New study shows leg flexion less efficient than extension.

[King Boonen]

Re: Re:

But, changing how you move it means changing how you use your muscles, which is exactly what I said. So, what was your issue again? (edit: also, your original reply did not use the term relative - "Surely efficiency is just the metabolic cost to produce a certain amount of power?" - so it is not exactly what you said.)

Inserting the word relative, without stating what it's relative to makes no difference Frank.

LOL. Efficiency is expressed as a percentage. Determining a percentage requires a numerator and a denominator which, by definition, is a relationship between the two terms.

This statement has zero to do with what you have quoted.

 

[FrankDay]

Re: Re:

But, changing how you move it means changing how you use your muscles, which is exactly what I said. So, what was your issue again? (edit: also, your original reply did not use the term relative - "Surely efficiency is just the metabolic cost to produce a certain amount of power?" - so it is not exactly what you said.)

Inserting the word relative, without stating what it's relative to makes no difference Frank.

LOL. Efficiency is expressed as a percentage. Determining a percentage requires a numerator and a denominator which, by definition, is a relationship between the two terms.

This statement has zero to do with what you have quoted.

Huh? you said efficiency was "just the metabolic cost." What efficiency is is the ratio of the energy that gets to the wheel to the metabolic cost energy times 100. If we know the energy that gets to the wheel (the power) we can know the metabolic cost if we know the efficiency of the rider.

 

[FrankDay]

Re: Re:

Common sense is all that's required here, something that appears to be missing at that adult table where for almost a century they did not even realise that a narrower hand/arm position would improve performance in TT's, they probably required data before they would believe it. If that one legged rider had been asked during his first few pedal strokes after the fitting of the counterweight, where in his pedalling circle he felt most improvement, his answer would have confirmed it had nothing to do with mashing. His several years of one legged pedalling would still have an effect on his pedalling. Unlike the powercranker or circular pedaller who are using split concentration he can always give total concentration to his leg around the pedalling circle, resulting in a more powerful down stroke.

Wrong as we don't coach pedalling, we don't need to. People learn it rather quickly and research hasn't shown a better way. Those who make claims to be able to prove you can improve performance through different pedalling techniques have failed to provide any data. The OP study provides excellent data to show that mashing has a lower metabolic cost and greater efficiency than circular pedalling even after 7 years of immersion training in a circular style.

Just like all two legged cyclists who have a counterweight for each leg, there is nothing to prevent this one legged rider who has been fitted with a counterweight from using the basic circular style. The counterweight eliminates the one legged rider's added difficulty when taking the pedal from about 10 to 12 o'c which increases metabolic cost and reduces efficiency. How do you know he was using the mashing style ?

F Day can tell you the Powercranker's most difficult sector in the pedalling circle.

For the new PowerCranker the most difficult sector is usually coming over the top (from 9 to 12). For the well-trained PowerCranker there is no "most difficult" sector, i.e, all sectors should be of equal difficulty and that difficulty would depend upon how hard the rider is going because all of the muscles involved should be equally trained for the task they are being asked to perform.

 

[PhitBoy]

Re: New study shows leg flexion less efficient than extensio

I love these science denier threads! They remind me of "Merchants of Doubt". FD is particularly good at denial because he actually does understand at least some of the science and mixes accurate facts with propaganda. Very effective technique to manipulate the weak minded; essentially what conservative talk show hosts do. Just enough fact to confuse the fiction. Coapman/Backdoor/Perfection claims to have the most perfect pedaling technique on the face of the earth but has refused repeated invitations to have his technique analyzed at British Cycling in Manchester or at Brunel University in London. I would assume that means he doesn't want his fantastic pedaling technique exposed as fantasy.
Anyway, I believe the salient bits of the debate in this thread as well as the pedaling technique thread are:
1. Two studies in the peer reviewed literature have shown that cyclists are less efficient when they follow instructions to pull up more (Korff et al 2007 and Mornieux et al 2008)
2. Another paper shows that pedaling with one leg is less efficient that pedaling with two legs or than pedaling with a counterweight (Burns et a., 2014)
3. FD argues that these are acute interventions and those tested did not have the proper technique that they would get from prolonged training with decoupled cranks. Uncoupled cranks force the rider to pedal as if he was doing single leg cycling with no counterweight.
4. The study mentioned by the OP is a case study of a hip level amputee who has done nothing but single leg non counterweighted cycling for seven years. This should be very nearly the equivalent of long term training with decoupled powercranks. This four time US Paralympic National Champion was more efficient with a counterweight.
5. We know from the abstract by Elmer et al 2015 that cyclists pull up less when doing single leg pedaling with a counterweight (the full paper is in revision and should be accepted soon). Taken together these research findings strongly suggest that pulling up compromises efficiency even when the cyclist is well practiced.
I can't really follow FD's current argument about why this doesn't close the book on the notion of pulling up being more efficient.
So, CoachFergie, SciGuy, AndyCoggan, FD, and Coapman, thanks so much for the entertainment! Better than a reality show!
Yours Truly,
PhitBoy

