Lance's 2009 Blood Values - Much Ado about Nothing
Recently Lance Armstrong published his doping test results in an effort
to demonstrate that he's clean. I've said in the past, that doing this
is probably a mistake, especially for someone like Lance, because someone
is bound to come along and find this or that detail suspicious.
At any rate, we have this data from the Tour de France (extracted
from a table available
here).
| Date |
Hemoglobin |
Hematacrit |
Reticulocyte |
Comments |
| 7/2/09 |
14.3 |
42.8 |
0.5 |
pre-tour, in France |
| 7/10/09 |
14 |
41.3 |
0.5 |
stage 7, 1st mountain day, Contador attacks |
| 7/11/09 |
13.7 |
40.7 |
0.5 |
stage 8, 2nd day in Pyrenees |
| 7/13/09 |
no tests |
rest day |
| 7/14/09 |
14.4 |
43.1 |
0.7 |
stage 10, sprinters holiday |
| 7/20/09 |
14 |
41.7 |
0.5 |
rest day |
| 7/25/09 |
14.5 |
43 |
0.7 |
stage 20, Mount Ventoux |
In this case the first one of note to rise to the occasion was
Jakob Mørkebjerg, a Norwegian blood researcher. I first heard of the
story at
nyvelocity.com which has good coverage of the
story. The one link they seem to leave out is a more recent article
at cyclingnews.com.
Dr. Mørkebjerg has made three major points about Lance's blood values.
First, that his hematocrit and hemoglobin remain very constant throughout
the tour, rather than dropping as expected. Second, that his highest
hematocrits both occur after rest days, with the implication being that
he could hvae added a bit of blood on the rest days, and third that
his reticulocyte counts are low, especially in light of his steady
hematocrit and hemoglobin.
Everybody knows your crit drops during a Grand Tour
Lots of things that everybody knows turn out to be wrong. In this case,
I make no claims. But that cyclingnews article mentions a study
where this was demonstrated. The study involved seven athletes.
Maybe it was a tour that was hot at the beginning and cooler later,
in which case hydration issues would cause an apparent drop in crit
during the tour. I'm not specifically making this claim, I'm just saying
that I want to see a lot more data than one study of seven riders before
making any conclusion at all.
And before saying that a lack of a drop is a sign of doping, I'd
want to know how big of a drop is typical, and how much variation there
is. For this kind of statistical data, which is absolutely required
to draw this kind of conclusion, you'd need multiple studies each
involving scores of athletes. Otherwise there's no statistical
basis to decide what is normal and what is not. I admit at this point
that I haven't done any research here. I have no idea of the number or
quality of studies out there on this subject. But presumably Mørkebjerg
is familiar with the studies, and yet he only mentioned a single study
with seven riders. It may just be what fit in the article, but it doesn't
inspire confidence.
I'd also like to know more about why the crit would drop during a tour.
There are some obvious choices, but the mechanism would tell us more about
how much control an athlete has at preventing this problem. Does the
stress of a tour impact the die-off rate, the production rate, or both?
If the production rate is affected, is the limiting factor something
under nutritional control?
Increases in hematocrit after rest days
Recently I had the misfortune of having some medical issues, and had my
blood drawn twice in one week. A complete blood count was performed in
both cases. On Monday, my crit was 47, and on Thursday it was 43. The
doctor was neither surprised nor concerned.
There was no reason to suspect any actually loss of blood or red blood
cells. My assumption is that this difference is attributed to hydration,
because on Sunday I hadn't been drinking enough, maybe only 20 ounces or
so. The rest of the week I spent in my maximum hydration mode that I use
for illness, probably 80-100 ounces of fluid every day. There were no
other issues like diarrhea that would have had a larger impact on my fluid
levels.
Whether you like my hydration assumption or not, the fact that crit can
change that much in four days without my doctor thinking it's significant
says volumes about what these numbers mean.
In the entire month of the tour, the difference between Lances highest
and lowest values was 2.4. Again, if mild dehydration accounted for my
crit changes, just simple randomeness of hydration - when did Lance last
pee and drink, how much is he sweating - could account for the variations
we see. So on the issue
of increases in crit after rest days, this data lies completely within
the measurement noise. And because of the very small changes, it would
certainly be hard to argue for any kind
of useful or measurable performance gain from such a small increase
in blood values.
