Critical Power Study of GT Winners

[Merckx index]

A link to this study has already been posted here, and some discussion of it has begun, but I think it deserves its own thread. I found it very interesting. Among the more provocative conclusions:

1) Contador and Froome had essentially equal critical power (CP), a measure of aerobic capacity and derived power, in the 2013 TDF. The distinguishing factor was anaerobic energy/reserves (AEC in the paper). Froome’s was > 80% higher.

2) Contador in 2009 had 4% higher CP than he did in 2013, and more than double AEC. Contador in 2009 would have easily beaten Froome in 2013.

3) Froome’s CP in 2013 TDF was relatively low compared to that of past winners, including Lemond and others assumed to be clean (though no figures are provided for these).

4) Horner’s 2013 Vuelta CP was higher than that of any other rider in this study except Indurain in the height of the EPO era. His V02 max calculated from his CP was almost 90, and if not for a relatively low AEC, his numbers suggest he would blow Froome and just about anyone else out of the water.

Though the author does not make any definitive doping conclusions, it’s pretty clear he thinks his analysis is consistent with Froome being clean, while Horner looks very suspicious. However, these conclusions are based on their CPs, which as measures of aerobic power, are mostly relevant to blood doping. He shows AEC to be a key factor, and this certainly raises the question of whether certain doping methods could be used to enhance this. One would also love to see this kind of analysis on Froome pre-2011 Vuelta.

To play the devil's advocate here, if I were to assume everyone here is doping, it would seem that:

1) Froome has avoided blood doping in favor of some other program than enhances anaerobic reserves (AEC)
2) Horner has stayed with blood doping but hasn't tried/isn't aware of enhancement of AEC
3) Contador in 2009 was using both methods. In 2013 he was using blood doping less, and AEC enhancement not at all.

If these scenarios don't seem entirely consistent or make sense, that's my point. Contador, in particular, as noted above, had a much higher AEC in 2009 than in 2013. Why? If this can be enhanced by doping, and if Froome were doing it in 2013, why wasn't Contador? And Horner? If it can't be enhanced much, and is mostly a natural trait, why did AC experience such a huge dropoff between 2009 and 2013, much more than his decrease in CP?

Finally, it should be emphasized that the author necessarily engaged in a selection process in picking out climbs he thought were representative of the rider's maximal efforts. The climbs also were assumed to be relatively free of weather factors that could affect times. So usual reservations apply.

 

[More Strides than Rides]

Would you mind sharing the link here?

 

[TourOfTexas]

They make sense to me. What are we speculating about the nature of Froome's AEC doping?

 

[Race Radio]

4) Horner’s 2013 Vuelta CP was higher than that of any other rider in this study except Indurain in the height of the EPO era. His V02 max calculated from his CP was almost 90, and if not for a relatively low AEC, his numbers suggest he would blow Froome and just about anyone else out of the water.

Just an FYI, I wrote this months ago.....and was trolled with nonsense for weeks.

 

[Merckx index]

More Strides, the link is in my post, just click on the word "study".

Just an FYI, I wrote this months ago.....and was trolled with nonsense for weeks.

Haha, i was thinking of you when I wrote that, RR. Well, count me as one who has always been very suspicious of Horner. But again, it's his CP that is very high. His low AEC means that while his overall power is better than everyone else's on long climbs, it lags as the climbs become shorter. E.g., his overall power becomes about equal to Froome's at climbs of about 25-30 minutes, and for shorter climbs, Froome's is better. This is the advantage of having a higher AEC.

 

[the sceptic]

Just an FYI, I wrote this months ago.....and was trolled with nonsense for weeks.

this definitely proves you were right all along.

 

[Race Radio]

this definitely proves you were right all along.

....Thanks

 

[Saint Unix]

For me there are two questions that haven't been answered about Froome that are more important than any other:

1) How did he go from 47th overall in Tour de Suisse and 85th overall in Tour de Pologne to 2nd overall in the Vuelta in the space of less than three months in 2011? It's unlike anything anyone has ever done and it's not like his results beforehand showed any sign of him being able to pull off a podium finish in a Grand Tour.

2) How is he able to keep up with (or even beat) riders like Tony Martin, Cancellara and Phinney on flat time trials, while being skinny as a stick and not dedicating hours in a wind tunnel to perfect his position on the bike?


Those are the two things that will continue to baffle me more than anything else. I can't see how anyone can give a convincing answer to those two questions even if the math shows that his output is less than that of other GT winners.