 

[JayKosta]

Re: New study shows leg flexion less efficient than extensio

...
Taken together these research findings strongly suggest that pulling up compromises efficiency even when the cyclist is well practiced.
I can't really follow FD's current argument about why this doesn't close the book on the notion of pulling up being more efficient.
...

------------------------------
What conclusions have you reached (or read about) concerning the amount and effects of 'unweighting' done on the upstroke'. And do you think there is a difference between 'unweighting' and 'pulling-up'?

From what I've read, most 'higher category' competitive cyclists do quite a bit of unweighting on the upstroke - they are not intentionally using the alternate leg's power to lift or move the upstroke leg.

Jay Kosta
Endwell NY USA

 

[CoachFergie]

Re: New study shows leg flexion less efficient than extensio

...
Taken together these research findings strongly suggest that pulling up compromises efficiency even when the cyclist is well practiced.
I can't really follow FD's current argument about why this doesn't close the book on the notion of pulling up being more efficient.
...

------------------------------
What conclusions have you reached (or read about) concerning the amount and effects of 'unweighting' done on the upstroke'. And do you think there is a difference between 'unweighting' and 'pulling-up'?

From what I've read, most 'higher category' competitive cyclists do quite a bit of unweighting on the upstroke - they are not intentionally using the alternate leg's power to lift or move the upstroke leg.

You have read?

Cmon, present data, give references or it just looks like an opinion!!!

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

I love these science denier threads! They remind me of "Merchants of Doubt". FD is particularly good at denial because he actually does understand at least some of the science and mixes accurate facts with propaganda. Very effective technique to manipulate the weak minded; essentially what conservative talk show hosts do.

LOL. Clearly you don't consider yourself one of the "weak minded" who might fall for my manipulative arguments.

Just enough fact to confuse the fiction. Coapman/Backdoor/Perfection claims to have the most perfect pedaling technique on the face of the earth but has refused repeated invitations to have his technique analyzed at British Cycling in Manchester or at Brunel University in London. I would assume that means he doesn't want his fictional pedaling technique exposed as fantasy.

I agree.

Anyway, I believe the salient bits of the debate in this thread as well as the pedaling technique thread are:
1. Two studies in the peer reviewed literature have shown that cyclists are less efficient when they follow instructions to pull up more (Korff et al 2007 and Mornieux et al 2008)

If you look at those papers closely you will see that the subjects we not actually able to do what they were instructed to do. A problem with thinking about pedaling, the thought process is so slow that we lag behind where the foot is. edit: another thing happens with training. The character of the trained muscle changes to have less inefficient fast-twitch fibers and more efficient slower twitch fibers. Therefore, with training, efficiency of the muscle use should improve. Asking untrained muscles to do something and looking at efficiency masks the potential of what one might get if one were to train the muscles to do the task then look at efficiency.

2. Another paper shows that pedaling with one leg is less efficient that pedaling with two legs or than pedaling with a counterweight (Burns et a., 2014)

Do you have a link to this paper, I cannot find it. And, I presume, pedaling with a counterweight is less efficient than pedaling with two legs.

3. FD argues that these are acute interventions and those tested did not have the proper technique that they would get from prolonged training with decoupled cranks.

True. Training improves efficiency at whatever one is trying to do.

Uncoupled cranks force the rider to pedal as if he was doing single leg cycling with no counterweight.

No, you got that wrong. Probably because you don't understand what uncoupled cranks require of the rider. Uncoupled cranks riding is exactly in between the two one legged conditions. It is like counterbalanced one-legged pedaling on the upstroke and uncounterbalanced one-legged pedaling on the downstroke. Neither experimmental condition replicates uncoupled pedaling.

4. The study mentioned by the OP is a case study of a hip level amputee who has done nothing but single leg non counterweighted cycling for seven years. This should be very nearly the equivalent of long term training with decoupled powercranks. This four time US Paralympic National Champion was more efficient with a counterweight.

Nope. As I said, it is not the eqivalent. Anyone who says it is has never ridden the cranks and doesn't understand what they require. You are guessing when you say that.

