For the "pedaling technique doesn't matter crowd"

[FrankDay]

================
coapman,

Thanks for the info.
It will be interesting if/when someone who is adept at that pedaling technique is tested on a power meter that shows power in each sector.

Jay Kosta
Endwell NY USA

Yes it will be. It will be especially interesting to me to see the power go from "unweighting" at 10:59 to a maximum torque equivalent to most peoples 2-3 torque at 11:01. Didn't know muscles could do that.

 

[coapman]

Yes it will be. It will be especially interesting to me to see the power go from "unweighting" at 10:59 to a maximum torque equivalent to most peoples 2-3 torque at 11:01. Didn't know muscles could do that.

When cranks are in the 11-5 position, a simultaneous drawing back at 5 and application of force at 11 takes place. During the unweighting upstroke the brain is also preparing muscles for that instant application of force at 11. There is no problem, because power is coming from the hip and not from the knee as in natural pedalling. In P. Holman's reports on PC's, it is obvious that the training being done is "pulling up" and it took him 3 weeks before his muscles were capable of doing this over a distance and that was before any torque was being applied. How much stronger are those pulling up muscles capable of becoming. Why train muscles to apply torque on the upstroke when your other leg is supposed to be applying maximal torque. It makes far more sense to concentrate on applying torque in a sector when both legs are effectively idling.

 

[FrankDay]

In P. Holman's reports on PC's, it is obvious that the training being done is "pulling up" and it took him 3 weeks before his muscles were capable of doing this over a distance and that was before any torque was being applied. How much stronger are those pulling up muscles capable of becoming. Why train muscles to apply torque on the upstroke when your other leg is supposed to be applying maximal torque. It makes far more sense to concentrate on applying torque in a sector when both legs are effectively idling.

I don't think it is possible to make those "pulling up" muscles much stronger. The issue isn't strength as those muscles are already very strong as they are involved in doing a sit-up. The problem is aerobic fitness. The need to use that muscle 90 (or much more in the case of a track cyclist) times a minute for several minutes or hours. It takes time to fully develop that muscle just as it takes time for sedentary people to train to do a marathon.

The reason to train those muscle is to be able to add to the work done by the other muscles to increase overall power beyond what can be done without them.

 

[coapman]

I don't think it is possible to make those "pulling up" muscles much stronger. The issue isn't strength as those muscles are already very strong as they are involved in doing a sit-up. The problem is aerobic fitness. The need to use that muscle 90 (or much more in the case of a track cyclist) times a minute for several minutes or hours. It takes time to fully develop that muscle just as it takes time for sedentary people to train to do a marathon.

The reason to train those muscle is to be able to add to the work done by the other muscles to increase overall power beyond what can be done without them.

If they cannot become any stronger, they cannot apply any extra torque, so how could they add to the work done by the other muscles. P Holman also stated that "pulling up" training weakened his downstroke power and he had to do additional non PC training to restore the power in those muscles. As CoachFergie said, Holman's improvement came from his extra interval training time and not from his use of Powercranks. Did he succeed in his objective the following year.

 

[FrankDay]

If they cannot become any stronger, they cannot apply any extra torque, so how could they add to the work done by the other muscles. P Holman also stated that "pulling up" training weakened his downstroke power and he had to do additional non PC training to restore the power in those muscles. As CoachFergie said, Holman's improvement came from his extra interval training time and not from his use of Powercranks. Did he succeed in his objective the following year.

Sure they can. Let's take the capability to do bicep curls as an example. Let's say your biceps have a maximum strength to do one 100 lb curl before they had to rest. But, you have the ability to do 50 per minute with no weight on the bar. Now, if we suddenly put 2 lbs on the bar and you try to do 50 per minute you would not be able to and you would fail before you got to 50. But, if you kept at it you would eventually be able to do 50 per minute with 2 lbs on the bar because this is well below the maximum capability of the muscle from a strength perspective but you have a better adapted muscle from an aerobic point of view. You have trained that muscle to do more work without training it to become physically stronger. All the PowerCranks do of the hip flexors (and hamstrings) is just a little more than what they are doing now, repeated frequently, but well below the maximum strength capability of the muscle. It is no different than training to push harder to develop more power, it is mostly aerobic conditioning not strength conditioning. Holman seemed to concentrate on the pulling up more than most, it seems, but I would bet that as he got better he didn't do much more than simply unweight except when he was thinking about it.

