New study shows leg flexion less efficient than extension.

[FrankDay]

Re: Re:

the evidence upon which I base by conclusions was posted here by Dr. Coggan.

Not to my recollection. (Not that it really matters, since it appears correct...I just don't wish to be inadvertently credited for somebody else's work.)

Yes, you are correct. My memory let me down. That graph was originally posted by Dr. Martin himself September 9, 2014 in the PowerCranks thread. http://forum.cyclingnews.com/viewto...ng+leg+flexion+is,+in+fact,+positive#p1571712 It seems to me that you posted the vector diagram of this data, although I can't find it for now (edit: found it in the pedaling technique thread: http://forum.cyclingnews.com/viewtopic.php?p=1639586#p1639586).

Still not entirely correct. The colored diagram is indeed Jim's data, but the "clock" diagram is the classic one from Jeff Broker.

Forgive my failure here. Perhaps it is understandable in view of what you wrote when you posted it.

Better still, look at the same data after correcting for the non-muscular components (which proves you wrong):

The bold is in the original.

 

[FrankDay]

Re: Re:

...
I would agree with your assertion that it's probably because they had 3 years more training experience that lead them to find the most efficient way to pedal

Hugh

----------------------------------------------------
So it does take considerable training experience to find the most effective way?
If that's the case then perhaps some training/coaching about efficient pedaling would shorten the learning curve.

Jay Kosta
Endwell NY USA

Did you missed the ? I'd contend that it's very natural to "find" one's one efficient technique rather quickly with very little if any to gain via specific interventions into technique. The fact that a good number of very inexperienced cyclists exhibit efficiencies very close to the maximum conceivable of ~25% tells me that factors other than technique such as fiber composition are responsible for the variation one sees in cyclists GME.

Hugh

Do you have any support for the bolded text?

 

[FrankDay]

Re: Re:

Another thing that amuses me about this thread. Dr. Coggan a few posts back comes here and posts that the counterweighted single-legged system reproduces bilateral pedaling well because Dr. Martin has found this to be a case.

Fixed that part for you.

can you provide a link to where he has demonstrated this? I found a link to a study done by one of his students in which he says this: "Benefits of single-leg cycling may be compromised because single- and double-leg cycling are biomechanically different. Specifically, during normal double-leg (2L) cycling the gravitational forces acting on each leg are essentially balanced by the contralateral limb and thus do not require active leg flexion. Conversely, single-leg (SL) cycling requires active leg flexion." The assumption here is that riders do not unweight (because they don't have to) when riding double legged but this is demonstrably wrong. I look forward to seeing how well Dr. Martin's findings stand up to scrutiny.

He posts this in a thread about a study that shows that counterweighted single legged pedaling doesn't reproduce bilateral pedaling.

That's not what this thread is originally about (cf. the thread title), and as I said, I find the results of the study introduced subsequently a bit surprising, based on both what I've been told by a world-class expert on cycling biomechanics (hi Jim!) and my own experience/experiments. (The difference could be that Jim has focused on resultant joint powers, whereas that abstract emphasizes differences in iEMG activity.)

You are correct, the original study that started this thread was on a different topic. The other was introduced later. Either way, it had been introduced into the thread and you just chose to ignore it. I look forward to seeing Dr. Martin's work in this regards (once you provide a link) and to see how it compares to the other study. Here is an interesting tidbit that comes from the Masters thesis done by a Larry Thomas in Dr. Martin's lab in 2011

Counterweighted single-leg cycling provides a model that can be performed assimilating normal double-leg cycling. Unfortunately, due to limited practice sessions and perhaps not experimenting with a wide enough range of counterweights, I was unable to show the single-leg cycling model as not significantly different from normal double leg cycling.(emphasis added)

 

[JayKosta]

Re: Re:

So it does take considerable training experience to find the most effective way?
If that's the case then perhaps some training/coaching about efficient pedaling would shorten the learning curve.

No that would be a waste of time. All the studies where they have tried to improve pedalling technique through chaining shape, uncoupled cranks, coaching pedalling technique etc have proved unsuccessful.

And in practice those that claim that pedalling technique can be improved have simply failed so miserably they have to resort to weak anecdotes or blatant lies about their products.