5. We know from the abstract by Elmer et al 2015 that cyclists pull up less when doing single leg pedaling with a counterweight (the full paper is in revision and should be accepted soon). Taken together these research findings strongly suggest that pulling up compromises efficiency even when the cyclist is well practiced.
I can't really follow FD's current argument about why this doesn't close the book on the notion of pulling up being more efficient.

WE don't know anything until the paper is available to us but I will accept that as true based upon the thought experiment and what I know of uncoupled pedaling (which is similar to counterbalanced one-legged pedaling ON THE UPSTROKE ONLY. The problem is counter-balanced one-legged pedaling makes the rider push harder than they do in two legged pedaling (or when riding uncoupled cranks) because there is no unweighting on the opposite side when pushing.

So, CoachFergie, SciGuy, AndyCoggan, FD, and Coapman, thanks so much for the entertainment! Better than a reality show!
Yours Truly,
PhitBoy

Thanks for at least reading the arguments seriously even if you missed some of the nuances.

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

...
Taken together these research findings strongly suggest that pulling up compromises efficiency even when the cyclist is well practiced.
I can't really follow FD's current argument about why this doesn't close the book on the notion of pulling up being more efficient.
...

------------------------------
What conclusions have you reached (or read about) concerning the amount and effects of 'unweighting' done on the upstroke'. And do you think there is a difference between 'unweighting' and 'pulling-up'?

From what I've read, most 'higher category' competitive cyclists do quite a bit of unweighting on the upstroke - they are not intentionally using the alternate leg's power to lift or move the upstroke leg.

You have read?

Cmon, present data, give references or it just looks like an opinion!!!

Do you have any data to suggest his "reading" of the literature is wrong? Come on, present data, give references, or it just looks like an opinion! (or being a jerk).

 

[CoachFergie]

Re: New study shows leg flexion less efficient than extensio

I love these science denier threads! They remind me of "Merchants of Doubt". FD is particularly good at denial because he actually does understand at least some of the science and mixes accurate facts with propaganda. Very effective technique to manipulate the weak minded; essentially what conservative talk show hosts do. Just enough fact to confuse the fiction. Coapman/Backdoor/Perfection claims to have the most perfect pedaling technique on the face of the earth but has refused repeated invitations to have his technique analyzed at British Cycling in Manchester or at Brunel University in London. I would assume that means he doesn't want his fantastic pedaling technique exposed as fantasy.
Anyway, I believe the salient bits of the debate in this thread as well as the pedaling technique thread are:
1. Two studies in the peer reviewed literature have shown that cyclists are less efficient when they follow instructions to pull up more (Korff et al 2007 and Mornieux et al 2008)
2. Another paper shows that pedaling with one leg is less efficient that pedaling with two legs or than pedaling with a counterweight (Burns et a., 2014)
3. FD argues that these are acute interventions and those tested did not have the proper technique that they would get from prolonged training with decoupled cranks. Uncoupled cranks force the rider to pedal as if he was doing single leg cycling with no counterweight.
4. The study mentioned by the OP is a case study of a hip level amputee who has done nothing but single leg non counterweighted cycling for seven years. This should be very nearly the equivalent of long term training with decoupled powercranks. This four time US Paralympic National Champion was more efficient with a counterweight.
5. We know from the abstract by Elmer et al 2015 that cyclists pull up less when doing single leg pedaling with a counterweight (the full paper is in revision and should be accepted soon). Taken together these research findings strongly suggest that pulling up compromises efficiency even when the cyclist is well practiced.
I can't really follow FD's current argument about why this doesn't close the book on the notion of pulling up being more efficient.
So, CoachFergie, SciGuy, AndyCoggan, FD, and Coapman, thanks so much for the entertainment! Better than a reality show!
Yours Truly,
PhitBoy

Well posted, look forward to seeing the full Elmer paper. You understand and sum up the state of play nicely!

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

Anyway, I believe the salient bits of the debate in this thread as well as the pedaling technique thread are:
1. Two studies in the peer reviewed literature have shown that cyclists are less efficient when they follow instructions to pull up more (Korff et al 2007 and Mornieux et al 2008)

Here is a paper you might be interested in: Altered muscle coordination when pedaling with independent cranks
François Hug, Florian Boumier, and Sylvain Dorel http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3755179/
From the paper

In addition to these alterations of muscle activity level, cycling with independent cranks altered the functional role of some muscles. Inspection of both the muscle activation profiles (Figure ​(Figure2)2) and activation amplitude per sector (Figure ​(Figure4)4) confirmed our hypothesis that hamstrings which are normally active at the end of the downstroke phase, were also active through the entire upstroke phase when cycling with independent cranks. This is in contrast to a study from Mornieux et al. (2010), who reported no change in the timing of BF activity when the subjects were instructed to actively pull-up on the pedal while they used normal cranks. Consequently, instructing the participants to actively pull-up on the pedal is unlikely to reproduce the effects induced by the use of independent cranks.