But even so one has to wonder what the natural effect on
hematocrit is from rest days. Certainly the obvious result during a rest
day would be a drop in crit: your body no longer has all that waste
to flush, and one presumes the athlete hydrates well, so the body
will retain more fluid. This retained fluid translates into a
larger blood volume without any increase in red blood cells. In
other words, a lower crit. But then after another hard day of
riding, does the crit jump back up to pre-rest-day values? Does
it take a couple of days to return to those values? Or does it
have an extra-quick rebound as the body is fully hydrated and willing
to release fluids more quickly? I don't know the answer, but the
point is, I'd hardly be surprised to see some influence on normal
crit values from a rest day.
Reticulocytes
Reticulocytes are new blood cells, and the measurement is the percentage of
his blood that is new. It's no surprise to see a low value going into
the tour - he was coming off of high-altitude training, and presumably
his body had already produced all the red blood cells it needed for altitude.
After returning to lower ground, he would not be producing many new red blood
cells, and the reticulocytes would be low.
Really though his crit isn't very high for someone who had been training
at altitude.
For the lack of attention this one has gotten, for my money it's still
the most interesting of the three arguments. This probably
says more about how uninteresting the other arguments are. At any
rate, normal reticulocycte counts are around 1%, but with a lot of
variation.
So the most interesting bit is that his reticulocytes are consistently low
and yet his crit doesn't drop. Still, this isn't much of a sign of doping
with crits this low. And, we have five days of tour blood values, meaning
we don't know what his reticulocyte count looked like the other 17 days.
Red blood cells are produced in the marrow, and the body can request an
increase in production by producing EPO. This tells the body to produce
more red blood cells. But it also tells the body to release the cells
that are already in production, even though they may not be "ripe".
So it's entirely possible, even normal, to see a higher reticulocyte count
for a few days, followed by a lower-than-normal count for a few days.
It's a good argument for testing some of these blood parameters every
single day during a tour, so you could actually make some meaningful
statements about how the blood is trending.
Conclusions
There's nothing here that screams "doping". There are things here that
seem slightly different from an ideal profile. It's unclear exactly
what normal should be, and exactly how slight these differences are.
Until someone is willing to cite studies and talk about the odds of these
slight variations occuring naturally, this all amounts to nothing.
If someone wants to pursue this to the last detail, they might try to
answer some basic questions:
Which samples were taken before the stage, and which
after? What kind of stage was ridden that day and the day before?
What kind of weather conditions? How did Lance perform? In my
opinion, even that is a waste of time. There's no way to account
for a rider doing a better job of hydrating one day versus the next,
simply because of perception of thirst, or mood. There's no way
to account for random luck of the body in how the electrolytes are
balanced one day versus the next, and how that affects fluid retention.
There's no way to account for the fact that there's always some complex
natural variation that for any practical purposes might as well be
considered random.
If there's a study out there that says that 99% of tour riders see
at least a five point drop in their crit during Grand Tours, then
I make take another look. But I'm pretty sure that doesn't exist.
Reader Comments
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1 comments:
At 2009/09/22 11:59
 wrote:
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Oddly, the latter part of this data has been removed from Lances blog where it had originally been posted. That could mean they're trying to hide something (which would be incredibly stupid since Pandora's Box can't be closed, or that they hope to quiet this story down by not feeding it. Whatever. At any rate, I've read about more about the bio passport program. Overall I think it's a good program. The description I read says that after using EPO, the body goes through a period of time where the crit (or hemaglobin count, which is preferred, and basically another way of counting the same thing) is higher than usual, and the reticulocyte count is lower than usual. Lance has half of this, with a lower (not by much) than usual reticulocyte count. His hemoglobin is not higher than usual, unless you think it should have fallen during the tour. But let's just suppose that Lance was taking small doses of EPO, to increase his red blood cells. But then he was increasing the volume of his blood with an IV plasma solution to keep his crit/hemoglobin lower and avoid suspicion. Well, yes, his data would look pretty much the same way they look. But of course, the big question to me is, how does altitude training compare to taking EPO? As far as I can tell the blood results should be identical. The mystery remains, why would his crit be this low after a few weeks of altitude training, and why wouldn't it drop even lower during the tour? One additional thought. If someone does do training at altitude and raises their hemoglobin/hematocrit, then don't they have a larger than normal proportion of fresh cells to old cells? And given that the cells last about 120 days, should their crit fall more slowly than someone who had not done altitude training? If nothing else, perhaps this reinforces the futility of trying to decipher anything from values this close to normal.
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