--------------------
My understanding from the above is that your opinion (based on your experience, education, study, etc.) is

"that 'average' cyclists who are striving to increase their performance thru self-directed training already 'know' what the optimal pedaling technique would feel like. And without any special 'external' interventions they will acquire the strength and endurance to acheive (or at least continue to approach) that optimal technique"

is that a reasonable statement of your view?

Jay Kosta
Endwell NY USA

 

[CoachFergie]

No. It is not.

You are being mislead by people like Frank and Noel that there is an optimal technique that one can learn compared to the obvious concept (based on the data, not my opinion) that pedalling technique is learned quickly and that improved performance comes from training, recovery, nutrition and strong mental skills.

Focusing on pedalling technique is a red herring.

 

[JayKosta]

Re:

No. It is not.

You are being mislead by people like Frank and Noel that there is an optimal technique that one can learn compared to the obvious concept (based on the data, not my opinion) that pedalling technique is learned quickly and that improved performance comes from training, recovery, nutrition and strong mental skills.

Focusing on pedalling technique is a red herring.

-----
Thank you,
Jay Kosta
Endwell NY USA

 

[FrankDay]

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

 

[backdoor]

Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Coapman here, this is the only way I could get back to the forum since changes in March. My attempt in the LOGIN section failed.
My question is, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c without using the hip flexors. It is possible.

 

[backdoor]

Re: Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Coapman here, this is the only way I could get back to the forum since changes in March. My attempt in the LOGIN section failed.
My question is, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c without using the hip flexors. It is possible.

Question should read, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c by making use of the hip flexors or the other leg.

 

[FrankDay]

Re: Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Coapman here, this is the only way I could get back to the forum since changes in March. My attempt in the LOGIN section failed.
My question is, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c without using the hip flexors. It is possible.

Question should read, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c by making use of the hip flexors or the other leg.

I am not sure what you are asking. Increasing the kinetic energy of any object requires putting energy into that object. Accelerating the leg from 6 to 9 increases the kinetic energy of the leg (just as happens in the other leg at the same time from 12 to 3). Therefore, it is not possible to eliminate this task.

 

[CoachFergie]

Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Ahhh no, we do not agree. Continue to delude yourself at will and people are free to delude themselves that their Gimmickcrank purchase is having any influence on performance.

The original post outlines a study that does an excellent job of disproving many of your bogus claims.

Science 1 - Gimmick Peddlers 0

 

[CoachFergie]

It's pretty simple. We have an excellent case study where a guy does 7 years of immersion training pedalling more like one does on uncoupled cranks and when he changes to a way of pedalling more like how people normally pedal leads to an instant drop in metabolic cost and an increase in efficiency.

Science 1 - Gimmick Peddlers 0

 

[backdoor]

Re: Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Coapman here, this is the only way I could get back to the forum since changes in March. My attempt in the LOGIN section failed.
My question is, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c without using the hip flexors. It is possible.

Question should read, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c by making use of the hip flexors or the other leg.

I am not sure what you are asking. Increasing the kinetic energy of any object requires putting energy into that object. Accelerating the leg from 6 to 9 increases the kinetic energy of the leg (just as happens in the other leg at the same time from 12 to 3). Therefore, it is not possible to eliminate this task.

When you increase the pedalling power stroke from 120 to 180 degrees, the foot of the idling leg can be drawn back and upward from 5 to 9 o'c using the swinging action of the lower leg.

 

[JayKosta]

Re:

It's pretty simple. We have an excellent case study where a guy does 7 years of immersion training pedalling more like one does on uncoupled cranks and when he changes to a way of pedalling more like how people normally pedal leads to an instant drop in metabolic cost and an increase in efficiency.
...

--------------------------
That could just as well be used to speculate -

"doing immersion training with both legs on uncoupled cranks, and then changing to fixed cranks would give an instand drop in metabolic cost and an increase in efficiency"

"the additional training load imposed by uncoupled cranks results in a increased 'training effect' that is difficult to obtain with fixed cranks"

Jay Kosta
Endwell NY USA

 

[JayKosta]

Re: Re:

...
When you increase the pedalling power stroke from 120 to 180 degrees, the foot of the idling leg can be drawn back and upward from 5 to 9 o'c using the swinging action of the lower leg.

