Calf muscles - is it worth working on them?



I have a question that I don't think has been answered yet in this thread drift(a bit disjointed at times). Suppose a person does engage more little muscles by changing their pedaling style, emphasizing something like scraping at the bottom of the pedal stroke, what is the cost of asking little muscles to exert force "tangentially" instead of just letting the big muscles push in the direction they are best at pushing, straight down? Why not just let the big quad muscles push straight down and save the energy taken by asking little muscles to pull or push somewhat sideways/laterally? And if there is improvement in something like a 40kTT, what about for a sprint, or all-out 4 minute effort, and at cadences over 110?
 
squidwranglr said:
Why do you keep harping on this point?

First, you seem to find the idea of theoretical evidence (as opposed to experimental or investigative results, such as biopsies), acceptable for making your point about PowerCranks, but not acceptable for the Coyle paper.

No, Coyles conjecture is just as valid as anyone elses based upon the theoretical evidence. While it may have already been shown that cycling efficiency can vary based upon muscle type I don't believe it has been experiementally shown that cyclists can actually change their muscle type enough through training to affect cycling efficiency to this degree. Therefore, until such has been demonstrated, this explanation must be considered pure conjecture, especially as long as other perfectly plausible explanations exist. Unfortunately, Coyle failed to mention any other "theoretical basis" for this improvement even though he knows they exist. What I really object to are those who should know better who come here and contend this paper actually proves anything along this point.

squidwranglr said:
Second, you make it sound like Coyle is hiding the fact that no biopsies were made and that Andy agreeing with you is confirmation of some secret that only you knew of. Did you actually read the paper? Coyle indicates very clearly:

"Muscle samples were not surgically obtained from this athlete to directly test the hypothesis that muscle fiber-type conversion contributed to the large increases in mechanical or muscular efficiency when cycling."

and goes on to offer conclusions based on theoretical evidence as to why a muscle fiber conversion may account for the gains in Armstrong's efficiency.

Berend

Coyle, at least, knows his conclusion is conjecture. Coggan and others who keep bring this paper up as "proving" something don't seem to realize this, just as they don't seem to realize that in the first paper, oft quoted here, that Coyle never claimed this data proved that one way of pedaling is superior to another. Yet, that is what continually gets posted here and at other places.

My comment on "Andy" agreeing with me simply goes back to many many debates I have had with him on this subject where he has consistently denied that efficiency is important to cyclists (or that it is possible to change same by changing pedaling technique or anything else) coming from the "just push harder" school of pedaling derived from his misinterpretation of the earlier Coyle paper. It is nice to hear him say something other than these papers of Coyle "prove" his bias. At least he seemingly agrees with me now, they do not.
 
WarrenG said:
I have a question that I don't think has been answered yet in this thread drift(a bit disjointed at times). Suppose a person does engage more little muscles by changing their pedaling style, emphasizing something like scraping at the bottom of the pedal stroke, what is the cost of asking little muscles to exert force "tangentially" instead of just letting the big muscles push in the direction they are best at pushing, straight down? Why not just let the big quad muscles push straight down and save the energy taken by asking little muscles to pull or push somewhat sideways/laterally? And if there is improvement in something like a 40kTT, what about for a sprint, or all-out 4 minute effort, and at cadences over 110?

It does no good to let those quad muscles push down hard at the very bottom of the stroke where they can do absolutely zero work. If so you are expending a lot of energy and doing no work so it is very inefficient. As the direction of the applied force becomes less and less tangential to the pedaling circle the efficiency of the conversion of that force into work going to the wheel becomes less and less. What is important is how much energy you get to the wheel, not how much energy you expend trying to get energy to the wheel.

Further, it requires no more total energy to redirect the forces since all downward pedaling force comes from the combination of two major muscle groups with different directions of force, the glutes and the quads. All one must do is change the coordination of the firing and force pattern of these muscles and the direction of force application can become more tangential without using more energy. The same applies on the upstroke where the two muscle groups involved at the hip flexors and hamstrings, athough the direction of force is much less important there compared to simple unweighting.