And, I might suggest that I think Holman is a better judge of what made him better (he was there) than either you or Fergie.

 

[CoachFergie]

And, I might suggest that I think Holman is a better judge of what made him better (he was there) than either you or Fergie.

Well not really. If he is an engineer and thinks a Cateye Cyclosimulator is a valid and reliable method of measuring power then I don't think very highly of his opinion. Bit like the MIT grad who doesn't know to calibrate or at least do a zero-offset before conducting an FTP test.

Before I do any testing with a Quarq or SRM I check the calibration. Just is case there is another reason for increased speed beyond an increase in power

 

[coapman]

but I would bet that as he got better he didn't do much more than simply unweight except when he was thinking about it.

So why spend money on expensive PC's and suffer for 9 months when at the end all you've got in return is the unweighting technique. There is also the fact, at a constant speed if you attempt to apply torque during your upstroke, you will lose more in your downstroke, as Holman discovered whenever he pulled up.

 

[FrankDay]

So why spend money on expensive PC's and suffer for 9 months when at the end all you've got in return is the unweighting technique. There is also the fact, at a constant speed if you attempt to apply torque during your upstroke, you will lose more in your downstroke, as Holman discovered whenever he pulled up.

I guess I missed the part where Phil Holman really hated what the cranks did to him.

You might want to look into something called the extension reflex also. It is the reflex by which the harder you pull the foot up the harder you push the other foot down. Useful for when you step on a tack. Pulling up harder doesn't necessarily prevent pushing down hard or even harder with the other leg.

 

[Tapeworm]

I'm just going to leave this here for Frank and coapman:-
http://axiscranks.com/

 

[FrankDay]

I'm just going to leave this here for Frank and coapman:-
http://axiscranks.com/

I had seen that before. Since the iCranks are a done deal I think this has little to offer me. Thanks though.

 

[coapman]

I had seen that before. Since the iCranks are a done deal I think this has little to offer me. Thanks though.

What can iCranks do for your PC pedalling? In that "AXIS CRANK" article, pedalling efficiency means the percentage of tangential force from the total force applied, which is how I also understand it. The graph clearly shows the wasted force being applied by natural pedallers. In my TT technique there is no wasted force. How could PC pedalling improve that "AXIS CRANK" pedalling graph and demonstrate where that 40% power improvement occurs.

 

[FrankDay]

What can iCranks do for your PC pedalling? In that "AXIS CRANK" article, pedalling efficiency means the percentage of tangential force from the total force applied, which is how I also understand it. The graph clearly shows the wasted force being applied by natural pedallers. In my TT technique there is no wasted force.

How do you know if you have never measured it.

How could PC pedalling improve that "AXIS CRANK" pedalling graph and demonstrate where that 40% power improvement occurs.

We will have to wait and see what people can actually do with the information. At the present time it simply has the potential to give the rider information that the rider can hopefully use to make change.

 

[coapman]

How do you know if you have never measured it.
We will have to wait and see what people can actually do with the information. At the present time it simply has the potential to give the rider information that the rider can hopefully use to make change.

Because the force is applied at right angles to the moving crank. If you are not prepared to change or cannot change your technique, how can you learn anything from it. Powercranks do not change technique from the basic natural (circular) style.

 

[FrankDay]

Because the force is applied at right angles to the moving crank. If you are not prepared to change or cannot change your technique, how can you learn anything from it. Powercranks do not change technique from the basic natural (circular) style.

Boy, you must be the only person in the world who can do this. Love to learn how (assuming you can show us you do) except perfectly tangential force application is a lot of wasted effort. That is because a lot of the non tengential force doesn't cause any inefficiencies. All of the forces that come from gravity or inertial effects are non-tangential (except the brief instant when the cranks are parallel to the ground) but because these forces do not come from muscular effort they cannot cause energy inefficiencies. The only non-tangential forces that cause energy inefficiencies are those that come from muscle contractions. But, how to separate them. I guess it can be done theoretically but how to do it in the real world, almost impossible.