--------------------------------
Yes there is rotational momentum, but there is also gravity when going from 6 to 9 o'c.
And yes, the leg can be 'drawn back and upwards' which requires active muscle use to do the 'drawing'.
And the leg can also be 'pushed back and upwards' by the pedal from the active muscle use of the other leg.

Jay Kosta
Endwell NY USA

 

[JamesCun]

Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Quite a disingenuous and manipulative post, Frank. Wait until people have moved on and then jump in with a summary of the 'groups' discussion. Really tacky and unfortunately typical of your methods.

 

[FrankDay]

Re: Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Coapman here, this is the only way I could get back to the forum since changes in March. My attempt in the LOGIN section failed.
My question is, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c without using the hip flexors. It is possible.

Question should read, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c by making use of the hip flexors or the other leg.

I am not sure what you are asking. Increasing the kinetic energy of any object requires putting energy into that object. Accelerating the leg from 6 to 9 increases the kinetic energy of the leg (just as happens in the other leg at the same time from 12 to 3). Therefore, it is not possible to eliminate this task.

When you increase the pedalling power stroke from 120 to 180 degrees, the foot of the idling leg can be drawn back and upward from 5 to 9 o'c using the swinging action of the lower leg.

Yes and no. The rearward momentum of the swinging lower leg and foot can be transferred to the thigh to push it up. The problem is the mass of the thigh is substantially more than the mass of the lower leg such that there isn't enough momentum there to completely transfer all of the energy needed to push the thigh up. The momentum of the thigh moving up and down can be used to more completely bring the foot across the top and bottom without much (or any) muscle input but it doesn't work the other way around. There are always going to be losses making the pedals go around.

 

[FrankDay]

Re: Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Quite a disingenuous and manipulative post, Frank. Wait until people have moved on and then jump in with a summary of the 'groups' discussion. Really tacky and unfortunately typical of your methods.

So, let me get this straight. You don't have any quibble with the points I summarized, just the fact that I did it? You find that tacky, disingenuous and manipulative? OK...

At least Coachfergie said he disagreed and then ignored all of the points as to exactly what he disagreed with and why just going back to his usual rants about independent cranks, which are nowhere to be found in my summary.

 

[JamesCun]

Re: Re:

Now that this thread has died down can we all agree that:

1. isolated leg pedaling is substantially different than two legged pedaling.
2. counter balanced isolated leg pedaling is substantially different than two legged pedaling.
3. because the two above are substantially different than what people do when pedaling a bike that studies that look at this form of pedaling are unlikely to teach us much about two legged pedaling.
4. studies that measure actual pedal forces don't say much about what the muscles are doing unless they somehow account for the non-muscular forces applied to the pedals.
5. only the muscular forces involved in pedaling should have an effect on pedaling efficiency.

Quite a disingenuous and manipulative post, Frank. Wait until people have moved on and then jump in with a summary of the 'groups' discussion. Really tacky and unfortunately typical of your methods.

So, let me get this straight. You don't have any quibble with the points I summarized, just the fact that I did it? You find that tacky, disingenuous and manipulative? OK...

At least Coachfergie said he disagreed and then ignored all of the points as to exactly what he disagreed with and why just going back to his usual rants about independent cranks, which are nowhere to be found in my summary.

I didn't address your 5 points because I feel it was a disingenuous, manipulative and tacky post. Have a nice day Mr Day.

 

[backdoor]

Re: Re:

[quote="FrankDay




Question should read, how can you eliminate the task of having to accelerate the weight of the idling leg from 6 to 9 o'c by making use of the hip flexors or the other leg.

I am not sure what you are asking. Increasing the kinetic energy of any object requires putting energy into that object. Accelerating the leg from 6 to 9 increases the kinetic energy of the leg (just as happens in the other leg at the same time from 12 to 3). Therefore, it is not possible to eliminate this task.

When you increase the pedalling power stroke from 120 to 180 degrees, the foot of the idling leg can be drawn back and upward from 5 to 9 o'c using the swinging action of the lower leg.

