Froome's SRM data on Ventoux

[Merckx index]

Re: Re:

Ok, thanks! Not really sure I understand the last part though? What is the efficiency measured with respect to?

And isn't that a bit low? To have you lactic threshold at 85%of VO2max? Or how does this relate to heart rate? Is this equivalent to have your lactic threshold at 85% of max heart rate?

Let’s start with the relationship among V02max—how fast you can get oxygen into your body; LT—how fast you can do it at lactate threshold, when metabolic end products are piling up in your muscles; and efficiency—the amount of energy available, through metabolic processes constrained by the amount of oxygen taken in, that is converted to useful work, i.e., force on the pedals. Alex shows these relationships in the form of power curves at his blog:

http://alex-cycle.blogspot.com/2013/08/looking-under-hood.html

There are three graphs, for LTs of 80%, 85% and 90%. The higher the LT, the lower the other parameters can be to reach a particular power, such as 6.1 watts/kg. This power value is FTP, which is actually somewhat vague, but usually is understood as the power maintainable in a period of 40-60 minutes or so.

Let’s use the 85% LT curve. Why? A value of greater than 85% is quite rare, according to: http://journals.lww.com/acsm-essr/Citation/1982/01000/THE_ANAEROBIC_THRESHOLD_.3.aspx

Also, a study of trained athletes reported a mean of 79.2 +/- 1.7%, which indicates 85% is several SD above the mean: http://www.researchgate.net/profile/Kirk_Cureton/publication/19503418_Ratings_of_perceived_exertion_at_the_lactate_threshold_in_trained_and_untrained_men_and_women/links/0912f51136cc194efd000000.pdf

LT can be raised with training, of course, and one would expect higher values for elite athletes, but values above 85% are still not likely to be common. It’s worth noting that Coyle reported that LA’s was 75-85%.

At an LT of 85%, a rider needs very high values of V02max and efficiency to reach 6.1 watts/kg. The highest V02max values ever recorded are in the low to mid 90s, I believe. Let’s suppose Froome has a V02max of 92, which would put him among a handful of athletes on the planet. He would then need an efficiency of 22.5% to reach 6.1 watts/kg.

How common are efficiencies this high? Typical values lie in the range of 18-20%, with a SD of about 0.5%, and several studies have reported that there is no significant difference between competitive and recreational cyclists in this regard. So an efficiency of 22.5% is several SD above the mean, and probably found in less than 1% of the population. Moreover, it has also been reported that there is no correlation between V02max and efficiency, i.e., having an exceptionally high value of one of these parameters does not make one more likely to have an exceptionally high value of the other.

http://www.researchgate.net/profile/Asker_Jeukendrup/publication/12050999_The_reliability_of_cycling_efficiency/links/0fcfd50b07fb536556000000.pdf

http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.2005.101691/full

http://europepmc.org/abstract/med/8933490

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.469.3228&rep=rep1&type=pdf

I have seen a couple of studies reporting much higher efficiencies, in the mid to upper 20s. I don’t have the links for those right now. But AFAIK, they have not been replicated, and IIRC, there was actually evidence of a negative correlation with V02max, i.e., riders with very high efficiencies had lower than average (among their peers in the study) V02max.

So Froome would have to a V02 max that would make him one in several hundred million, if not one in a billion, coupled with an efficiency that would probably put him in a class of one in a hundred, if not even rarer. Even if you want to assume his LT is 90%, he would still need an efficiency of about 21.5%, which is well above average. If you assume his V02max is 90, which is still extraordinarily high, his efficiency needs to be 22%.

These are the kind of numbers that lead Tucker to be highly skeptical of Froome. Impossible? No. But quite unlikely, particularly--we most always add--because someone with such exceptional physiology should have shown better evidence of it when he was younger.

 

[ToreBear]

Ok I saw both the videos. I found them interesting and very educational. I would love to have readings on the guys he rode with. Anyway, I can't say my untrained eye saw anything fishy.

It would not surprise me if Froome is the leaker. I remember Froome saying he had no problem releasing data, it was Brailsford who was against it IIRC.

Froome is going to be accused of doping when he wins. Some will accuse him of doping after releasing his data. Froome will be cast in a suspicious light either way. So why not put it all out there?

Thats just a theory.