 

[Big Doopie]

For me there are two questions that haven't been answered about Froome that are more important than any other:

1) How did he go from 47th overall in Tour de Suisse and 85th overall in Tour de Pologne to 2nd overall in the Vuelta in the space of less than three months in 2011? It's unlike anything anyone has ever done and it's not like his results beforehand showed any sign of him being able to pull off a podium finish in a Grand Tour.

2) How is he able to keep up with (or even beat) riders like Tony Martin, Cancellara and Phinney on flat time trials, while being skinny as a stick and not dedicating hours in a wind tunnel to perfect his position on the bike?


Those are the two things that will continue to baffle me more than anything else. I can't see how anyone can give a convincing answer to those two questions even if the math shows that his output is less than that of other GT winners.

Excellent questions.

The only way to explain froome is if you believe the following:

1. He is a natural athletic uber-talent on a level with Lemond.
2. That uber-talent remained hidden as long as he was affected by a parasite that specifically targeted his oxygen carrying ability -- something other riders were actually adding to with o2 vector doping.
3. (to a lesser degree of importance because it would have been gradual while his ascendency was not) the peloton became somewhat cleaner. Remember that even a clean uber-talent such as Lemond was completely destroyed by lesser riders on epo. So the only way froome is clean is if the general level of doping - particularly at the upper end -- is less pervasive or extreme than the early 90s.

So the only way I see someone believing froome is clean is if they believe all three above components of the narrative.

 

[ralphbert]

Personally I think the whole premise is rubbish. Just because you choose to sit in a group for tactical, weather or energy conservation reasons does not mean you are on your limit, in fact you cannot infur how much of there capacity they are using. Also from my own experience if you are climbing below your CP then you have extra capacity for over threshold efforts.

If froome dogs CP is not off the scale then why can he tt so well?

 

[Ripper]

A link to this study ...

Is this the same study that suggests Froome can hold 1228 watts for 2 minutes? I am not sure where they are getting these numbers, but that sounds pretty unbelievable.

The assumptions are off when it comes to deriving CP. All sorts of things impact one's capacity. Not that I am not suspicious of Horner, but to list Horner as very suspicious and Froome as clean as a whistle ... hmmmm

 

[Merckx index]

For me there are two questions that haven't been answered about Froome that are more important than any other:

1) How did he go from 47th overall in Tour de Suisse and 85th overall in Tour de Pologne to 2nd overall in the Vuelta in the space of less than three months in 2011? It's unlike anything anyone has ever done and it's not like his results beforehand showed any sign of him being able to pull off a podium finish in a Grand Tour.

Yes,as I pointed out in the OP, we need pre-2011 data for Froome. While his calculated CP may not be as high as that of other Tour winners, it would certainly suggest better performances than he had prior to the Vuelta.

2) How is he able to keep up with (or even beat) riders like Tony Martin, Cancellara and Phinney on flat time trials, while being skinny as a stick and not dedicating hours in a wind tunnel to perfect his position on the bike?

Froome is, I believe, 6'1" tall, which should make him naturally better at TTng than climbing. That is, he has an advantage over typical climbers who are usually shorter.

Of course his emaciated build ought to mean less power than riders of the same height and more normal build, but it also means less surface area. For two riders of the same height, with one skinnier than the other, surface area should increase linearly with mass, which increases by the square, rather than as the 2/3 power, as with riders of different heights. IOW, power vs. surface area should increase even more for riders of the same height as they increase in mass, as compared to riders of different height with the same body proportions.

E.g., if another rider the same height as Froome weighs 10% more, assuming the same distribution of weight, then that rider will have just 4.8% more surface area. So, yes, Froome's build should disadvantage him in TTng, relative to other riders of the same height.

In the 47 km ITT in the 2011 Vuelta, Froome finished about a minute behind Martin, and his SRM data indicated 406 watts, and a reported 5.8 w/kg. That is slightly higher than would be expected from the graph in the present study, but in the range.

OTOH, 5.8 watts/kg implies 70 kg body weight, I thought Froome was lighter than that. If he weighed 68 kg, that would be nearly 6.0 watt/kg, definitely an outlier on the curve which was emphasized as being unusually consistent. If we used that data point on a curve with the same slope (i.e., same AEC), Froome's CP would be 5.5, > AC in 2009 and almost as high as Horner's in the Vuelta.

Personally I think the whole premise is rubbish. Just because you choose to sit in a group for tactical, weather or energy conservation reasons does not mean you are on your limit, in fact you cannot infur how much of there capacity they are using. Also from my own experience if you are climbing below your CP then you have extra capacity for over threshold efforts.

The author does discuss those issues, and attempts to control for them.