Yes and no. The rearward momentum of the swinging lower leg and foot can be transferred to the thigh to push it up. The problem is the mass of the thigh is substantially more than the mass of the lower leg such that there isn't enough momentum there to completely transfer all of the energy needed to push the thigh up. The momentum of the thigh moving up and down can be used to more completely bring the foot across the top and bottom without much (or any) muscle input but it doesn't work the other way around. There are always going to be losses making the pedals go around.

http://forum.cyclingnews.com/viewtopic.php?p=1731215#p1731215

You are missing the point. More than momentum is used as the foot is swept back and up from 5 to 9. Only the weight of the lower leg and foot has to be raised, the upper leg is only raised from 9 to 11. This drawing back of foot at 5 and application of maximal forward force at 11 is a combined simultaneous action which means momentum is not required to assist in bringing foot across the top. The objective is to increase the gains and reduce the losses.

 

[CoachFergie]

Re: Re:

That could just as well be used to speculate -

"doing immersion training with both legs on uncoupled cranks, and then changing to fixed cranks would give an instand drop in metabolic cost and an increase in efficiency"

"the additional training load imposed by uncoupled cranks results in a increased 'training effect' that is difficult to obtain with fixed cranks"

That would be speculation.

But when we have data like the OP we have some pretty good evidence that mashing is less metabolically costly and more efficient than circular pedalling.

No one has provided any data suggesting otherwise. Supports what we have been saying all along.

 

[CoachFergie]

Re: Re:

When you increase the pedalling power stroke from 120 to 180 degrees, the foot of the idling leg can be drawn back and upward from 5 to 9 o'c using the swinging action of the lower leg.

Yes and no. The rearward momentum of the swinging lower leg and foot can be transferred to the thigh to push it up. The problem is the mass of the thigh is substantially more than the mass of the lower leg such that there isn't enough momentum there to completely transfer all of the energy needed to push the thigh up. The momentum of the thigh moving up and down can be used to more completely bring the foot across the top and bottom without much (or any) muscle input but it doesn't work the other way around. There are always going to be losses making the pedals go around.

You are missing the point. More than momentum is used as the foot is swept back and up from 5 to 9. Only the weight of the lower leg and foot has to be raised, the upper leg is only raised from 9 to 11. This drawing back of foot at 5 and application of maximal forward force at 11 is a combined simultaneous action which means momentum is not required to assist in bringing foot across the top. The objective is to increase the gains and reduce the losses.

Crikey, it's like two people arguing over which imaginary friend (or pet theory) is better

Data boys, or you don't get a seat at the adult table!

 

[backdoor]

Re: Re:

It's pretty simple. We have an excellent case study where a guy does 7 years of immersion training pedalling more like one does on uncoupled cranks and when he changes to a way of pedalling more like how people normally pedal leads to an instant drop in metabolic cost and an increase in efficiency.
...

--------------------------
That could just as well be used to speculate -

"doing immersion training with both legs on uncoupled cranks, and then changing to fixed cranks would give an instand drop in metabolic cost and an increase in efficiency"



Jay Kosta
Endwell NY USA

The problem here is your training is concentrated on your weakest muscles while your most powerful muscles are being neglected.

 

[backdoor]

Re:

It's pretty simple. We have an excellent case study where a guy does 7 years of immersion training pedalling more like one does on uncoupled cranks -----.

Science 1 - Gimmick Peddlers 0

There is a difference between alternate single leg pedalling and 'uncoupled cranks' pedalling and results should be different.

 

[JayKosta]

Re: Re:

...
But when we have data like the OP we have some pretty good evidence that mashing is less metabolically costly and more efficient than circular pedalling.
...

--------------------------------------------------
Do you think that the non-counterweighted single-leg technique used in the OP study is similar to typical two-leg circular pedaling on fixed cranks?
I believe the single-leg technique requires much more exertion on the up-stroke than would be done in two-leg circular.

Also, what are your thoughts about the amount of up-stroke muscle usage when 'mashing', or for other variations of 'non-circular'?
I ask this inorder to understand how much difference you think there is between mashing and circular.

Jay Kosta
Endwell NY USA