 

[acoggan]

Re: Re:

Ok, thanks! Not really sure I understand the last part though? What is the efficiency measured with respect to?

And isn't that a bit low? To have you lactic threshold at 85%of VO2max? Or how does this relate to heart rate? Is this equivalent to have your lactic threshold at 85% of max heart rate?

Let’s start with the relationship among V02max—how fast you can get oxygen into your body; LT—how fast you can do it at lactate threshold, when metabolic end products are piling up in your muscles; and efficiency—the amount of energy available, through metabolic processes constrained by the amount of oxygen taken in, that is converted to useful work, i.e., force on the pedals. Alex shows these relationships in the form of power curves at his blog:

http://alex-cycle.blogspot.com/2013/08/looking-under-hood.html

There are three graphs, for LTs of 80%, 85% and 90%. The higher the LT, the lower the other parameters can be to reach a particular power, such as 6.1 watts/kg. This power value is FTP, which is actually somewhat vague, but usually is understood as the power maintainable in a period of 40-60 minutes or so.

Let’s use the 85% LT curve. Why? A value of greater than 85% is quite rare, according to: http://journals.lww.com/acsm-essr/Citation/1982/01000/THE_ANAEROBIC_THRESHOLD_.3.aspx

Also, a study of trained athletes reported a mean of 79.2 +/- 1.7%, which indicates 85% is several SD above the mean: http://www.researchgate.net/profile/Kirk_Cureton/publication/19503418_Ratings_of_perceived_exertion_at_the_lactate_threshold_in_trained_and_untrained_men_and_women/links/0912f51136cc194efd000000.pdf

LT can be raised with training, of course, and one would expect higher values for elite athletes, but values above 85% are still not likely to be common. It’s worth noting that Coyle reported that LA’s was 75-85%.

For starters, you're confusing LT with the power that can be sustained for the duration of a typical long climb in a GT, e.g., 40-60 min.

For finishers, you're underestimating the frequency with which even LT can exceed 80% of VO2max in trained athletes.

To give you an example: the 7 NON-elite* cyclists in "group H" in this study had LTs (as defined as a 1 mmol/L increase in blood lactate above exercising baseline) that averaged 81.5% of VO2max, and were able to sustain 88.5% of VO2max for 60.8 min:

https://www.academia.edu/238318/Coyle_EF_Coggan_AR_Hopper_MK_Walters_TJ._Determinants_of_endurance_in_well-trained_cyclists._J_Appl_Physiol_1988_64_2622-2630

Coyle's 1991 paper in Med Sci Sports Exerc contains comparable data, except that the "national caliber" group in that study had even higher values (as you might expect).

*I was the most successful of all the subjects in that study, but while I made it up to cat. 1, never had any real success at a national level.

 

[Walkman]

Re: Re:

Ok, thanks! Not really sure I understand the last part though? What is the efficiency measured with respect to?

And isn't that a bit low? To have you lactic threshold at 85%of VO2max? Or how does this relate to heart rate? Is this equivalent to have your lactic threshold at 85% of max heart rate?

Let’s start with the relationship among V02max—how fast you can get oxygen into your body; LT—how fast you can do it at lactate threshold, when metabolic end products are piling up in your muscles; and efficiency—the amount of energy available, through metabolic processes constrained by the amount of oxygen taken in, that is converted to useful work, i.e., force on the pedals. Alex shows these relationships in the form of power curves at his blog:

http://alex-cycle.blogspot.com/2013/08/looking-under-hood.html

There are three graphs, for LTs of 80%, 85% and 90%. The higher the LT, the lower the other parameters can be to reach a particular power, such as 6.1 watts/kg. This power value is FTP, which is actually somewhat vague, but usually is understood as the power maintainable in a period of 40-60 minutes or so.

Let’s use the 85% LT curve. Why? A value of greater than 85% is quite rare, according to: http://journals.lww.com/acsm-essr/Citation/1982/01000/THE_ANAEROBIC_THRESHOLD_.3.aspx

Also, a study of trained athletes reported a mean of 79.2 +/- 1.7%, which indicates 85% is several SD above the mean: http://www.researchgate.net/profile/Kirk_Cureton/publication/19503418_Ratings_of_perceived_exertion_at_the_lactate_threshold_in_trained_and_untrained_men_and_women/links/0912f51136cc194efd000000.pdf

LT can be raised with training, of course, and one would expect higher values for elite athletes, but values above 85% are still not likely to be common. It’s worth noting that Coyle reported that LA’s was 75-85%.

