The pedaling technique thread

[JamesCun]

Ugh, that data involves gross and delta efficiency which includes the drop in efficiency between the muscle and the wheel. Since the current discussion solely about the drop in efficiency between the muscle and the pedal it really doesn't add anything to the discussion. Whatever the starting point of the muscle efficiency the question I am trying to discuss here is how can we minimize the drop in efficiency between the muscle and the pedal to maximize the performance of the cyclist.

This study certainly removes a big part of your claim. If cyclists are 18-26% efficient (exactly the numbers stated in this study) they claim a significant portion of that difference is from muscle fibre ratios (from 30-70% type 1/2). They also explicitly state that pedal force testing shows now difference in pedalling technique contributed to the cycling economy differences seen.

So, a big part of your claim is explained in that study. You can't just change the question every time someone counters your assumptions.

 

[FrankDay]

This study certainly removes a big part of your claim. If cyclists are 18-26% efficient (exactly the numbers stated in this study) they claim a significant portion of that difference is from muscle fibre ratios (from 30-70% type 1/2). They also explicitly state that pedal force testing shows now difference in pedalling technique contributed to the cycling economy differences seen.

So, a big part of your claim is explained in that study. You can't just change the question every time someone counters your assumptions.

??? Which study?

 

[JamesCun]

??? Which study?

Pay attention. The study by Coyle that Sciguy posted and you responded to sciguy. The study that discusses exactly why different cyclists have significantly different cycling economy.

 

[FrankDay]

Pay attention. The study by Coyle that Sciguy posted and you responded to sciguy. The study that discusses exactly why different cyclists have significantly different cycling economy.

Unless that study claims that the contractile efficiency of the muscles was 16-26% then it doesn't address the issue being discussed here (losses between the muscle and pedal). It didn't. Clearly the efficiency of the muscle can have a dramatic influence on the overall cycling efficiency but the relationship was just highly correlated (R=.85) so it doesn't explain all of the difference. But, as I noted in my original response (which you apparently missed) they didn't address the issue we are currently discussing (or trying to discuss), the losses between the muscle and the pedal.

 

[JamesCun]

Unless that study claims that the contractile efficiency of the muscles was 16-26% then it doesn't address the issue being discussed here (losses between the muscle and pedal). It didn't. Clearly the efficiency of the muscle can have a dramatic influence on the overall cycling efficiency but the relationship was just highly correlated (R=.85) so it doesn't explain all of the difference. But, as I noted in my original response (which you apparently missed) they didn't address the issue we are currently discussing (or trying to discuss), the losses between the muscle and the pedal.

So they account for a significant portion of the variation seen between energy input and power output of different cyclists, but you don't think that translates to the losses seen at the pedal? Isn't the goal of improved pedal technique to improve economy? Do more work for the same energy input?

You'll have to explain why the study by Coyle doesn't directly account for a significant portion of that 16-26% economy that you are using as a key point to claim technique is a limiting factor in performance.

 

[JamesCun]

Edit: I might add this. Most cyclists have a gross cycling efficiency of 20%. A few pros have been measured at 26%. If the average cyclist could simply increase their efficiency from 20% to 26% they would see a 30% jump in power for the same energy expenditure. Understanding why these losses are there and how to correct them should be on every cyclists mind. It isn't.

If the difference between a 20% cyclist and 26% cyclist is primarily based on their fibre type composition, how do you propose changing that?

Can you cite examples of the 'pros' being at 26% vs that just being the high end of the measured cyclists? The study by Coyle has very well trained cyclists that have a range from 18 to 26%, independent of their level of 'pro'ness.

 

[coapman]

What we are trying to discuss here are the losses that occur between the muscle and the chain

Why did you change to discussing losses between the muscle and the pedal, there is a difference.

 

[sciguy]

If the difference between a 20% cyclist and 26% cyclist is primarily based on their fibre type composition, how do you propose changing that?

Can you cite examples of the 'pros' being at 26% vs that just being the high end of the measured cyclists? The study by Coyle has very well trained cyclists that have a range from 18 to 26%, independent of their level of 'pro'ness.