Or, from the end of the paper

Interestingly, the present study showed variability in the way the participants adapted to new mechanical constraints. Hence, it is possible that the gain in pedaling technique (if any) related to the long-term use of independent cranks differs between individuals as well. This might explain the failure of previous studies to show any systematic effect of training with independent cranks either in muscle coordination, or gross efficiency (Burns et al., 2012). In other words, long-term benefits might depend on the coordination strategy adopted when cycling with uncoupled cranks, thus raising questions about the relevance of the use of a learning period prior using independent cranks within a training program.

Unless a study actually looks at the coordination changes that occur during training with uncoupled cranks then one is forced to guess as to what coordination changes did or did not occur when trying to reach conclusions as to whether the intervention was adequate to investigate the idea. Are the positive benefits shown by Dixon and Luttrell from training with PowerCranks due to coordination changes or something else? We don't know because technique wasn't measured. Are the failures to show benefit in other studies (Burns and others) because of a failure to adequately change the coordination or despite a change in coordination. We don't know because technique wasn't measured. The science in this area is abysmal. I have my bias based on lots of experience with the product. Most of the other side experience with the product is, well, nil but they still have a bias. Everyone is arguing their bias. The question is what is the basis of the bias. It sure isn't science, despite Fergies protestations to the contrary.

 

[JayKosta]

Re: New study shows leg flexion less efficient than extensio

------------------------------
What conclusions have you reached (or read about) concerning the amount and effects of 'unweighting' done on the upstroke'. And do you think there is a difference between 'unweighting' and 'pulling-up'?

From what I've read, most 'higher category' competitive cyclists do quite a bit of unweighting on the upstroke - they are not intentionally using the alternate leg's power to lift or move the upstroke leg.

You have read?

Cmon, present data, give references or it just looks like an opinion!!!

----------------------------------------------------------------------
A primary source of info for me is Coyle's
Physiological and biomechanical factors associated with elite endurance cycling performance
0195-9131/91/2301-0093$3.00/0
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
Copyright@ 1991 by the American College of Sports Medicine

particularly Figs 4, 5, and 7

Also, Steven A. Kautz and Richard R. Neptune
Biomechanical Determinants of Pedaling Energetics: Internal and External Work Are Not Independent
Exercise and Sport Sciences Reviews Volume 30
Number 4
October 2002

particularly Figure 3

I am interested in your analysis of those articles (or other articles that measure 'power data' at several segments around the crank rotation).
Do you see indications that significant 'unweighting on the upstroke' is not being done?
Any indications that significant 'pulling up beyond unweighting' is being done?

Jay Kosta
Endwell NY USA

 

[backdoor]

Re: New study shows leg flexion less efficient than extensio

------------------------------
What conclusions have you reached (or read about) concerning the amount and effects of 'unweighting' done on the upstroke'. And do you think there is a difference between 'unweighting' and 'pulling-up'?

From what I've read, most 'higher category' competitive cyclists do quite a bit of unweighting on the upstroke - they are not intentionally using the alternate leg's power to lift or move the upstroke leg.

You have read?

Cmon, present data, give references or it just looks like an opinion!!!

----------------------------------------------------------------------
A primary source of info for me is Coyle's
Physiological and biomechanical factors associated with elite endurance cycling performance
0195-9131/91/2301-0093$3.00/0
MEDICINE AND SCIENCE IN SPORTS AND EXERCISE
Copyright@ 1991 by the American College of Sports Medicine

particularly Figs 4, 5, and 7

Also, Steven A. Kautz and Richard R. Neptune
Biomechanical Determinants of Pedaling Energetics: Internal and External Work Are Not Independent
Exercise and Sport Sciences Reviews Volume 30
Number 4
October 2002

particularly Figure 3

I am interested in your analysis of those articles (or other articles that measure 'power data' at several segments around the crank rotation).
Do you see indications that significant 'unweighting on the upstroke' is not being done?
Any indications that significant 'pulling up beyond unweighting' is being done?