At an LT of 85%, a rider needs very high values of V02max and efficiency to reach 6.1 watts/kg. The highest V02max values ever recorded are in the low to mid 90s, I believe. Let’s suppose Froome has a V02max of 92, which would put him among a handful of athletes on the planet. He would then need an efficiency of 22.5% to reach 6.1 watts/kg.

How common are efficiencies this high? Typical values lie in the range of 18-20%, with a SD of about 0.5%, and several studies have reported that there is no significant difference between competitive and recreational cyclists in this regard. So an efficiency of 22.5% is several SD above the mean, and probably found in less than 1% of the population. Moreover, it has also been reported that there is no correlation between V02max and efficiency, i.e., having an exceptionally high value of one of these parameters does not make one more likely to have an exceptionally high value of the other.

http://www.researchgate.net/profile/Asker_Jeukendrup/publication/12050999_The_reliability_of_cycling_efficiency/links/0fcfd50b07fb536556000000.pdf

http://onlinelibrary.wiley.com/doi/10.1113/jphysiol.2005.101691/full

http://europepmc.org/abstract/med/8933490

http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.469.3228&rep=rep1&type=pdf

I have seen a couple of studies reporting much higher efficiencies, in the mid to upper 20s. I don’t have the links for those right now. But AFAIK, they have not been replicated, and IIRC, there was actually evidence of a negative correlation with V02max, i.e., riders with very high efficiencies had lower than average (among their peers in the study) V02max.

So Froome would have to a V02 max that would make him one in several hundred million, if not one in a billion, coupled with an efficiency that would probably put him in a class of one in a hundred, if not even rarer. Even if you want to assume his LT is 90%, he would still need an efficiency of about 21.5%, which is well above average. If you assume his V02max is 90, which is still extraordinarily high, his efficiency needs to be 22%.

These are the kind of numbers that lead Tucker to be highly skeptical of Froome. Impossible? No. But quite unlikely, particularly--we most always add--because someone with such exceptional physiology should have shown better evidence of it when he was younger.

Wow, thanks for a great reply! I am reading at the moment, but I have one question that I think will help me to understand this a little bit better. When you talk about lactate threshold, what time period does that refer to?

Google gave me this:
"Lactate threshold is commonly known as the exercise intensity or blood lactate concentration at the one we can only sustain a high intensity effort for a specific period of time."

So, in cycling, how long is the time period we are taking about?

Like, for me, I can do around 30 minutes at 191 bpm with a max heart rate of 203 (laboratory tested). Would this level of intensity be my lactate threshold?

 

[acoggan]

Re: Re:

How common are efficiencies this high? Typical values lie in the range of 18-20%, with a SD of about 0.5%, and several studies have reported that there is no significant difference between competitive and recreational cyclists in this regard. So an efficiency of 22.5% is several SD above the mean, and probably found in less than 1% of the population.

Part II:

I also think that you are underestimating the efficiency of well-trained cyclists. Again using myself as an example: I have measured my own efficiency 12 different times at 6 different institutions using 4 different brands of metabolic carts and 4 different brands of cycle ergometer. At a power comparable to that generated by GT-winning pro cyclists, my efficiency averaged 23.6 +/- 1.2%.

 

[VO2 Max]

Yeah I think the problem here is that it's like looking at photo's of an animal's remains and trying to decide if it was a yeti: the information you have is incomplete and easily faked, and even if you do draw any conclusions from your evidence you've nothing to compare against because we're talking about the mythical clean Tour winner, which you don't know what it looks like and may have never even existed.

 

[Benotti69]

Pantani did not get skeletal like Froome...........

http://41.media.tumblr.com/862482c4bdb7205e0140f76a83357935/tumblr_nrj8xdkkju1qzrroto1_1280.jpg

 

[ScienceIsCool]

Re: Re:

How common are efficiencies this high? Typical values lie in the range of 18-20%, with a SD of about 0.5%, and several studies have reported that there is no significant difference between competitive and recreational cyclists in this regard. So an efficiency of 22.5% is several SD above the mean, and probably found in less than 1% of the population.

