New York Times Julie Macur doesn't seem like a fangirl to me

[Parrot23]

....the overall uncertainty in the final estimated power is nearly 11%. Combine that with the uncertainty on the "supply side" of things, and it quickly becomes clear why attempting to use this approach to definitely identify who is/is not doping is a futile (yes, futile) endeavor.

It's quite likely the margins of error/interpretation in the biopassport well exceed 11%.

It's no slamdunk by any means but an interpretive method where members of the UCI expert committee can differ but come to a consensus on the basis of an evolving pattern of evidence and probabilities (there's likely a good deal of de facto monte carlo stuff being used in it in any event). Doesn't mean it's not science.

So you would say with that inherent margin of error/interpretation in the biopassport, let's toss it out as well? (Bayesian analysis is prob. illegitimate to you as well.)

And who is proferring the straw man that Tucker et al's approach is aimed at "definitely" identifying dopers but yourself?

 

[mastersracer]

seems most of these posts are failing to distinguish between rumor, speculation, and innuendo re Armstrong doping vs. whether the modeling effort provides any support for it. Re the Bayesian comment, a Bayesian theory of evidence suggests that the modeling effort provides no evidential support since the conditional probability H|D is no greater than the unconditional probability....

Re the biopassport comment, is there any documentation for the statement about error? I think the analogous case would be more akin to attempting to estimate blood parameter values from performance rather than actual samples.

 

[buckwheat]

Wow, I get all your posts now. The person who knows more about power output than anyone isn't sure about the answer to this question? No wonder you don't want to commit to a non-doped ceiling on watts/kg.

Strickland, Paul Sherwin and Phil I get, it's the money, their livelihood. But I don't get this.

Damn, I feel like I did when I was 8 years old my parents told me Santa Claus was not real. Say it aint so Andy?

Holy smokes! Guns ablazin. I didn't know that was coming.

 

[buckwheat]

seems most of these posts are failing to distinguish between rumor, speculation, and innuendo re Armstrong doping vs. whether the modeling effort provides any support for it. Re the Bayesian comment, a Bayesian theory of evidence suggests that the modeling effort provides no evidential support since the conditional probability H|D is no greater than the unconditional probability....

Re the biopassport comment, is there any documentation for the statement about error? I think the analogous case would be more akin to attempting to estimate blood parameter values from performance rather than actual samples.

You've never read Richard Feynman?

He hated lingo, words about words. My eyes are glazing over reading this silliness.

 

[I Watch Cycling In July]

What ARE you all talking about. Im lost.

Come on DIM, this is the anual debate about 'whether it's possible to tell if a rider is doping by estimating power numbers from how fast they ride/climb ....then comparing the numbers with estimates of maximum power achievable without doping?' Trying to get people to stop having the discussion would be as futile as trying to cancel Christmas....but we should prolly have a separate thread for it

@eigenvalu2 - Escarabajo did a monte carlo simulation to estimate the uncertainties in power numbers calculated from the Verbier ascent times in the 09 tour. Gave a nice handle on the magnitude of the uncertainties; I can't find it so I've pm'd him to post the link. That username is worthy of "sheldon cooper" BTW

 

[Realist]

I have no idea.

Do you count Michael Ashenden as a colleague? I think his publication record is pretty reasonable and his integrity is unimpeachable. Reading him say he had no doubt Lance was using EPO was tough for me to get over. If someone asked me if I thought Lance was using performance enhancing drugs, that would be the key reason I would not say "I have no idea". Certainly, I could say, "I have no insight beyond that which is a matter of public record".

 

[Parrot23]

Re the biopassport comment, is there any documentation for the statement about error? I think the analogous case would be more akin to attempting to estimate blood parameter values from performance rather than actual samples.

Of course not.

The fact UCI has an expert committee with disagreement and the need to come to a consenus on a pattern of evidence/probabilities from "actual samples" shows, yes, the margin of error is pretty wide. How can it be a matter of unimpeachable data: yes they doped; not they didn't? The data are subject to interpretation. There's no slam dunk.