So, to answer your question. The cost can be the same but by changing the pattern of the muscle contractions the amount of energy transimtted to the wheel for this same effort can be greater. What is tough to do is actually learn how to make these changes, to become more efficient, but it can be done, as Luttrell has demonstrated.
 
WarrenG said:
Iwhat about for a sprint, or all-out 4 minute effort, and at cadences over 110?

Regarding this part of your question, let me give you an anecdote. A masters track cyclist just told me, after six years on my product, he was able to increase his top end cadence from 180 to 245. I can only conclude that is coming from better coordination, better anticipation of the direction changes the foot is required to make all around the circle.
 
Fday said:
Regarding this part of your question, let me give you an anecdote. A masters track cyclist just told me, after six years on my product, he was able to increase his top end cadence from 180 to 245. I can only conclude that is coming from better coordination, better anticipation of the direction changes the foot is required to make all around the circle.
I came real close to buying powercranks over the Winter, I bought a powertap instead. I made that decision based on need at the time, but my understanding of the powercrank was it was mostly to aid in the up portion of the stroke by engaging the hip flexor. The claims on the net were that the product even helped track and field sprinters by doing this. There is a product called the "sprint trainer" that uses weights on the thigh via a belt that claims to do more or less the same thing for running. The theory behind the sprint trainer is that the recovery and not the leg drive is the limiting factor in peak running speed. I think you should send Warren and I your product and we will conduct a study on sprinting:) Wait I think warren is busy with the Ergomo right now , just send them to me.
 
Billsworld said:
I think you should send Warren and I your product and we will conduct a study on sprinting:) Wait I think warren is busy with the Ergomo right now , just send them to me.
Didn't you know, Bill? They come with a Money Back Guarantee! :)
 
Fday said:
Didn't realize I funded that study. But, I guess you know.

You provided the cranks free of charge, correct? If so, that means that you funded the study, something that Luttrell et al. were ethically obligated to reveal, but did not. (If you didn't provide the cranks, then just say so, and I'll take back what I've said.)

Fday said:
Anyhow, there may not be any experimental evidence but there is plenty of theoretical evidence that the pattern of force application should influence efficiency.

Only in the minds of those who don't really understand the biomechanics of pedaling. Those who do realize that even untrained individuals tested before the existence of your product unweight on the upstroke, at least at exercise intensities comparable to those encountered in competition, and that any attempt to actually generate positive power during the upstroke is likely to be LESS efficient, not more.

Fday said:
Then, we have the problem of the Luttrell study. Something has to account for the efficiency improvements observed. It seems unlikely that fiber type was changed in 6 weeks so that leaves another explanation.

How about just coming into the lab and pedaling a cycle ergometer regularly?

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16293901&query_hl=3&itool=pubmed_docsum

Since Luttrell et al. didn't include an "attention control" group in their study or have a "run in" period to be sure that the subjects' efficiency wasn't changing over time, the above possibility can't be ruled.

Fday said:
While he did not measure pedal forces to be able to prove the efficiency changes occurred as a result of this change, do you have another potential explanation? It is the only thing I can think of.

See above.





Oh phooeey. Lots of papers get accepted with crazy interpretations. The fact that a paper gets published does not make it, or the conclusions it draws, true. At least you agree that no fibre type measurements were made so the conclusion is pure conjecture.





I didn't say the paper wasn't interesting and I agree it deserved to be published. I just stated that the conclusions regarding the basis of the efficiency improvements seen in Lance over this time were pure conjecture. I am glad you agree with me on that point. I am also glad you have finally, seemingly, come around to the viewpoint that increasing efficiency is important, however it is obtained.[/QUOTE]
 
acoggan said:
You provided the cranks free of charge, correct? If so, that means that you funded the study, something that Luttrell et al. were ethically obligated to reveal, but did not. (If you didn't provide the cranks, then just say so, and I'll take back what I've said.)