Part II:

I also think that you are underestimating the efficiency of well-trained cyclists. Again using myself as an example: I have measured my own efficiency 12 different times at 6 different institutions using 4 different brands of metabolic carts and 4 different brands of cycle ergometer. At a power comparable to that generated by GT-winning pro cyclists, my efficiency averaged 23.6 +/- 1.2%.

So at greater than 90% utilization and an efficiency of 23.6%, you must have had a VO2max below 70 or you'd have made pro for sure. Has anyone published a graph of the distribution of these parameters in the general population? That'd be a great for estimating the likelihood of generating a clean version of Froome.

Yes, I know that you believe that efficiency improves with training in pro-level athletes. Still doesn't make sense though because it assumes that there is no upper bound on efficiency. Either that or there is a confounding effect that caps efficiency even though it increases with training (i.e., it nose-dives during Christmas holidays).

John Swanson

 

[acoggan]

Re: Re:

So at greater than 90% utilization and an efficiency of 23.6%, you must have had a VO2max below 70 or you'd have made pro for sure.

You flatter me. In reality, my sustainable power was only 5-5.5 W/kg, which combined with being only 67-68 kg, no sprint, and racing criteriums in the flat midwest wasn't about to get me a pro contract, especially back in the late 1970s/early 1980s. That's why I decided to focus on school instead.

Has anyone published a graph of the distribution of these parameters in the general population?

You could probably find decent population data for VO2max (e.g., from military recruits), but not LT or efficiency.

 

[Benotti69]

Re: Re:

fhttp://www.cyclingnews.com/news/report-froome-to-undergo-independent-testing-to-try-to-prove-hes-clean

"I want the riders’ power data to be stored in a server - we’ve been discussing it with the ISSUL (Institute of Sports Science of the University of Lausanne). I'm ready to do it," said Grappe.

No good here, Grappe is apparently a Sky stooge, even though they didn't choose him to analyse Froome's data in 2013.

You do know that L'Equipe (owned by ASO) gave the data to Grappe. Grappe also cleared Armstorng of doping based on data..............

you're welcome

 

[ScienceIsCool]

Re: Re:

How common are efficiencies this high? Typical values lie in the range of 18-20%, with a SD of about 0.5%, and several studies have reported that there is no significant difference between competitive and recreational cyclists in this regard. So an efficiency of 22.5% is several SD above the mean, and probably found in less than 1% of the population.

Part II:

I also think that you are underestimating the efficiency of well-trained cyclists. Again using myself as an example: I have measured my own efficiency 12 different times at 6 different institutions using 4 different brands of metabolic carts and 4 different brands of cycle ergometer. At a power comparable to that generated by GT-winning pro cyclists, my efficiency averaged 23.6 +/- 1.2%.

So at greater than 90% utilization and an efficiency of 23.6%, you must have had a VO2max below 70 or you'd have made pro for sure. Has anyone published a graph of the distribution of these parameters in the general population? That'd be a great for estimating the likelihood of generating a clean version of Froome.

Yes, I know that you believe that efficiency improves with training in pro-level athletes. Still doesn't make sense though because it assumes that there is no upper bound on efficiency. Either that or there is a confounding effect that caps efficiency even though it increases with training (i.e., it nose-dives during Christmas holidays).

John Swanson

Which is totally in line with Lucia, Hoyas, et al: http://d3epuodzu3wuis.cloudfront.net/R063.pdf

There's a strong inverse relationship between economy (efficiency) and VO2max as measured for a dozen world-class cyclists. If you put your numbers on the graph (Figures 3 and 5) you'd be world-class if your VO2max was anywhere near 70. And this is at 80% utilization unless I misunderstood their methodology.

It also suggests that someone like Froome should be pretty darn rare since his data point so far off the trend-line that it would be hovering somewhere in the paragraph above the chart.

John Swanson

 

[zigmeister]

Well, let's bring up Wiggo into the conversation. He has recently said flat out, before his hour record attempt (I know, it is different, you don't ride 80-100 miles, then do a massive climb) but the point is, Wiggo claimed without even being trained he could do 410-415w for 1hr.

Thus, looking at Froome's supposed power numbers over those videos, besides some hard accelerations on attacks...there is nothing spectacular that anybody else isn't doing on that climb except for a few exceptions, and that is when he attacks. Then power drops down to 300w range as he recovers...then it picks back up shortly to the 400w range often.