There's a "naive positivist" premise lurking around here that the data should be black and white. Science would be very simple then.

The watts etc. estimation technique would simply be another tool for directing testing. Another source of probabilistic inferences. Doesn't mean it's not science (the very best of science, quantum mechanics, is probabilistic to its very core, lock stock and barrel).

 

[Le breton]

I challenge Andy Coggan

I used "*** u me" not to patronize you, but to emphasize the dangers inherent in making assumptions (notice that phrasing also indicts me).

If you have bothered to read the paper, you would realize that is not true.

Anyway, to return to the question at hand: while (as you correctly pointed out) not all terms in the equation contribute equally to any uncertainty in the final estimate, the uncertainties are largely independent and either additive or multiplicative in nature. As a consequence, the overall uncertainty is significantly larger than for any one term. For example, even if you can estimate air density, mass, rolling resistance, and wind speed to w/in 2%, the overall uncertainty in the final estimated power is nearly 11%. Combine that with the uncertainty on the "supply side" of things, and it quickly becomes clear why attempting to use this approach to definitely identify who is/is not doping is a futile (yes, futile) endeavor.

The following calculation, was posted on topica in 2004 and you did not challenge it at the time, I have modified it slightly so readers of this forum can follow more easily:

(the contributor) just got privileged information from a spectator on the
AdH TT who reads this forum (topica/wattage) but does not write.
Point 1 ( split time in l’Equipe newspaper) was really at km 1.7 ( as I thought), hence at
~725 m.a.s.l.
Point 2 was 50m after hairpin No 7, hence at ~ 1395m asl, km
9.15.
.....
Distance = 7 450m
Elevation 670m
time 21:03 = 1263 sec
slope =0.0899
v = 7450/1263 = 5.899m/s
Air density 28°C 1100m altitude -> 1.03
CdA 0.4 m^2
Crr = 0.0036
-----
70 kg cyclist + 8 kg equipment ( bike, shoes,... 1/2
bottle)

RESULT = 464 watts
+ 2.5% transmission losses -> 476 watts over 21 min

476/70 kg = 6.79 Watts/kg

There was no wind on that section of AdH that day.
(Higher up the last racers had to contend with a very noticeable wind)
Using only that lower part between 725 and 1395 m one does not need to take the physiological effects of altitude into consideration : effect on performance being almost imperceptible below 1500m (although Andy can find – no doubt – counterexamples).

Speed variations negligible.
Crr has been measured by extrapolation to V=0m/s on a similar French mountain road. Not very different from the 0.004 default figure in analyticcycling.com calculations.

With those parameters :

Gravity accounts for 405 watts, uncertainty under 1% (altitude gain) = 5.79 W/kg
Air resistance accounts for 42 watts = 0.6 W/kg
Rolling resistance for 16.5 watts = 0.23 W/kg

I consider changes in kinetic energy have a totally negligible effect until proven wrong.

Total 464 watts/kg = 6.63 W/kg

The uncertainty on gravity is about 0.5 to 1%, ie at most 0.06 W/kg
The uncertainty on Air resistance is at most about 10%, ie at most about 0.06 W/kg.
The uncertainty on rolling resistance at most 10%, ie at most 0.02 W/kg.

So the total uncertainty is about 0.09 watts/kg – 1.6%

Transmission losses, according to Ed Kyle are about 2.5%, although under ideal conditions they could be as low as 1.5%.

Therefore, on his time trial up AdH in 2004, LA developed 464 + 2.5 % = 476 watts (+/- 6 watts), or more precisely 6.8 W/kg (+/- 0.1 W/kg) during 1263 seconds in the section starting at 1700m and ending at 9150 m.

People seem to like to muddle the issue by introducing microscopic effects which play at a very low level of usually less than 1%, sinking to below 0.1% on a steady climb.

CONCLUSION

EVEN WHEN INCLUDING THE UNCERTAINTY ON TRANSMISSION LOSSES WE END UP WITH A TOTAL UNCERTAINTY ON THE CALCULATION OF THE ORDER OF 2%!
How are you going to do to bring that up to 11% Andy?