Jay Kosta
Endwell NY USA

When you unweight the rising pedal where does that weight go ?

 

[CoachFergie]

Again you guys try to make mountains out of molehills. The sum of the parts is never greater than the whole. From Korff, Barrett and Gardner (2012), Pedalling mechanics and performance optimisation, in Performance Cycling: The Science of Success, edited by Hopker and Jobson (Simon Jobson chaired the session where I spoke on my research in Leeds last year) present data that most interventions designed to change submaximal pedalling mechanics do not result in improvements in efficiency. Frank will say Luttrell but all subsequent studies failed to find an improvement in efficiency which casts don't on the data presented by Luttrell.

Still inescapable that the OP showed that a rider with seven years of immersion training in a circular style of pedalling lowered metabolic cost and improved efficiency by changing to a counter weighted other pedal which allowed him to pedal in a mashing style. Comment in the scientific community is that this is a smoking gun that shows that Frank's many, all unproven, claims are worthless.

 

[JayKosta]

Re: New study shows leg flexion less efficient than extensio

...
When you unweight the rising pedal where does that weight go ?

---------------------------------
The 'common usage' definition of 'unweighting on the upstroke' is that the foot continues to be moved by active muscle force in a circular motion so that it doesn't impart any positive or negative force to the pedal.
The primary goal of unweighting is to allow the full force of the downstroke to produce 'power to the chain', and not to have any of the downstroke force be used to mechanically move the upstroke foot and leg.

So 'where does the weight go?' - it goes to the downstroke to produce more 'chain power'.

Basically that means that the speed and direction of the foot on the upstroke is synchronized with the alternate foot doing the downstroke. And before you say that this require two separate mental concentrations, try moving both of your hand/arms in circular motion at the same time - it requires much more mental effort to NOT be in sync. Our bilateral use of arms and legs makes it easy to coordinate both sides at the same time.
It is just a matter of 'how well' certain people do that coordination. Some people can do it very well with very little training, and other people can benefit from training to improve their coordination.

Jay Kosta
Endwell NY USA

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

...
When you unweight the rising pedal where does that weight go ?

---------------------------------
The 'common usage' definition of 'unweighting on the upstroke' is that the foot continues to be moved by active muscle force in a circular motion so that it doesn't impart any positive or negative force to the pedal.
The primary goal of unweighting is to allow the full force of the downstroke to produce 'power to the chain', and not to have any of the downstroke force be used to mechanically move the upstroke foot and leg.

So 'where does the weight go?' - it goes to the downstroke to produce more 'chain power'.

Basically that means that the speed and direction of the foot on the upstroke is synchronized with the alternate foot doing the downstroke. And before you say that this require two separate mental concentrations, try moving both of your hand/arms in circular motion at the same time - it requires much more mental effort to NOT be in sync. Our bilateral use of arms and legs makes it easy to coordinate both sides at the same time.
It is just a matter of 'how well' certain people do that coordination. Some people can do it very well with very little training, and other people can benefit from training to improve their coordination.

Jay Kosta
Endwell NY USA

That is a very nice explanation of the concept. I was struggling to figure out what to say here.

I might add that the Kautz and Neptune article you referenced has something to say about this.

Previous work has partially refuted this misconception by showing that more muscular effort would be required to eliminate the negative torque (counter-torque) during the upstroke than would be required to pedal normally with a counter-torque (13). Note that the counter-torque represents work done on the upstroke leg, not necessarily that the leg is pushing down. In fact, during the upstroke muscles do significant positive work (e.g., Fig. 4, all other muscles) and little negative work. Most of this negative work would still exist even if counter-torque were eliminated by other concentric muscles (e.g., hip flexors) because it is associated with the deactivation of muscles such as VAS (Fig. 4). Because little dissipation of energy by negative muscle work occurs, the work associated with the counter-torque results in increased energy of the leg as the potential and kinetic energies increase as the leg is pushed upwards (Fig. 2B and 2D).

The question is not whether these "upstroke" muscles can do work to drive the bicycle because they are doing so now (despite the negative forces on the pedals everyone sees). The real question is whether they can do more work than they currently are doing and what is the optimum amount of work for them to do compared to the "pushing" muscles.