James,

Another really interesting study was carried out by Moseley, Acten, Martin and Jeukendrup back in 2004 where they found:
No differences in cycling efficiency between world-class and recreational cyclists.
http://www.ncbi.nlm.nih.gov/pubmed/15241718

The high level pros were no more efficient than everyday joe cyclists with very little experience and much lower levels of fitness. Quite a surprising result as one would expect better economy from those with many years of experience as well as success in racing. I'd love to see the GE and DE from a number of long term Powercranks and see how they stack up. If Frank's assertions are correct they all should have very high values since their techniques have been so well trained

Hugh

 

[JayKosta]

...
They also explicitly state that pedal force testing shows now difference in pedalling technique contributed to the cycling economy differences seen.
...

--------------------------------------
Would you please give some details about the 'pedaling technique' analysis and results that are contained in the 1992 Coyle article.

I haven't been able to download the full-text of the 1992 article, but there seems to be a 1994 article about the same study -

J F Horowitz, L. S. Sidossis and E. F Coyle,
High Efficiency of Type I Muscle Fibers Improves Performance.
Int. J. Sports Med., Vol. 15, No.3, pp. 152-157, 1994.

http://www.google.com/url?url=http:...sQFjAB&usg=AFQjCNHV7jwtnhHcFfQfzL1TGZRKhl1kow

And the 1994 article does not mention anything about having analyzed or considered 'pedaling technique' among the test subjects. So I'm curious about why that information about 'pedaling technique' was omitted in the 1994 version.

Jay Kosta
Endwell NY USA

 

[sciguy]

-
And the 1994 article does not mention anything about having analyzed or considered 'pedaling technique' among the test subjects. So I'm curious about why that information about 'pedaling technique' was omitted in the 1994 version.

Jay Kosta
Endwell NY USA

From the 10992 Coyle article.

Hope that helps.

Hugh

 

[JamesCun]

Google the title of the 1992 article and a full text PDF link will appear. They reference previous study that looked at pedal forces (frank disagrees with that study, but I think some would disagree with franks disagreement)

 

[JamesCun]

Seems like a study on the possible changes after a pedalling technique intervention would be easy to setup. Just find 10-20 cyclists/triathletes that have used powercranks consistently for at least 1 year and match them with cyclists who haven't done any power cranking. Test them, do some biopsies to match for fibre type and get the conclusive answer. Based on franks numbers, a PC rider should have a minimum economy of 25-35% (40% AVERAGE power improvement after PC immersion).

Interesting that he hasn't done that study yet. Would be hard to argue with if a cyclist had a GE/DE that was 10% higher than previously measured.

 

[FrankDay]

You'll have to explain why the study by Coyle doesn't directly account for a significant portion of that 16-26% economy that you are using as a key point to claim technique is a limiting factor in performance.

No I don't. We are only talking about the drop between the starting and ending point. What happens between the two is most likely independent of a finding that a higher starting point results in a higher ending point.

 

[FrankDay]

Why did you change to discussing losses between the muscle and the pedal, there is a difference.

Because I thought that "muscle and pedal" is technically a little more correct than "muscle and chain" even though the two are essentially identical. There will be some losses (due to hysteresis) in occurring in the crank arm and spider which are trivial in the materials used. If they were accurate enough the SRM power meter and the Vector power meter should measure slightly different values. They are not but there is a difference. What we are talking about here are the losses between the potential best muscle power output of the muscle and the power that is delivered to the pedals, where are the losses to account for the difference?

 

[FrankDay]

James,

Another really interesting study was carried out by Moseley, Acten, Martin and Jeukendrup back in 2004 where they found:
No differences in cycling efficiency between world-class and recreational cyclists.
http://www.ncbi.nlm.nih.gov/pubmed/15241718

The high level pros were no more efficient than everyday joe cyclists with very little experience and much lower levels of fitness. Quite a surprising result as one would expect better economy from those with many years of experience as well as success in racing.

Now you can understand my objection to the conclusion Coyle drew in the Armstrong paper (where he demonstrated a 10% increase in cycling efficiency during the time he was being tested). Coyle concluded that this demonstrated improvement in efficiency occurred because Armstrong had to change muscle fiber type because of training. No other explanation was entertained despite the fact that Armstrong was already a world champion when the first measurement was taken, such an improvement has never been shown in other pros who have trained similarly, no biopsies were taken, and it is known that Armstrong was working on improving his pedaling technique (specifically the weak back and top of his stroke) during this period.