What about Quintana on Monteaux climb? Yeah, Froome caught him, but Quintana was right there for a very long time taking pulls...must mean he is doped to the gills as well to do that initial attack on the group...

 

[ScienceIsCool]

Re:

Well, let's bring up Wiggo into the conversation. He has recently said flat out, before his hour record attempt (I know, it is different, you don't ride 80-100 miles, then do a massive climb) but the point is, Wiggo claimed without even being trained he could do 410-415w for 1hr.

Thus, looking at Froome's supposed power numbers over those videos, besides some hard accelerations on attacks...there is nothing spectacular that anybody else isn't doing on that climb except for a few exceptions, and that is when he attacks. Then power drops down to 300w range as he recovers...then it picks back up shortly to the 400w range often.

What about Quintana on Monteaux climb? Yeah, Froome caught him, but Quintana was right there for a very long time taking pulls...must mean he is doped to the gills as well to do that initial attack on the group...

Man, I really wish I had some links to videos of how *humans* used to race back in the 80's. The GTs back then were very, very different and no, it's not because of carbon fiber bikes.

John Swanson

 

[acoggan]

Re: Re:

There's a strong inverse relationship between economy (efficiency) and VO2max as measured for a dozen world-class cyclists.

I wouldn't consider an R2 of only 0.41 to be "strong".

That said, my own data* don't fall far from the regression line:

One thing to keep in mind, though, is that efficiency (and VO2max) were measured on an ergometer, whereas I'm basing my estimate of my sustainable power 30+ y ago based on, e.g., my TT performance, my CdA measured in more recent times but using comparable position and equipment, etc. IOW, lots of room for "slop" in the calculations (as is true in general for this topic).

*Using the average VO2max value from dozens of tests, but excluding those when I wasn't doing much training.

 

[Fearless Greg Lemond]

Re: Re:

Man, I really wish I had some links to videos of how *humans* used to race back in the 80's. The GTs back then were very, very different and no, it's not because of carbon fiber bikes.

John Swanson

https://www.youtube.com/watch?v=yqG_Hc0KF7A
A votre service.

 

[Benotti69]

Ross Tucker on radio about an hour ago

https://soundcloud.com/offtheball/ross-tucker-on-chris-fromme

 

[More Strides than Rides]

Re:

Well, let's bring up Wiggo into the conversation. He has recently said flat out, before his hour record attempt (I know, it is different, you don't ride 80-100 miles, then do a massive climb) but the point is, Wiggo claimed without even being trained he could do 410-415w for 1hr.

Thus, looking at Froome's supposed power numbers over those videos, besides some hard accelerations on attacks...there is nothing spectacular that anybody else isn't doing on that climb except for a few exceptions, and that is when he attacks. Then power drops down to 300w range as he recovers...then it picks back up shortly to the 400w range often.

What about Quintana on Monteaux climb? Yeah, Froome caught him, but Quintana was right there for a very long time taking pulls...must mean he is doped to the gills as well to do that initial attack on the group...

You put a few points together, so I hope I understood you...

Wiggans's performances are also highly suspect. Comparing Froome to Wiggans is not helpful if you're trying to say Froome is believable.

The fact that Froome can attack while sustaining that pace, and that he does so with such intensity is part of the suspicion of that climb. The "if you don't count the acceperations, it's not that impressive" is irrelevent, because there were accelerations, big ones.

Finally, yes, the other riders in the top group aren't defensible either. And Froome beat them all. Froome beat them without the natural talent that shows itself in young riding success and White Jersey's. He beat them without the naturally gifted VO2 max (anectdotally 80-85ish to Quintana's 90).

Explanations exist for outlier performances. But in Froome's case, his personal history conradicts all of the factors that could explain his performances. And the reasons substituted by him and Sky do not in any way add up to the performance level Froome brings day in and day out.

 

[Tonton]

Re: Re:

Longer than you seem to think, though. For example, back when I used a HR monitor I would average 94% of maximum during a typical 40 km TT. I would of course try to go "full gas" the final minute or two, but my HR would only rise a few beats/min.