Of course, redoing the same calculation for a 71 or 72 kg or 73 kg or... will only modify the second decimal in W/kg

 

[acoggan]

Have you read FLTL?

FLTL = From Lance to Landis? If so, no.

 

[acoggan]

It's quite likely the margins of error/interpretation in the biopassport well exceed 11%.

It's no slamdunk by any means but an interpretive method where members of the UCI expert committee can differ but come to a consensus on the basis of an evolving pattern of evidence and probabilities (there's likely a good deal of de facto monte carlo stuff being used in it in any event). Doesn't mean it's not science.

So you would say with that inherent margin of error/interpretation in the biopassport, let's toss it out as well? (Bayesian analysis is prob. illegitimate to you as well.)

Ah, but there is a difference here that you are not acknowledging: the biopassport is not based upon the rider's actual performance. It is when you start to believe that you can precisely say "you can be this good, but no better" that the problems crop up.

And who is proferring the straw man that Tucker et al's approach is aimed at "definitely" identifying dopers but yourself?

You mean the Dr. Tucker that openly declared a power output of >6.2 W/kg for 40 min at the end of a stage "physiologically impossible"?

Seriously, though, my comment wasn't aimed at anyone in particular...just the general notion that you can, in fact, confidently identify dopers using this approach.

 

[acoggan]

Do you count Michael Ashenden as a colleague?

I did before he stopped doing research to become an anti-doping crusader.

I think his publication record is pretty reasonable and his integrity is unimpeachable. Reading him say he had no doubt Lance was using EPO was tough for me to get over. If someone asked me if I thought Lance was using performance enhancing drugs, that would be the key reason I would not say "I have no idea". Certainly, I could say, "I have no insight beyond that which is a matter of public record".

Ironic that you seem to believe that I should give weight to Ashenden's opinion while my own is so vociferously rejected.

Returning to the issue at hand: the reason that I said "I have no idea" is because I don't waste time idly speculating about matters that have essentially no impact on my personal life and about which I possess no special knowledge or insight. However, if in some weird twist I found myself sitting in judgement of Armstrong's guilt or innocence and had access to all available data, Asheden's opinion of the same would carry absolutely no weight with me.

 

[acoggan]

The watts etc. estimation technique would simply be another tool for directing testing.

Aren't those already apparently producing "impossible" power outputs already the focus of intense scrutiny as a result of being stage winners, GC contenders, etc.? Presumably they are...in which case, what is gained by estimating power output?

 

[acoggan]

The following calculation, was posted on topica in 2004 and you did not challenge it at the time, I have modified it slightly so readers of this forum can follow more easily:

(the contributor) just got privileged information from a spectator on the
AdH TT who reads this forum (topica/wattage) but does not write.
Point 1 ( split time in l’Equipe newspaper) was really at km 1.7 ( as I thought), hence at
~725 m.a.s.l.
Point 2 was 50m after hairpin No 7, hence at ~ 1395m asl, km
9.15.
.....
Distance = 7 450m
Elevation 670m
time 21:03 = 1263 sec
slope =0.0899
v = 7450/1263 = 5.899m/s
Air density 28°C 1100m altitude -> 1.03
CdA 0.4 m^2
Crr = 0.0036
-----
70 kg cyclist + 8 kg equipment ( bike, shoes,... 1/2
bottle)

RESULT = 464 watts
+ 2.5% transmission losses -> 476 watts over 21 min

476/70 kg = 6.79 Watts/kg

There was no wind on that section of AdH that day.
(Higher up the last racers had to contend with a very noticeable wind)
Using only that lower part between 725 and 1395 m one does not need to take the physiological effects of altitude into consideration : effect on performance being almost imperceptible below 1500m (although Andy can find – no doubt – counterexamples).

Speed variations negligible.
Crr has been measured by extrapolation to V=0m/s on a similar French mountain road. Not very different from the 0.004 default figure in analyticcycling.com calculations.