Well, I did provide him with free cranks for the study but, that study involved a lot more expense than getting the cranks. There are several studies underway (or soon to get underway) in which I have not provided free cranks, just to address this concern of yours. We will, hopefully, find out if this is a significant bias. Heck, I even offered to provide you with free cranks, even though I know your bias, so you could repeat and refute the study and you refused, saying it wasn't worth your time to do so. You would rather just bad mouth it and my product rather than do scholarly research.


acoggan said:
Only in the minds of those who don't really understand the biomechanics of pedaling. Those who do realize that even untrained individuals tested before the existence of your product unweight on the upstroke, at least at exercise intensities comparable to those encountered in competition, and that any attempt to actually generate positive power during the upstroke is likely to be LESS efficient, not more.

There is no such thing as an untrained individual. Everyone learned how to ride a bike when they were children, and they all learned how to partially unweight on the upstroke. When people started training for competition their method of pedaling has been ingrained for many many years and it is not so easy to undo so it is no surprise that there is little or no difference between "trained" and "untrained" individuals. And, you continue to misunderstand my product - probably because you refuse to study them, even though you should understand it as I know you have ridden on them at least once. It does not try to teach people how to generate positive power on the upstroke, at least all the time, but only teaches them how to completely unweight on the upstroke, big difference. This complete unweighting, however, is putting potential energy into that leg that is being retrieved on the downstroke, so people are getting power out of this action, just not directly. This change is only a small increase in the lifting that people are already doing, but it makes for large efficiency gains. I am surprised you cannot see this. Wait, no I am not.



acoggan said:
How about just coming into the lab and pedaling a cycle ergometer regularly?

http://www.ncbi.nlm.nih.gov/entrez/..._uids=16293901&query_hl=3&itool=pubmed_docsum

Since Luttrell et al. didn't include an "attention control" group in their study or have a "run in" period to be sure that the subjects' efficiency wasn't changing over time, the above possibility can't be ruled.

What on earth does that study have to do with the Luttrell study. They examined the effects of training on sedentary women ("We conclude that mechanical efficiency of cycling increases with training in women previously unfamiliar with cycling, and that the WE index is less sensitive to this training effect than GE and NE indices."). In fact, this study is supportive of the Luttrell study since it looked at two different methods of training and found that one was more effective at improving GE. Luttrell had two matched groups of trained cyclists. One group trained on an ordinary bike and the other a PC equipped bike 3 hours a week and differences were observed in gross efficiency in 6 weeks in the PC group and not in the control. Anyhow, if there were deficiencies in the study that should be addressed by follow on studies. If you would like to purchase a pair so I don't inject any bias into your study I would love to see you do this. Since you refuse to do this study (even though I have offered you free cranks to do so, despite the fact I know your bias), it will have to be left up to others to "prove" the Luttrell study was poppycock or not. I think those studies are underway. We will all hold our breath until they are published. Wait, I am not holding my breath. I am not worried what they will show.
 
frenchyge said:
Didn't you know, Bill? They come with a Money Back Guarantee! :)
I think they are an interesting idea. In my case where increasing power at high cadence is what its all about, its hard to argue what part of the circle that the power is made. What if you could train the brain to not give up that part of the circle and make more power in the rest of it. I am not saying it can be done. Ok I am dizzy now.:)
 
Billsworld said:
I came real close to buying powercranks over the Winter, I bought a powertap instead. I made that decision based on need at the time, but my understanding of the powercrank was it was mostly to aid in the up portion of the stroke by engaging the hip flexor. The claims on the net were that the product even helped track and field sprinters by doing this. There is a product called the "sprint trainer" that uses weights on the thigh via a belt that claims to do more or less the same thing for running. The theory behind the sprint trainer is that the recovery and not the leg drive is the limiting factor in peak running speed. I think you should send Warren and I your product and we will conduct a study on sprinting:) Wait I think warren is busy with the Ergomo right now , just send them to me.