I'd love to see the GE and DE from a number of long term Powercranks and see how they stack up. If Frank's assertions are correct they all should have very high values since their techniques have been so well trained

Yes, it would be interesting. Of course, it has not been done. Further, the test really requires testing before and after the study period begins (and, it would be nice to do muscle biopsy before and after so change in fiber type can also be evaluated as a possible explanation for any change seen). And, I am not sure how big of an improvement in efficiency I might expect. A 10% improvement surely should be expected (that was what was demonstrated by Luttrell) but what is the high end? Maybe 20% I would expect. 10% gets the 20% rider to 22% and the 20% improvement gets them to 24%. Whatever, the number is, any improvement is worth pursuing don't you think?

 

[FrankDay]

From the 10992 Coyle article.

Hope that helps.

Hugh

The problem is that most journals require authors that unless any difference reaches statistical significance they are "forced" to conclude that they can find no association. My guess is that most of these riders pedaled in reasonably similar fashion. Hence, any difference in efficiency due to technique would be small and it would be very difficult to demonstrate a statistically different efficiency from these subtle differences in technique.

 

[FrankDay]

Seems like a study on the possible changes after a pedalling technique intervention would be easy to setup. Just find 10-20 cyclists/triathletes that have used powercranks consistently for at least 1 year and match them with cyclists who haven't done any power cranking. Test them, do some biopsies to match for fibre type and get the conclusive answer. Based on franks numbers, a PC rider should have a minimum economy of 25-35% (40% AVERAGE power improvement after PC immersion).

Interesting that he hasn't done that study yet. Would be hard to argue with if a cyclist had a GE/DE that was 10% higher than previously measured.

I didn't have to do that study because someone else did it. Increase in GE of 10% in 6 weeks. http://www.ncbi.nlm.nih.gov/pubmed/14666944.

The Powercranks group had significantly higher GE values than the normal cranks group (23.6 +/- 1.3% versus 21.3 +/- 1.7%, and 23.9 +/- 1.4% versus 21.0 +/- 1.9% at 45 and 60 min, respectively), and significantly lower HR at 30, 45, and 60 minutes and VO2 at 45 and 60 minutes during the 1-hour submaximal ride posttraining.

Somehow though I think you are going to argue with that result. Let's see.

 

[JamesCun]

Well, they have done so without a single fact. To challenge the assumption that there are losses between the muscle and the pedal requires one to assume that the cyclist pedaling coordination and motion involves zero losses. To a mechanical engineer such a notion is ludicrous. This is especially evident when we know measured efficiency of cyclists varies between 16 and 26%. Unless one believes muscle contractile efficiency be vary that much. No one experienced in this area believes this.

You say 'especially evident' when efficiency varies between 16 and 26%. The Coyle study clearly suggests that muscle fibre type can account for a substantial portion of that cariance in efficiency.

Stop changing the goal posts when your claims are questioned.

 

[FrankDay]

You say 'especially evident' when efficiency varies between 16 and 26%. The Coyle study clearly suggests that muscle fibre type can account for a substantial portion of that cariance in efficiency.

Stop changing the goal posts when your claims are questioned.

Huh? I certainly do not object to the idea that different muscle fibers can result in different muscle efficiencies and this can affect overall efficiency. Coyle demonstrated that MOST of that variation can be explained by muscle fiber type. SO WHAT? We are trying to talk about the loss between the muscle and the pedal. I am afraid it is you who is trying to change the subject because you don't have anything to add to the question at hand but have a compulsion to object.

 

[sciguy]

Huh? I certainly do not object to the idea that different muscle fibers can result in different muscle efficiencies and this can affect overall efficiency. Coyle demonstrated that MOST of that variation can be explained by muscle fiber type. SO WHAT? We are trying to talk about the loss between the muscle and the pedal. I am afraid it is you who is trying to change the subject because you don't have anything to add to the question at hand but have a compulsion to object.

