't like coming into pubs like this.

So when talking about such things in other pubs, I explain what difference to performance such undetectable doping practices have the potential to make, but use an example of someone they know and can relate to.

e.g., had I chosen to visit a seedy dopers hangout, then I could have been on the plane to London to race at the Paralympics, and be in medal contention. But they are not my ways, and I'm happy and proud to have raced at the level I was able to and achieve the modest level I did given my own particular circumstances.

 

[Maxiton]

This is great. Exactly the sort of stuff you expect to find in the Clinic. Thanks for posting.

 

[Realist]

Seems to match perfectly the results of EPO studies done on recreational level individuals but the question is whether or not pro cyclists can achieve the same kind of increase given that they already have massively elevated blood volumes from years of training.

Wouldn't much of the volume expansion come from plasma? Hence the term "exercise anaemia". Thus, one would expect a similar increase in performance in elites. Am I missing something here?

 

[Krebs cycle]

Wouldn't much of the volume expansion come from plasma? Hence the term "exercise anaemia". Thus, one would expect a similar increase in performance in elites. Am I missing something here?

Any sort of treatment that increases red cell volume will lead to a reduction in plasma renin activity and aldosterone. These hormones promote water retention, therefore, a decrease in these hormones leads to hemoconcentration ie: hemoglobin concentration [Hb] rises. This will flag the biopassport unless corrected so the only way around it is to know exactly when the testers are coming and be ready with a plasma volume expander. Normally, about 2/3 of the increase in VO2max is attributed to the increase in red cell mass whereas about 1/3 is attributed to the hemoconcentration (ie: content of oxygen per liter of blood goes up when [Hb] goes up) so if athletes are using plasma volume expanders all the time to mask the high [Hb] then it will lower the increase in VO2max normally seen. So our 9% improvement goes down to 6% or thereabouts. Alternatively, you could just dope less if you didn't want to take the risk of having your [Hb] go through the roof. But that would of course decrease the performance enhancement (kind of like how the TdF is going slower nowadays).

I was using the theoretical maximum as a case scenario, but I don't believe it is so easy to get such large increases in VO2max when your blood volume starting point is already fully maxed out from years of endurance training. If it was possible using current methods (ie: microdosing and perhaps using "micro" transfusions) to obtain a 4 or 5% increase in VO2max well then if you're a pro cyclist at 82 ml/kg then that only elevates you up to 86 or thereabouts. So some other superior physiological speciman with a VO2max of 87 ml/kg (for example Cadel Evans), still has a small advantage in terms of aerobic energy production.