Are you talking running sprinting or cycling sprinting. Actually, in running improvement, which we see a lot of. Those runners who have analyzed them (this includes Alberto Salazar, who bought a pair for coaching purposes) think the improvement comes mostly from form and efficiency (just like cycling, what a surprise) improvement, not just muscle training. I can send you a video of a discussion on this (it has been taken off the web, although I am trying to get it back on) if you will email me and ask for it. I cannot send it til next week because I am traveling at Calif 70.3 expo right now and the video is on my computer at home. (or, if you are in SC, come by the expo and see it on DVD). Most of our triathletes report seeing running improvement starting in about 2 weeks, way before they are seeing cycling improvement. The world-class sprinter on my video took 0.2 seconds of the american age record for the 100m dash 4 months after starting PC's to help him recover from injury, running 10.34 at the age of 38. Last year we got Joey Galloway of the NFL on them (the so called fastest man in the NFL) and he had a record setting season. Most marathoners are seeing about a minute per mile in 3 months or so. Running improvements are even more significant that the cycling improvements and they come much faster. I just got a small group with very elite distance runners on them (includes some Olympic medalists) so, hopefully, we will soon be seeing what the potential is in the very elite runner.
 
Billsworld said:
I think they are an interesting idea. In my case where increasing power at high cadence is what its all about, its hard to argue what part of the circle that the power is made. What if you could train the brain to not give up that part of the circle and make more power in the rest of it. I am not saying it can be done. Ok I am dizzy now.:)

Many years ago Phil Holman was a huge nay-sayer on one of these discussion groups. I challenged him to train on them exclusively and report on his results. That thread is still available. In 7 months he increased his top speed on the track from 35 to 38 mph and his pursuit from 30 to 32 and won a bronze medal at master's worlds.
 
Fday said:
Regarding this part of your question, let me give you an anecdote. A masters track cyclist just told me, after six years on my product, he was able to increase his top end cadence from 180 to 245. I can only conclude that is coming from better coordination, better anticipation of the direction changes the foot is required to make all around the circle.

I am a masters National Champion track sprinter and I can tell you that a cadence above 180 is not used in competition. 135-160 being pretty much the entire range used in competition by top masters sprinters. I do not understand why someone would care about being able to go to 245. I have seen many, many track sprinters go to very high cadences as a result of many hours training at high cadences on rollers and during other low resistance efforts.
 
Fday said:
Well, I did provide him with free cranks for the study but, that study involved a lot more expense than getting the cranks.

The latter fact doesn't matter: you still helped underwrite the cost of the study, a fact that should have been indicated by the authors.

Fday said:
There are several studies underway (or soon to get underway) in which I have not provided free cranks, just to address this concern of yours. We will, hopefully, find out if this is a significant bias.

It is certainly a potential bias...which is why, ethically-speaking, it should have been revealed.

Fday said:
Heck, I even offered to provide you with free cranks, even though I know your bias, so you could repeat and refute the study and you refused, saying it wasn't worth your time to do so. You would rather just bad mouth it and my product rather than do scholarly research.

I don't recall any such conversation, and I don't recall bad-mouthing your product (although I do obviously question its usefulness).

Fday said:
There is no such thing as an untrained individual. Everyone learned how to ride a bike when they were children, and they all learned how to partially unweight on the upstroke.

Fully unweight, actually, at least at higher exercise intensities. But again, that's why, at least with respect to cycling, your product seems to be a solution in search of a problem.

Fday said:
When people started training for competition their method of pedaling has been ingrained for many many years and it is not so easy to undo so it is no surprise that there is little or no difference between "trained" and "untrained" individuals.

Given that the firing sequence of different muscles, etc., is nearly identical between walking/running and pedaling, I'd say it has much more to do with evolution than what we did as little kids.