Is this the same study that suggests Froome can hold 1228 watts for 2 minutes? I am not sure where they are getting these numbers, but that sounds pretty unbelievable.

The 1228 watts for two minutes is based I believe on extrapolation of the data from longer intervals, and that may not be valid for such short time periods. Horner’s estimated power for 2 minutes was only about 760 watts.

The assumptions are off when it comes to deriving CP. All sorts of things impact one's capacity.

Such as?

Interesting that the author did not mention Grappe’s analysis of Froome’s SRM data published last year. One of Grappe’s conclusions was that Froome’s V02max was one of the highest ever, but in the present study it was estimated at 81.5, lower than that of any of the other riders analyzed except Hesjedahl. This in fact is consistent with Froome being unusually tall for a climber, as taller riders generally have lower V02max/kg values than shorter riders.

OTOH, Grappe said Froome’s power curve was normal, with a loss of 60 watts from 20 to 60 minutes. That is very close to what the current study reported.

 

[Saint Unix]

Froome - 185cm, 69kg,on TT bike
Wiggins - 190cm, 69kg, on TT bike
Martin - 186cm, 75kg, on TT bike
Cancellara - 186cm, 82kg, on TT bike
Phinney - 197cm, 82kg, on TT bike

Those are height and weight values from the teams' websites. I'd assume they're correct, but I struggle to believe Froome and Wiggins weigh the same, and 69kg seems to be a bit too high for Froome anyway. I'm 180cm and I weight 70kg, and I'm far from a human skeleton like Froome. I've been up to 80kg at my heaviest. I bet I could drop down to 60kg and still look healthier than him.

Using eye measurement only the two Sky riders should be producing far less power than the other three, due to their incredibly skinny legs. Martin and Cancellara have thighs like tree trunks in comparison, yet Wiggins dominated the two TTs in the 2012 Tour and the Olympic TT in London a few weeks later and Froome has been able to out-TT Phinney and Cancellara on several occasions, while he has been close to Martin as well.

It's hard to make sense of it. As you said yourself, the heavier riders should produce more watts per unit of surface area. The pictures clearly show a huge difference in thigh and leg muscle as well.

I'd also like to mention the fact that the TT specialists are usually "nerds" when it comes to their performance against the clock. Brian Holm has said in interviews that Martin will work for hours and hours on improving even the smallest details to make him produce more power or reduce his surface area or weight, or even analyze every corner of a course to find the fastest line through. Cancellara is the same, as was Boardman and countless others. Compare that to Froome, who supposedly didn't even enter a wind tunnel until last year. I'm willing to bet that the difference in surface area between Cance/Panzerwagen and Froome isn't as big as their builds suggest.

Seeing as I can't understand how this is possible without a load of more or less improbable assumptions about Froome's talent and history up until 2011, I have to use Occam's Razor and assume the worst.

 

[EnacheV]

Thanks for a more elaborate confirmation of something i already believed.

 

[nomapnocompass]

Is this the same study that suggests Froome can hold 1228 watts for 2 minutes? I am not sure where they are getting these numbers, but that sounds pretty unbelievable.

The assumptions are off when it comes to deriving CP. All sorts of things impact one's capacity. Not that I am not suspicious of Horner, but to list Horner as very suspicious and Froome as clean as a whistle ... hmmmm

- It is the same paper, and it is indeed complete nonsense. The paper makes assumptions of the CP model that are known not to hold true, especially for performances <= 2mins.

 

[Ferminal]

The 1228 watts for two minutes is based I believe on extrapolation of the data from longer intervals, and that may not be valid for such short time periods. Horner’s estimated power for 2 minutes was only about 760 watts.

Isn't the whole thing an extrapolation of the data? That's how you get AWC v CP in the first place?

 

[nomapnocompass]

CP is a very limited model, for anaerobic efforts especially.

Extrapolating your 45 min FTP from a 20 min effort is valid, extrapolating your anaerobic capacity for efforts <= 2mins is most definitely not.

This paper is nonsense.

Veloclinic's take on it - http://tmblr.co/ZYh-gx1AH3taQ

 

[Alex Simmons/RST]

I haven't time to read it in detail at present, I just really quickly skimmed, but noticed some clearly incorrect statements in para 4.2 Determination of FTP.