 

[PhitBoy]

Re: New study shows leg flexion less efficient than extensio

Hi Jay:
I can see you've thought about his a bit. Well done.
In all the data I've seen, muscular power (the sum of ankle, knee, hip, and hip transfer power) is positive during almost of all the leg flexion phase. Most of that power comes from knee flexion (hamstrings and gastroc). The power during submaximal cycling is not as great as the power required to lift the leg so negative power is still observed at the pedal (gasp!). This would be in the category that I think you would call "unweighting".
With increases in power (e.g. 250, 400, 550, 700, 850 (submax!), and maximal sprint; see Elmer et al. 2011 in MSSE) absolute power for each joint action increases and power during flexion will eventually be positive even at the pedal level meaning that power during flexion is greater than that required to lift the leg.
This data is highly relevant to the discussion of pedaling technique and motor skill acquisition because it shows that all the cyclists we have tested (from recreational to elite) CAN pull up enough to produce positive pedal power during flexion but they CHOOSE not too do so when pedaling at endurance level powers. Repeat, everyone already knows how to pull up with power. They don't need split cranks or drills to learn how. Why do they choose not to pull up more? I don't know for sure but one explanation would be because their perceptual feedback tells them its less efficient to do so as all studies have shown.
PhitBoy

I am interested in your analysis of those articles (or other articles that measure 'power data' at several segments around the crank rotation).
Do you see indications that significant 'unweighting on the upstroke' is not being done?
Any indications that significant 'pulling up beyond unweighting' is being done?
Jay Kosta
Endwell NY USA

 

[backdoor]

Re: New study shows leg flexion less efficient than extensio

...
When you unweight the rising pedal where does that weight go ?

---------------------------------
The 'common usage' definition of 'unweighting on the upstroke' is that the foot continues to be moved by active muscle force in a circular motion so that it doesn't impart any positive or negative force to the pedal.
The primary goal of unweighting is to allow the full force of the downstroke to produce 'power to the chain', and not to have any of the downstroke force be used to mechanically move the upstroke foot and leg.

So 'where does the weight go?' - it goes to the downstroke to produce more 'chain power'.

Basically that means that the speed and direction of the foot on the upstroke is synchronized with the alternate foot doing the downstroke. And before you say that this require two separate mental concentrations, try moving both of your hand/arms in circular motion at the same time - it requires much more mental effort to NOT be in sync. Our bilateral use of arms and legs makes it easy to coordinate both sides at the same time.
It is just a matter of 'how well' certain people do that coordination. Some people can do it very well with very little training, and other people can benefit from training to improve their coordination.

Jay Kosta
Endwell NY USA

I already knew the answer but I wanted to know if people knew there could be a double advantage to the correct unweighting technique. The down foot does not have to push the idling leg up and part of the weight of that idling leg is added to down stroke power. While unweighting will not interfere with total concentration on power application, pulling up will not only split it in two and give a weaker down stroke, it will also transfer the weight of the idling leg to the saddle, which is why so many PC'ers have a sore ass.

 

[backdoor]

Re:

Again you guys try to make mountains out of molehills. The sum of the parts is never greater than the whole. From Korff, Barrett and Gardner (2012), Pedalling mechanics and performance optimisation, in Performance Cycling: The Science of Success, edited by Hopker and Jobson (Simon Jobson chaired the session where I spoke on my research in Leeds last year) present data that most interventions designed to change submaximal pedalling mechanics do not result in improvements in efficiency. Frank will say Luttrell but all subsequent studies failed to find an improvement in efficiency which casts don't on the data presented by Luttrell.

Still inescapable that the OP showed that a rider with seven years of immersion training in a circular style of pedalling lowered metabolic cost and improved efficiency by changing to a counter weighted other pedal which allowed him to pedal in a mashing style. Comment in the scientific community is that this is a smoking gun that shows that Frank's many, all unproven, claims are worthless.

Why do all the pedalling researches have to concentrate on negative research, why not go out and do something positive that would change your views on the importance of technique. The fact is TDC can be replaced with maximal torque but for as long as they believe that this is impossible they will never discover how it can be done. Why do you have to be a one trick pony, if you took time to learn both techniques, you would know how to relax your mashing muscles during the less stressful times in road races. Again I ask, how do you know this one legged rider used the mashing style when using the counterweight..

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

Hi Jay:
I can see you've thought about his a bit. Well done.
In all the data I've seen, muscular power (the sum of ankle, knee, hip, and hip transfer power) is positive during almost of all the leg flexion phase. Most of that power comes from knee flexion (hamstrings and gastroc). The power during submaximal cycling is not as great as the power required to lift the leg so negative power is still observed at the pedal (gasp!). This would be in the category that I think you would call "unweighting".
With increases in power (e.g. 250, 400, 550, 700, 850 (submax!), and maximal sprint; see Elmer et al. 2011 in MSSE) absolute power for each joint action increases and power during flexion will eventually be positive even at the pedal level meaning that power during flexion is greater than that required to lift the leg.