Fday said:
And, you continue to misunderstand my product - probably because you refuse to study them, even though you should understand it as I know you have ridden on them at least once. It does not try to teach people how to generate positive power on the upstroke, at least all the time, but only teaches them how to completely unweight on the upstroke, big difference.

But people already largely, if not entirely, unweight the pedal on the upstroke, so what's the purpose of your cranks if not to "...teach people how to generate positive power on the upstroke..."?

Fday said:
This complete unweighting, however, is putting potential energy into that leg that is being retrieved on the downstroke

Regardless of how the leg arrives at the top of the pedal stroke, it has exactly the same potential energy. Moreover, the kinetic energy of the leg is also always going to be essentially the same, because if your leg were traveling markedly slower at that point of the pedal cycle versus another than your freewheel/freehub would disengage, and it can't travel markedly faster at that point because that would require the bike to shoot forward at an impossibly high (given human power output) rate of acceleration.

Fday said:
, so people are getting power out of this action, just not directly. This change is only a small increase in the lifting that people are already doing, but it makes for large efficiency gains. I am surprised you cannot see this. Wait, no I am not.

The only reason you "see" such a large potential for gains in efficiency here is because you don't really understand the biomechanics of pedaling. Those that do - e.g., Jim Martin, Jeff Broker - don't see what you see.


Fday said:
What on earth does that study have to do with the Luttrell study.

It illustrates that training alone can improve efficiency, and in a fairly short period of time at that.

Fday said:
Luttrell had two matched groups of trained cyclists. One group trained on an ordinary bike and the other a PC equipped bike 3 hours a week and differences were observed in gross efficiency in 6 weeks in the PC group and not in the control.

Except that the control group didn't also come into the lab and pedal under the supervision (coaching?) of the investigators.

Fday said:
Anyhow, if there were deficiencies in the study that should be addressed by follow on studies.

That's good to hear, because that is how science is supposed to work.

Fday said:
If you would like to purchase a pair

No thanks. I see no reason to expect that my own performance would improve as a result of using them, and I don't have the resources/time/motivation to conduct a formal study of them.
 
Fday said:
It does no good to let those quad muscles push down hard at the very bottom of the stroke where they can do absolutely zero work. If so you are expending a lot of energy and doing no work so it is very inefficient. As the direction of the applied force becomes less and less tangential to the pedaling circle the efficiency of the conversion of that force into work going to the wheel becomes less and less.

Yes, I agree with that. I wasn't suggesting letting the quad muscle do much more than push straight down because that's where I can get the most power for the least energy expended.

Fday said:
What is important is how much energy you get to the wheel, not how much energy you expend trying to get energy to the wheel.

I disagree. My energy stores are limited, whether it's during a sprint, an all-out one minute effort, or any other effort that uses up some of my available energy supply.

Fday said:
Further, it requires no more total energy to redirect the forces since all downward pedaling force comes from the combination of two major muscle groups with different directions of force, the glutes and the quads. All one must do is change the coordination of the firing and force pattern of these muscles and the direction of force application can become more tangential without using more energy.

It seems like first you say the quads are best at pushing straight down but here it sounds like you're trying to say I should also train them to push at an angle. No matter how much time I spend getting my quads to push better tangentially I'll never get as much power for energy as when they're pushing straight down, yes? So why not let them rest and save them until they're in position to do what they can do best?

How's this for an analogy? If i try to lift a 20 pound weight one foot vertically with one arm, is it harder doing it with my arm in it's most effective/efficient position of being bent 90 degrees at the elbow, or with my arm extended straight out? (Using big muscles vs. little muscles)
 