With those parameters :

Gravity accounts for 405 watts, uncertainty under 1% (altitude gain) = 5.79 W/kg
Air resistance accounts for 42 watts = 0.6 W/kg
Rolling resistance for 16.5 watts = 0.23 W/kg

I consider changes in kinetic energy have a totally negligible effect until proven wrong.

Total 464 watts/kg = 6.63 W/kg

The uncertainty on gravity is about 0.5 to 1%, ie at most 0.06 W/kg
The uncertainty on Air resistance is at most about 10%, ie at most about 0.06 W/kg.
The uncertainty on rolling resistance at most 10%, ie at most 0.02 W/kg.

So the total uncertainty is about 0.09 watts/kg – 1.6%

Transmission losses, according to Ed Kyle are about 2.5%, although under ideal conditions they could be as low as 1.5%.

Therefore, on his time trial up AdH in 2004, LA developed 464 + 2.5 % = 476 watts (+/- 6 watts), or more precisely 6.8 W/kg (+/- 0.1 W/kg) during 1263 seconds in the section starting at 1700m and ending at 9150 m.

People seem to like to muddle the issue by introducing microscopic effects which play at a very low level of usually less than 1%, sinking to below 0.1% on a steady climb.

CONCLUSION

EVEN WHEN INCLUDING THE UNCERTAINTY ON TRANSMISSION LOSSES WE END UP WITH A TOTAL UNCERTAINTY ON THE CALCULATION OF THE ORDER OF 2%!
How are you going to do to bring that up to 11% Andy?

The total uncertainty arrived at above is based upon their starting assumptions - my generic calculation (i.e., not aimed at the performance of Armstrong or anyone else in particular) was based upon different values for, e.g., CdA and more importantly by assuming a 2% margin of error in each of the variables and performing a standard propogation-of-error analysis.

In any case, thanks for dredging that up - I was going to point out to people that 1) contrary to what many here might believe, air resistance (and not, e.g., rolling resistance or drivetrain efficiency) is still the 2nd most important factor in determining the power required when climbing at such speeds (such that you need to account for, e.g., wind and drafting effects), and 2) the power required to overcome gravity and gravity alone, which is fairly easy to estimate accurately, is well within the range of plausibility from a physiological perspective. Hence, what is ultimately responsible for "putting someone over the line" are the estimates for the power required to overcome air resistance and, secondarily, rolling resistance...which is where almost all of the uncertainty lies.

 

[buckwheat]

I did before he stopped doing research to become an anti-doping crusader.



Ironic that you seem to believe that I should give weight to Ashenden's opinion while my own is so vociferously rejected.

Returning to the issue at hand: the reason that I said "I have no idea" is because I don't waste time idly speculating about matters that have essentially no impact on my personal life and about which I possess no special knowledge or insight. However, if in some weird twist I found myself sitting in judgement of Armstrong's guilt or innocence and had access to all available data, Asheden's opinion of the same would carry absolutely no weight with me.

Please read From Lance to Landis.

Secondly, familiarize yourself with Feynman. You're taking all this comfort in the equations but you're obviously coming up with the wrong answer. The correct answer is the only thing that matters.

 

[buckwheat]

I did before he stopped doing research to become an anti-doping crusader..

But Ashenden has the right answer and you don't. You keep falling back on this notion of uncertainty.

"Nothing is certain."

Richard Feynman

He was dealing with much more challenging problems than you're dealing with. Do you believe you can recreate exact conditions? At some point the mature person has to make some decisions and draw conclusions based on incomplete data. With you we do all this jerking off for absolutely nothing. Just babble.

Ironic that you seem to believe that I should give weight to Ashenden's opinion while my own is so vociferously rejected.

Returning to the issue at hand: the reason that I said "I have no idea" is because I don't waste time idly speculating about matters that have essentially no impact on my personal life and about which I possess no special knowledge or insight. However, if in some weird twist I found myself sitting in judgement of Armstrong's guilt or innocence and had access to all available data, Asheden's opinion of the same would carry absolutely no weight with me.