Good point. I only used an HR monitor in my bikeless years, when training/running marathons. I would sustain 90%+ of my MHR during 40-45 minute hard tempo runs. However, tempo is the key word here. Brutal bursts like the two that Froome did seem quite different than a long sustained pace. Does it make sense? In a marathon for example (not a dope free sport), surges are not all-out sprints like in the video (BTW thanks Dear Wiggo!) but just an upping of the pace. Obviously you seem to know your stuff, even dueling with Merck Index (me I kiss his left shoe ). So?

 

[More Strides than Rides]

Re: Re:

Longer than you seem to think, though. For example, back when I used a HR monitor I would average 94% of maximum during a typical 40 km TT. I would of course try to go "full gas" the final minute or two, but my HR would only rise a few beats/min.

Good point. I only used an HR monitor in my bikeless years, when training/running marathons. I would sustain 90%+ of my MHR during 40-45 minute hard tempo runs. However, tempo is the key word here. Brutal bursts like the two that Froome did seem quite different than a long sustained pace. Does it make sense? In a marathon for example (not a dope free sport), surges are not all-out sprints like in the video (BTW thanks Dear Wiggo!) but just an upping of the pace. Obviously you seem to know your stuff, even dueling with Merck Index (me I kiss his left shoe ). So?

A different sport, but a few hueristic tests for runners, if you can't get in a lab: 800m race with a HR monitor will get you closest to your Max. If you have the equipment, which is now cheap and mobile, you can chart your lactate curve with 600m-recover-400m (both all out) session and then sampling at intervals for the next several minutes until you get your peak lactate. Pair that with data from 5-6x 800m progressing in pace, taking a sample after each interval. There are equations you can use to plug in the distance covered in a 12 minute run, weight, sex and height to get VO2 max. (Vertical leap is also a good indicator of elasticity, which is much more practical training data than any of those others...)

The point isn't the benifit/merits of the test, just giving an idea of what kind of effort matches different physiological extremes.

 

[Merckx index]

For starters, you're confusing LT with the power that can be sustained for the duration of a typical long climb in a GT, e.g., 40-60 min.

Yes, I did. Thanks for the correction. I don’t claim to be an expert in this field. Though in my defense, people who do claim to be frequently use the two terms interchangeably, which is why I didn’t know there was a distinction.

For finishers, you're underestimating the frequency with which even LT can exceed 80% of VO2max in trained athletes.

To give you an example: the 7 NON-elite* cyclists in "group H" in this study had LTs (as defined as a 1 mmol/L increase in blood lactate above exercising baseline) that averaged 81.5% of VO2max, and were able to sustain 88.5% of VO2max for 60.8 min

Well, the LT mean I quoted was close to 80, so I wasn’t underestimating the frequency with which it can exceed 80%. My point was that it doesn’t exceed 85% very often. And your own paper that you cite basically supports that, indicating 85% is about 2 SDs above the mean, at least for these non-elite cyclists (yes, 2/7 subjects were > 85%, but this was a small sample size; one subject does seem to be an outlier, though, if his values were excluded, the mean would be significantly higher).

The important issue, as JS noted, is the distribution of utilization. What % of elite riders are > 85%, and > 90%? It seems no one knows. Assuming >90% is rare, the arguments I provided against Froome still hold. If it isn’t rare, I guess I’d ask Alex why he didn’t post graphs with the parameter set at that value. Indeed, it seems all your subjects could maintain in the upper 80s for > 50 min., so what is the point of having a graph with the utilization parameter set at 80%?

I also think that you are underestimating the efficiency of well-trained cyclists. Again using myself as an example: I have measured my own efficiency 12 different times at 6 different institutions using 4 different brands of metabolic carts and 4 different brands of cycle ergometer. At a power comparable to that generated by GT-winning pro cyclists, my efficiency averaged 23.6 +/- 1.2%.

Based on the literature I’ve seen, I really think you are quite rare. Again, several studies have concluded that there’s no difference between trained and untrained cyclists. I won’t get into the claim that LA improved his efficiency with training.

I wouldn't consider an R2 of only 0.41 to be "strong".

But the point is that there is a negative correlation. Even a zero correlation would indicate it would be highly improbable that someone with a high V02max would also have a high efficiency. Any kind of negative correlation just decreases that already very low probability. E.g., the highest efficiency in that graph, 28%, is associated with a V02max of about 70. At 90% utilization, that would be about 6.1 watts/kg. So yes, if you had one of the highest efficiencies ever recorded, and presumably a very high utilization, you might make that standard. It's not impossible, but it's really on the outer edge.