Wow, there is an insight worth repeating. Regardless of how one pedals, when one increases effort they increase the effort of all the muscles involved in pedaling and not just pushing harder. We all "naturally" distribute the work of pedaling around the entire circle. Everyone "pulls up" on the backstroke the only difference between these different techniques is in the degree with which they pull up. In the OP this study showed that pulling up way more than pushing down was less effective than pushing much harder than pulling. But, both of these unbalanced methods of pedaling resulted in lower efficiency than the historically accepted normal pedaling efficiency where work is more balanced. The question is what is the optimum amount of "pulling up" (or work distribution)? My own belief is that better work balance (distribution) results in improved efficiency and increased power potential.

This data is highly relevant to the discussion of pedaling technique and motor skill acquisition because it shows that all the cyclists we have tested (from recreational to elite) CAN pull up enough to produce positive pedal power during flexion but they CHOOSE not too do so when pedaling at endurance level powers. Repeat, everyone already knows how to pull up with power. They don't need split cranks or drills to learn how. Why do they choose not to pull up more? I don't know for sure but one explanation would be because their perceptual feedback tells them its less efficient to do so

Well, that is one explanation. But there are others. I think the most pertinent question to ask is can we explain why we pedal this way? Is there an explanation that goes beyond this being the optimum way? And, low and behold, there is. It goes to how we ALL LEARNED to pedal on platform pedals. Platform pedals require the rider to hold back, beyond the capability of the muscles, on the upstroke and over the top to keep contact with the pedal. This pattern gets ingrained in the unconscious coordination during our formative years and then is very difficult to undo. Getting attached to the pedals only means you can undo it, not that it happens automatically. That is the whole purpose of uncoupled cranks, to undo this ingrained pattern to see if there is any difference. I explain this in more detail in the first part of this video. http://youtu.be/1KR5OO7AJcI There are actually some studies to support this notion (see below)

as all studies have shown.
PhitBoy

Not quite. You forget Luttrell where cycling efficiency improved 10% (20-22%) after a period of training on PowerCranks. And, Leirdahl, where efficiency correlated with dead space effort. One cannot have a good effort over the top without also have an good effort from 9 to 12. Also, the study by Coyle showing Armstrong's efficiency improved 10% over a period of years during which he was working on improving what he did on the backstroke and over the top (per a Carmichael Training systems post). Neither Luttrell or Coyle measured technique but the stated goal of the two efforts was to improve this area of the stroke and the results speak for themselves.

 

[CoachFergie]

Re: Re:

Again you guys try to make mountains out of molehills. The sum of the parts is never greater than the whole. From Korff, Barrett and Gardner (2012), Pedalling mechanics and performance optimisation, in Performance Cycling: The Science of Success, edited by Hopker and Jobson (Simon Jobson chaired the session where I spoke on my research in Leeds last year) present data that most interventions designed to change submaximal pedalling mechanics do not result in improvements in efficiency. Frank will say Luttrell but all subsequent studies failed to find an improvement in efficiency which casts don't on the data presented by Luttrell.

Still inescapable that the OP showed that a rider with seven years of immersion training in a circular style of pedalling lowered metabolic cost and improved efficiency by changing to a counter weighted other pedal which allowed him to pedal in a mashing style. Comment in the scientific community is that this is a smoking gun that shows that Frank's many, all unproven, claims are worthless.

Why do all the pedalling researches have to concentrate on negative research, why not go out and do something positive that would change your views on the importance of technique. The fact is TDC can be replaced with maximal torque but for as long as they believe that this is impossible they will never discover how it can be done. Why do you have to be a one trick pony, if you took time to learn both techniques, you would know how to relax your mashing muscles during the less stressful times in road races. Again I ask, how do you know this one legged rider used the mashing style when using the counterweight..

Because no one, you and Frank in particular, have made a valid argument and provided any data to suggest I should pay any attention to pedalling beyond appropriate cadence and positioning of the saddle and foot on the pedal. Anything else is a waste of time like Frank dicking around with crank length. Nothing in the data to support it.

Imagination (you) and made up data or charts (Frank) are pathetic in an argument with people who do actual research.

 

[CoachFergie]

http://wattagetraining.com/files/JMartinCrankLengthPedalingTechnique.pdf

Still sums most of this nonsense from some with delusions or a product to sell (and some delusions) or a narrow view of what is, and is not important to cycling performance!