Fday said:
Many years ago Phil Holman was a huge nay-sayer on one of these discussion groups. I challenged him to train on them exclusively and report on his results. That thread is still available. In 7 months he increased his top speed on the track from 35 to 38 mph and his pursuit from 30 to 32 and won a bronze medal at master's worlds.
I looked into them for cycling. and read about some of the examples of runners that you are talking about. I decided on the powertap as a better use of resources and to keep myself from going bonkers in the winter. I was going to use them on my road bike which is easier to train on in the winter here, becuase gear selection is so easy and sometimes the sprints are done as close to the house as possable.(Cold) The reason I didnt buy them was that it wasnt clear to me that I could lock them and sprint normally on the road, and maybe do some standing starts. The answers I got led me to think that I might break them doing so. Warren G s question about higher cadence intervals was more or less what I was thinking would be the best use for them too
 
Billsworld said:
I looked into them for cycling. and read about some of the examples of runners that you are talking about. I decided on the powertap as a better use of resources and to keep myself from going bonkers in the winter. I was going to use them on my road bike which is easier to train on in the winter here, becuase gear selection is so easy and sometimes the sprints are done as close to the house as possable.(Cold) The reason I didnt buy them was that it wasnt clear to me that I could lock them and sprint normally on the road, and maybe do some standing starts. The answers I got led me to think that I might break them doing so. Warren G s question about higher cadence intervals was more or less what I was thinking would be the best use for them too

The "dual mode" option is somewhat new for us and I try to discourage it for most athletes as it makes it too easy to get lazy in training and training is supposed to be hard. Although I accept there are some situations where it is appropriate and optimal. You have to remember that the clutch we use is not capable of taking everything you can through at it, but it stands up to most demands and, interestingly, the pros hardly ever break these things (I think Magnus Backstadt has broken one in two years). The typical time most users break the clutch is at about 4 to 6 months when they are starting to really ride them hard and are not real smooth year or are starting hard from a stop light. So, PowerCranks are not going to reliably stand up to training your standing starts. You will have to use regular cranks for that (the lock-up mode might work for this although the clutch takes some load, even in lock-up mode so, there could be a theoretical clutch problem for extreme stresses such as seen in a track start (you won't know if the clutch failed until you unlock them again). If you get them and do this successfully, let me know so I can tell others. However, they will normally stand up to training for sprinting, pursuit, and endurance stuff of even the biggest riders.
 
WarrenG said:
I disagree. My energy stores are limited, whether it's during a sprint, an all-out one minute effort, or any other effort that uses up some of my available energy supply.


Perhaps I was not clear. Of course it is important how much energy you expend. What is important is how much of that expended energy gets to the wheel. That is what efficiency is all about. If one can modify the pedaling dynamic and become more efficient then one is getting more energy to the wheel for the same amount of energy expended or expending less energy for the same amount to the wheel. Does that make more sense to you?

WarrenG said:
It seems like first you say the quads are best at pushing straight down but here it sounds like you're trying to say I should also train them to push at an angle. No matter how much time I spend getting my quads to push better tangentially I'll never get as much power for energy as when they're pushing straight down, yes? So why not let them rest and save them until they're in position to do what they can do best?

How's this for an analogy? If i try to lift a 20 pound weight one foot vertically with one arm, is it harder doing it with my arm in it's most effective/efficient position of being bent 90 degrees at the elbow, or with my arm extended straight out? (Using big muscles vs. little muscles)

The quads do not push down, they extend the knee. The direction of the forces the foot puts on the pedal depends upon the combination of the two main driver forces, the glutes and the quads and the position of the leg when they are contracting. The direction of the force will depend upon the combination of these two muscles together. One can change the direction of the force simply by contracting the glutes more or less or the quads more or less. When the hip is flexed at the top of the stroke, contracting the quads will move the foot forward, not down, which would be in a direction tangential to the pedal circle but contracting the glutes will push the foot down perpendicular to the pedal circle. At the top of the arc contracting the glutes too soon is inefficient and contracting the quads too late is inefficient. Where, when near the bottom of the stroke, contracting the glutes is moving the foot backwards and contracting the quads is moving the foot more downward. This is a dynamic system and what happens with any particular muscle contraction (or combination of contractions) is different throughout the entire circle. It is not something you can really think about and optimize while you are doing it at 100 rpm. That is why it is so hard to change and improve.