Of course, the broader point is that we wouldn’t have to debate a lot of these things if the teams and riders would just release their data.

Finally, a point I think frequently overlooked by Froome supporters (I'm not accusing you, Andy, just responding to some other posters in this thread) is that you can't frame the debate in these terms: It's possible for Froome to put out this power clean vs. it's not possible for him to do it. Of course it might be possible for someone to do it, so as long as the debate is presented in that manner, Froome's supporters can claim it's possible he could.

But that is not the way the debate has to be framed. The real question is: what is the probability that Froome can put out this power clean vs. what is the probability that Froome is doping? As soon as one grasps this, the entire argument turns. Because compared to the tiny probabilities and outliers we are dealing with to explain his performance clean, the probability that any GC rider, including Froome, is doping is huge. Froome's saying he's clean does not change that probability. Froome's not testing positive doesn't change that probability significantly. Even if you want to argue the probability that Froome is doping is less than 50/50, it's still far greater than the probability of his putting out these numbers clean.

 

[Walkman]

Re: Re:

Back to the interesting storylines though, is his static heartrate during his attack. Whatever the number is, it should change. My intuition says that even thinking about attacking should change it. Unless there is a HR monitor machine calibration error, the only explanation is a motor.

I may have diluted my point: the lack of raise in HR is what struck me the most and what I can't understand.

One point I haven't seen mentioned by anyone else is the fact that heart rate monitors use noise-rejection algorithms to minimize artifacts due to, e.g., a PVC, the strap moving on the skin, etc. Those same algorithms also damp the response of the reported heart rate relative to actual changes.

That said, I suspect that the fact that his heart rate was already high relative to his own known low maximum had a lot to do with things.

But then if bpm couldn't go higher because he was so close to his MHR, he wouldn't have been able to sustain his effort the way he did. You can only go so long at 90% or more of your MHR.

Longer than you seem to think, though. For example, back when I used a HR monitor I would average 94% of maximum during a typical 40 km TT. I would of course try to go "full gas" the final minute or two, but my HR would only rise a few beats/min.

In my last two sessions I sustained around 94% of MHR (191 bmp with a max of 203) for around 30 minutes, but I have no trouble to increase the pace the last minute and reach MHR or very close to it, i.e. 200-203 bpm. I mean, why would you not be able to reach MHR when you are going "full gas" at the end?

 

[Benotti69]

https://www.youtube.com/watch?v=kbO_te8cv7c

Ventoux : Froome-2013 25secs better than Armstrong-Pantani 2000 -...

 

[Alex Simmons/RST]

Re: Re:

Keep in mind fatigue also lowers your HR. These are stage 15 or 9 where we get to see Froome's HR. It's going to be down ~5bpm at max effort from fatigue alone. Add in a lower MHR and this kind of thing is not unusual.

Max HR also falls with increasing fitness / as stroke volume increases.

And age

True 'dat.

 

[Alex Simmons/RST]

[quote="
So Strava does some post processing of the power meter data?
Generating a number akin to Normalized Power?

OK, I'm now thinking Dear Wiggo's alarm at the dodgy Strava numbers (in another thread I think) was well justified.

I was under the impression that data on Strava from a power meter was unadulterated.

As a GIS geek, Strava isn't accurate. At all. They make nice pictures and graphs and stats, but largely, it's all made up. Dodgy is the best word to describe Strava's output.

I'm commenting on Strava displays that use data uploaded from power meters, not power data estimated using mathematical methods and many loose assumptions.

 

[More Strides than Rides]

Re: Re:

In my last two sessions I sustained around 94% of MHR (191 bmp with a max of 203) for around 30 minutes, but I have no trouble to increase the pace the last minute and reach MHR or very close to it, i.e. 200-203 bpm. I mean, why would you not be able to reach MHR when you are going "full gas" at the end?

The 'full gas' you would need to give at the end may be full psychological gas (effort) but is usually not actually full gas due to muscle fiber failure/recruitment issues, energy storage,/shortage, built up byproducts of fatigue, the brain's/body's heat regulation and the fact that all of these keep your end spurt pretty short (relatively, too short to sustain increasing HR to max)