 

[Dave_1]

Keep in mind Froome cracked bad at end of last mountain stage and his Ventoux and Alpe D'huez times were rubbish compared to most of the top dopers. Nothing suspicious about these times

Mont Ventoux


Fastest ever: 1. Iban Mayo 2004 (55:51) 2. Tyler Hamilton 2004 (56:26) 3. Jonathan Vaughters 1999 (56:50)
Fastest in 2013: 1. Chris Froome (59:00) 2. Nairo Quintana (59:29)

Alpe d'Huez

Fastest ever: 1. Marco Pantani 1995 (36:40) 2. Pantani 1997 (36:53) 3. Pantani 1994 (37:15)
Fastest in 2013: 1. Nairo Quintana (39:48) 2. Joaquim Rodriguez (39:51) 3. Richie Porte/Chris Froome (40:54)
Source: Climbing Record

 

[Saint Unix]

Keep in mind Froome cracked bad at end of last mountain stage and his Ventoux and Alpe D'huez times were rubbish compared to most of the top dopers. Nothing suspicious about these times

Mont Ventoux


Fastest ever: 1. Iban Mayo 2004 (55:51) 2. Tyler Hamilton 2004 (56:26) 3. Jonathan Vaughters 1999 (56:50)
Fastest in 2013: 1. Chris Froome (59:00) 2. Nairo Quintana (59:29)

You are aware of the fact that those record times were all set on time trials up Ventoux, right? Froome's time was set on a 240km stage. As for Alpe d'Huez, Froome never attacked because the GC was in the bag, and he ended up bonking near the top too. Had he gone hard like on Ax-3-Domaines or Ventoux that time would look very different. In other words, comparing times means nothing, because of all the variables.

 

[Dave_1]

You are aware of the fact that those record times were all set on time trials up Ventoux, right? Froome's time was set on a 240km stage. As for Alpe d'Huez, Froome never attacked because the GC was in the bag, and he ended up bonking near the top too. Had he gone hard like on Ax-3-Domaines or Ventoux that time would look very different. In other words, comparing times means nothing, because of all the variables.

You think I would come down into this snake pit without knowing that???Are you for real????????????????????

Marco Pantani, road stage 1994 TDF Mont Ventoux 57.54 on EPO!!!

 

[Dave_1]

if you compare Alpe D'huez TT times 2004 with road stages that finished up it, not much difference. Armstrong in 2001 and 2004 for example. Not huge differences. Those guys are fresh and warmed up with team towing them early on climb.

How was road surface on Ventoux in 1994 compared to 2014? Froome could not have handled Pantani's attacks even on Pantani's quite a bit heavier bike

 

[Saint Unix]

You think I would come down into this snake pit without knowing that???Are you for real????????????????????

Marco Pantani, road stage 1994 TDF Mont Ventoux 57.54 on EPO!!!

Calm down, bro.

 

[deviant]

Some of what i read in here is interesting and some of it is comical....a huge amount of stuff now comes across as sniping, gossipy, chit-chat with an undertone of wanting riders to get caught just so some members of the forum can say 'i told you so'....sad.

My thoughts on trying to second guess who is and isnt doping are best summed up by this review on Antoine Vayer's 'work'....

Some will argue that Vayer’s research is relevant, however, because it questions a few of the current crop of riders, including Christopher Froome, Andy Schleck, Bradley Wiggins, Alejandro Valverde, Alberto Contador, and Thomas Voeckler. But it’s these riders who are suffering the greatest injustice by this interminable fixation on the past. All of them, and everyone else in today’s peloton, are riding under the current rules and testing, and all continue to pass. (When they don’t, as with Valverde or Contador, they are subject to the disciplinary process.)

Enjoy the sport, given the money involved (in most major sports now) you're never going to get completely clean participants....the potential financial gain for winning is too great....but continual *****ing, inuendo and suspicion gets tiring.
The riders are tested and when they fail they get banned....it's a system i'm happy with.
Obviously some riders, either by themselves or with team involvement are always trying to get an edge either legally or illegally....i'm of the opinion that if it isnt against the rules yet then game on....be it new drug compounds, new bike technologies etc etc....if the UCI, WADA etc have a problem with it then they will ban it (whatever 'it' is?!) as they see fit.

Roll on 2014....there are some good riders showing good early season form and i look forward to some excellent races this year....as a side show it'll be interesting to see who gets pinged for doping this year....but this cant and should never be the main interest in cycling or any sport.

 

[More Strides than Rides]

More Strides, the link is in my post, just click on the word "study".

Ohh, duh. I'm reading this on my phone and missed it.

...

A lot has been pointed out already, but something that needs more emphasis is his pre '11 vuelta data. A big piece Of skepticism comes from his rise/jump to the world's best.

Data can be used to prove anything (peloton speeds are up/down/ sideways...). More complete data would be nice, but even that needs to be taken in in the context of his whole career and image by the very people who are unwilling to see the forest for the trees. An uphill fight for sure