Does this make more sense?
 
Boy, this is going to be a long one. Anyhow, here goes.

acoggan said:
The latter fact doesn't matter: you still helped underwrite the cost of the study, a fact that should have been indicated by the authors.

You are correct.

acoggan said:
It is certainly a potential bias...which is why, ethically-speaking, it should have been revealed.

You are correct.

acoggan said:
I don't recall any such conversation, and I don't recall bad-mouthing your product (although I do obviously question its usefulness).

I think that is called selective memory. I believe that offer was made many years ago on RBR and again on SlowTwitch.

acoggan said:
Fully unweight, actually, at least at higher exercise intensities. But again, that's why, at least with respect to cycling, your product seems to be a solution in search of a problem.

How does one fully unweight when one is using platform pedals (how everyone learns) and maintain contact with the pedal to be ready for the downstroke as soon as over the top? I thought the oft cited Coyle study proved that the most elite cyclists did not fully unweight on the upstroke. What are you talking about here?

Given that the firing sequence of different muscles, etc., is nearly identical between walking/running and pedaling, I'd say it has much more to do with evolution than what we did as little kids.
Yes, it is clear the firing sequence of these muscles is similar between these disciplines. However, the intensity of the various muscle contractions is quite different and the intensity of the various contractions is what primarily determines differences in form (which probably explains why we have such a big running impact compared to ordinary cycling).



acoggan said:
But people already largely, if not entirely, unweight the pedal on the upstroke, so what's the purpose of your cranks if not to "...teach people how to generate positive power on the upstroke..."?

They do. I agree people largely unweight but I disagree that they entirely unweight. How long did you last when you tried the cranks again? Anyone who completely unweights on the upstroke would have no trouble riding my cranks. The typical first ride for most new users is 10-15 minutes, for most pros 20-30 minutes although, infrequently, someone can go over an hour.

acoggan said:
Regardless of how the leg arrives at the top of the pedal stroke, it has exactly the same potential energy. Moreover, the kinetic energy of the leg is also always going to be essentially the same, because if your leg were traveling markedly slower at that point of the pedal cycle versus another than your freewheel/freehub would disengage, and it can't travel markedly faster at that point because that would require the bike to shoot forward at an impossibly high (given human power output) rate of acceleration.

You are correct there, the potential energy at the top is the same. However, the question is where did the energy come from to put that potential energy into the leg. It can come from only two sources. either internally from itself or, if that is not sufficient, it must be transferred across the axle though the cranks and come from the leg pushing down, robbing from the energy that can be throughput to the wheel.

And, you are crazy when you talk about the kinetic energy being essentially the same. Do the math. The problem is the thigh and the lower leg have substantially different masses. And, besides, this issue has nothing to do with this discussion, you are only trying to obfuscate the matter for most here.



acoggan said:
The only reason you "see" such a large potential for gains in efficiency here is because you don't really understand the biomechanics of pedaling. Those that do - e.g., Jim Martin, Jeff Broker - don't see what you see.

Ugh, I can't help what they can't see. What I do see are huge improvements reported by users that go way beyond the normal training expectations and in some studies (Luttrell and other unpublished data) and am trying to explain where these come from. You are, of course, free to ignore these reports if you choose. Not much of a scientific curiosity there me thinks though.

acoggan said:
It illustrates that training alone can improve efficiency, and in a fairly short period of time at that.

So, a study that shows training can improve pedaling efficiency in the untrained has meaning to you to criticize a study of trained cyclists where both groups train but only one sees efficiency improvements? Geez, why don't you use this study to criticize the conclusions of Coyle in explaining Lances documented efficiency improvements. No one trained more than him so it is reasonable, using this logic, that these observed improvements should have come just from his training, no need to invoke changes in fibre type.


acoggan said:
Except that the control group didn't also come into the lab and pedal under the supervision (coaching?) of the investigators.