The SO WHAT is that you're the one who came out making a big deal in regards to how large the loss is when you really didn't seem to have any handle on it what so ever. Claiming a 50% loss makes the problem seem huge. It also emphasizes the importance of potential remediation if there was a way to do so. Marketers would call what you've done "creating a perceived need".

Hugh

 

[JamesCun]

The SO WHAT is that you're the one who came out making a big deal in regards to how large the loss is when you really didn't seem to have any handle on it what so ever. Claiming a 50% loss makes the problem seem huge. It also emphasizes the importance of potential remediation if there was a way to do so. Marketers would call what you've done "creating a perceived need".

Hugh

+1

Didn't think it would be so hard to get frank to see the point here. Apparently he needs everything connected with arrows and diagrams...maybe cartoons would be better???

 

[FrankDay]

The SO WHAT is that you're the one who came out making a big deal in regards to how large the loss is when you really didn't seem to have any handle on it what so ever. Claiming a 50% loss makes the problem seem huge. It also emphasizes the importance of potential remediation if there was a way to do so. Marketers would call what you've done "creating a perceived need".

Hugh

I am sorry. All I have asked is that we account for the entire loss. The fact that the wide variation can be "mostly" accounted for by a difference in muscle fiber type has nothing to do with the need to account for all of the losses. ACCOUNT FOR ALL OF THE LOSSES BETWEEN THE MUSCLE AND THE PEDAL, CHAIN, OR WHEEL. Since this is a pedaling technique thread it seems that we should be concentrating on either proving that pedaling technique causes zero losses or admitting that pedaling technique causes some of the losses seen and trying to quantify the size of the loss and discussing how much if any of this loss might be recoverable.

It is truly inconceivable, from a mechanical engineering perspective, that pedaling technique has no role in reducing overall cycling efficiency. Because this is a pedaling technique thread why don't we try to restrict ourselves to addressing this issue. My own thoughts on this subject is it is quite complicated and there are many different issues that add up to the whole. But, (some of) you guys won't even admit pedaling technique is an issue or there are losses after the muscle and before the pedal/chain.

 

[FrankDay]

+1

Didn't think it would be so hard to get frank to see the point here. Apparently he needs everything connected with arrows and diagrams...maybe cartoons would be better???

Yes. Let's see what you got here.

 

[JamesCun]

I am sorry. All I have asked is that we account for the entire loss. The fact that the wide variation can be "mostly" accounted for by a difference in muscle fiber type has nothing to do with the need to account for all of the losses. ACCOUNT FOR ALL OF THE LOSSES BETWEEN THE MUSCLE AND THE PEDAL, CHAIN, OR WHEEL. Since this is a pedaling technique thread it seems that we should be concentrating on either proving that pedaling technique causes zero losses or admitting that pedaling technique causes some of the losses seen and trying to quantify the size of the loss and discussing how much if any of this loss might be recoverable.

It is truly inconceivable, from a mechanical engineering perspective, that pedaling technique has no role in reducing overall cycling efficiency. Because this is a pedaling technique thread why don't we try to restrict ourselves to addressing this issue. My own thoughts on this subject is it is quite complicated and there are many different issues that add up to the whole. But, (some of) you guys won't even admit pedaling technique is an issue or there are losses after the muscle and before the pedal/chain.

So, are you going to stop using the variance in efficiency shown in the studies as evidence of pedalling technique having huge room for improvement? Pretty weak argument on your part if a key point you've made is so easily shown to be well accounted for in the research.

You are massively overstating the losses that might exist. Would you invest as much time if it is was a 1-2% change vs the 100% you claim theoretically possible?

Edit: You make a wild claim, based on an overly simplistic view of the situation and some faulty assumptions. Now, you turn around and yell at other people because we aren't doing the work to prove your claim. If you are so confident that technique has a possible improvement of 100%, go and prove it. Don't tell others that we have to prove it for you.

 

[coapman]

What we are talking about here are the losses between the potential best muscle power output of the muscle and the power that is delivered to the pedals, where are the losses to account for the difference?

How does one get an accurate value of the potential best muscle power output. There is a simple explanation for this power loss. As for the losses between pedal and chain, it's mainly due to the reduction in tangential effect of the force being applied between 1 and 5 o'c.