Good grief. What a copout. Life or bike races are not lived in a lab where everything can be taken into account.

You do realize that particle physics is a gigantic house of cards and that intuition, conjecture, guesses, speculation, and patchwork mathematics were essential in building the atomic bomb? This has and had much more importance than spade calling in athletic events, but physicists made those descisions rather than falling back on the bs of "uncertainty."

So if someone held a gun to your head and you had to say, LA, doped or not, what say you?

 

[Le breton]

Surely you are joking Mr Buckwheat

.............
"Nothing is certain."

Richard Feynman

He was dealing with much more challenging problems than you're dealing with.

You are right, quantum mechanically there is finite probability that you car will jump up in the air while you are indoors watching your screen.

 

[acoggan]

Please read From Lance to Landis.

As I indicated, I don't waste my time worrying about matters that have essentially no impact on my personal life.

 

[buckwheat]

People who are losing the forest for the trees, as Brodeal accurately portrayed the situation, need to read this primer.

http://en.wikipedia.org/wiki/Phenomenology_(science)

Phenomenology in physical sciences
There are cases in physics when it is not possible to derive a theory for describing observed results from the known first principles (such as Newton's laws of motion or Maxwell's equations of electromagnetism). There may be several reasons for this. For example, the underlying theory is not yet discovered, or the mathematics to describe the observations is too complex. In these cases sometimes simple algebraic expressions may be used to model the observations or experimental results. The algebraic model is then used to make predictions about the results of other observations or experiments. If the predictions made by the algebraic model are sufficiently accurate, they are often adopted by the scientific community despite the fact that the algebraic expressions themselves cannot be (or have not yet been) derived from the fundamental theory of that domain of knowledge.

The boundaries between theory and phenomenology, and between phenomenology and experiment, are fuzzy. Some philosophers of science, and in particular Nancy Cartwright argue that any fundamental laws of Nature are merely phenomenological generalizations.

 

[acoggan]

You do realize that particle physics is a gigantic house of cards and that intuition, conjecture, guesses, speculation, and patchwork mathematics were essential in building the atomic bomb? This has and had much more importance than spade calling in athletic events

Well there you go.

So if someone held a gun to your head and you had to say, LA, doped or not, what say you?

I'd do what any non-suicidal person would do: I'd lie and claim to be absolutely certain that he either did or did not, depending on my best guess as to what the person wanted to hear.

Short of that scenario, I am complete agnostic on the issue.

 

[buckwheat]

You are right, quantum mechanically there is finite probability that you car will jump up in the air while you are indoors watching your screen.

And now, back to "reality."

Do you believe there is consensus in this community?

 

[buckwheat]

Well there you go..

Yes, there are two sides to everything. You committing yourself to a decision here has as much consequence as ordering a vanilla or chocolate ice cream cone.

I'd do what any non-suicidal person would do: I'd lie and claim to be absolutely certain that he either did or did not, depending on my best guess as to what the person wanted to hear.

Short of that scenario, I am complete agnostic on the issue.

Nice evasion.

 

[buckwheat]

As I indicated, I don't waste my time worrying about matters that have essentially no impact on my personal life.

No guilty pleasures?

Bad movies? Star magazine? Golf? Riding a bike?

You're just concerned with pragmatic activities which further the life span of your own organism?

Why are you on cyclingnews forums?

To calculate power levels which may lead to the increased performance of the organism?

 

[buckwheat]

You are right, quantum mechanically there is finite probability that you car will jump up in the air while you are indoors watching your screen.

Well, yeah.

 

[Race Radio]

Short of that scenario, I am complete agnostic on the issue.

Hard to believe, when your mentor Coyle was a key participant in perpetuating the myth.

 

[Parrot23]

As I indicated, I don't waste my time worrying about matters that have essentially no impact on my personal life.

Well, then that's clear. "Citizenship" anybody?

I think a lot of fence-sitters on teams/teammates will change their views when their putative agnosticism is threatened with the charge of perjury. Meanwhile they are being studiously "objective", LOL.