I thought they did. If they didn't then so be it and someone else will have to do that (and, you will probably be relieved to hear, I think those are underway).
 
Fday said:
Perhaps I was not clear. Of course it is important how much energy you expend. What is important is how much of that expended energy gets to the wheel. That is what efficiency is all about. If one can modify the pedaling dynamic and become more efficient then one is getting more energy to the wheel for the same amount of energy expended or expending less energy for the same amount to the wheel. Does that make more sense to you?

Better, but you seem to be suggesting that I ask my quads to contract/fire/move (use energy) in ways during some parts of the pedal circle that are not nearly as efficient as if I just ask them to contract/fire/move in the directions they are best suited for. IOW, it sounds like I'm using some of my available energy by asking my quads to move in ways that are not maximally efficient-some parts of the circle are substantially more efficient than other parts, so why waste my energy for those less efficient parts of the circle?

For example, let's say that when my foot is between 1 o'clock and 5'oclock my quads are in position to exert 100 units of force on the pedals, and during all other portions of the circle it ranges from 0 to 50 units of force (I know it's not this segmented), but after I use PC's for awhile I can raise that to 0-70 units of force during the other periods of the pedal circle. So why waste my energy resources during periods when the most I can apply is 70 units. Wouldn't I rather just save my energy for the periods when I can apply 100 units?

It sounds like you're focused on getting the most out of one pedal stroke or a period of time, whereas I am focussed on getting the most out of a high number of pedal strokes (fewer at higher power) where my energy stores and muscle fatigue are limited and so must be conserved as much as possible by not wasting the energy and fatigue trying to use them during less efficient portions of the pedal circle.
 
WarrenG said:
Better, but you seem to be suggesting that I ask my quads to contract/fire/move (use energy) in ways during some parts of the pedal circle that are not nearly as efficient as if I just ask them to contract/fire/move in the directions they are best suited for. IOW, it sounds like I'm using some of my available energy by asking my quads to move in ways that are not maximally efficient-some parts of the circle are substantially more efficient than other parts, so why waste my energy for those less efficient parts of the circle?

For example, let's say that when my foot is between 1 o'clock and 5'oclock my quads are in position to exert 100 units of force on the pedals, and during all other portions of the circle it ranges from 0 to 50 units of force (I know it's not this segmented), but after I use PC's for awhile I can raise that to 0-70 units of force during the other periods of the pedal circle. So why waste my energy resources during periods when the most I can apply is 70 units. Wouldn't I rather just save my energy for the periods when I can apply 100 units?

It sounds like you're focused on getting the most out of one pedal stroke or a period of time, whereas I am focussed on getting the most out of a high number of pedal strokes (fewer at higher power) where my energy stores and muscle fatigue are limited and so must be conserved as much as possible by not wasting the energy and fatigue trying to use them during less efficient portions of the pedal circle.

I didn't know that the efficiency of contracting the quads varied depending upon where the foot is on the pedal circle. By my understanding, the energy required by a contracting muscle depends mainly upon 3 things, the mass being contracted, the force of contraction, and the speed of contraction. The force the quads can exert on the pedals depends also on what the glutes are doing. The amount and direction of the force on the pedals depends upon the combination of these two muscles. So, it is not quite so simple. Further, power is the amount of work you are doing per unit time and the amount of work you do is the tangential force you exert on the pedals through a certain distance. So, it really is better to exert a force of 70 units through half the arc than a force of 100 units through a quarter of the arc. And, if that higher force of 100 units is not optimally directed tangentially, then you may only be getting an effective force of 70 units. It is not the size of the muscle force that matters but how much energy gets through to the wheel. There is probably no advantage to "saving your energy" so you can exert somewhat more force over a smaller portion of the arc.

I am focused on getting the most out of the engine. If one can get the most out of each single pedal revolution then that efficiency will carry over to getting more out of the engine whether you are riding at a cadence of 75 or 100.