Also suggests the OP should read "study adds to the literature showing that leg flexion is less efficient than leg extension in cycling"!

 

[berend]

Re: Re:

Why do all the pedalling researches have to concentrate on negative research, why not go out and do something positive that would change your views on the importance of technique.

The pedalling researchers do concentrate on positive research: pedalling technique doesn't matter. This is a valid, useful, result. So called "negative results" are common and useful in science, and don't imply "negative research."

Anyway, the original topic has a "positive result": leg extension is more efficient than leg flexion.

The fact is TDC can be replaced with maximal torque but for as long as they believe that this is impossible they will never discover how it can be done.

In physics maximal torque means maximum resistance. Maximum torque isn't interesting except for standing starts. It's not useful for endurance sports.

Why do you have to be a one trick pony, if you took time to learn both techniques,

This is where science helps: you get to stop wasting your time. Do it right the first time: Mash!

you would know how to relax your mashing muscles during the less stressful times in road races. Again I ask, how do you know this one legged rider used the mashing style when using the counterweight..

Something has to lift the counterweight. You have to overcome gravity. That "something" can only be his mashing muscles unless he gets off the bike and starts using his arms. An alternative is a fixed wheel bike, where wheel momentum could lift the weight. You could always mail the researches and ask them: "Did he use his arms to lift the weight?"

 

[JayKosta]

Re: New study shows leg flexion less efficient than extensio

...
This data is highly relevant to the discussion of pedaling technique and motor skill acquisition because it shows that all the cyclists we have tested (from recreational to elite) CAN pull up enough to produce positive pedal power during flexion but they CHOOSE not too do so when pedaling at endurance level powers. Repeat, everyone already knows how to pull up with power. They don't need split cranks or drills to learn how. Why do they choose not to pull up more? I don't know for sure but one explanation would be because their perceptual feedback tells them its less efficient to do so as all studies have shown.
PhitBoy

--------------------------
That would imply that 'pulling-up' when pedaling at more than endurance power is a typical 'technique'.

If cyclists trained with a technique of pulling-up (or complete unweighting) when at endurance power, wouldn't their efficiency using that technique increase? An important goal for competitive cyclists is to develop the technique that gives them the best blend of power and endurance for their chosen situations and events.

Jay Kosta
Endwell NY USA

 

[FrankDay]

Re: New study shows leg flexion less efficient than extensio

...
This data is highly relevant to the discussion of pedaling technique and motor skill acquisition because it shows that all the cyclists we have tested (from recreational to elite) CAN pull up enough to produce positive pedal power during flexion but they CHOOSE not too do so when pedaling at endurance level powers. Repeat, everyone already knows how to pull up with power. They don't need split cranks or drills to learn how. Why do they choose not to pull up more? I don't know for sure but one explanation would be because their perceptual feedback tells them its less efficient to do so as all studies have shown.
PhitBoy

--------------------------
That would imply that 'pulling-up' when pedaling at more than endurance power is a typical 'technique'.

If cyclists trained with a technique of pulling-up (or complete unweighting) when at endurance power, wouldn't their efficiency using that technique increase? An important goal for competitive cyclists is to develop the technique that gives them the best blend of power and endurance for their chosen situations and events.

Jay Kosta
Endwell NY USA

Actually, pulling up is typical technique at all powers. It is only at higher powers that riders (and you have to be connected to the pedals to do this) "pull up" hard enough to apply positive force to the pedal, e.i, go beyond partial unweighting.

Anyhow, your last paragraph indicates you are starting to understand the issue and thinking about it properly, asking the right questions. Congratulations.

 

[JayKosta]

Another 'thought' occured to me regarding the types of training that cyclists use -
Many (most?) of the typical training regimens are similar to actual 'on the road situations' that are encountered in competition, such as:intervals of various intensity and duration, hills, sprints, TT, etc.

Most intensive training of this sort is not usually considered to be pleasant or enjoyable, but we recognize that even though it is 'hard to do', that it will be of benefit because we have witnessed how lack of ablility in those areas has resulted in less performance.

Regarding strong 'pulling-up' - the 'value' of this ability is less obvious because most people don't use it except in extreme situations, and even then don't recognize it as something that might be improved by specific training.
And they probably know from experience that trying to train themself to do it is difficult and unpleasant.
So why bother unless they are convinced that it would be valuable?

This might be similar to the recent increase in 'core' strength training that many cyclists (and other athletes) are doing.
In prior years there was little interest in core training, but now it is thought to be useful and has become somewhat 'mainstream'.

Jay Kosta
Endwell NY USA