This probably why all these efforts to correlate the force dynamic to efficiency fails. If these tests were run in space, in a zero gravity environment, I suspect they would see much greater success. Therefore, a crank like the axis crank that also measures readial loads offers no significant advantage over a crank like the iCranks, that only measure propulsive torque. I think it more useful to put ones time into maximizing propulsive forces rather than trying to minimize non-propulsive forces.

 

[coapman]

except perfectly tangential force application is a lot of wasted effort.-------- Therefore, a crank like the axis crank that also measures readial loads offers no significant advantage over a crank like the iCranks, that only measure propulsive torque.

Perfectly tangential force application is a lot of wasted effort when minimal forces are involved, as in circular or PC pedalling but not when continuous maximal force is being applied. The "axis crank" would be very useful when perfecting the semicircular technique, such as when merging maximal forward and downward forces between 12 and 3 o'c and eliminating all wasted force in that sector.

 

[FrankDay]

Perfectly tangential force application is a lot of wasted effort when minimal forces are involved, as in circular or PC pedalling but not when continuous maximal force is being applied. The "axis crank" would be very useful when perfecting the semicircular technique, such as when merging maximal forward and downward forces between 12 and 3 o'c and eliminating all wasted force in that sector.

Perfectly tangential effort may be a lot of wasted effort even when large forces are involved. let me try again by giving an example. You say you have maximum tangential force between 11 and 1. At 12 o'clock the crank is perfectly perpendicular to the ground to the perfect tangential force would be straight forward. Now, there are two forces working on the pedal. The force of the muscles, which will be mostly forward here if one is contracting the quads and not the glutes. And the force of gravity, which will direct the weight of the leg force to be exactly downward. Together, these forces are not perfectly tangential and they can never be unless the rider also does a force to counter the force of gravity on the leg, unweighting the pedal with the hip flexors at TDC. That effort, necessary to get perfectly tangential force at TDC is completely wasted and inefficient because it involves a muscular effort and that effort does nothing to propel the bicycle (the foot is not moving up so no potential energy is being added here whereas unweighting does do some work in the upstroke because of the adding of potential energy). This same problem exists around the entire circle except it is slightly different at each location. Efficiency should improve if the muscular forces are more tangential. This is essentially impossible to measure and has little to do with what the measured pedal forces direction actually is. If your actual pedal forces are perfectly tangential you are probably pedaling pretty inefficiently.

 

[coapman]

Perfectly tangential effort may be a lot of wasted effort even when large forces are involved. let me try again by giving an example. You say you have maximum tangential force between 11 and 1. At 12 o'clock the crank is perfectly perpendicular to the ground to the perfect tangential force would be straight forward. Now, there are two forces working on the pedal. The force of the muscles, which will be mostly forward here if one is contracting the quads and not the glutes. And the force of gravity, which will direct the weight of the leg force to be exactly downward. Together, these forces are not perfectly tangential and they can never be unless the rider also does a force to counter the force of gravity on the leg, unweighting the pedal with the hip flexors at TDC. That effort, necessary to get perfectly tangential force at TDC is completely wasted and inefficient because it involves a muscular effort and that effort does nothing to propel the bicycle (the foot is not moving up so no potential energy is being added here whereas unweighting does do some work in the upstroke because of the adding of potential energy). This same problem exists around the entire circle except it is slightly different at each location. Efficiency should improve if the muscular forces are more tangential. This is essentially impossible to measure and has little to do with what the measured pedal forces direction actually is. If your actual pedal forces are perfectly tangential you are probably pedaling pretty inefficiently.

What a load of nonsense. When my pedal is at TDC the weight of that leg is resting on the pedal, stabilizing the shoe/foot on the pedal as the maximal force is driven forward from the hip. What prevents the maximal torque that I generate around TDC from propelling the bike forward? Except for unweighting, I am not concerned with what happens around the entire circle, only between 11 and 5 o'c.

 

[FrankDay]

What a load of nonsense. When my pedal is at TDC the weight of that leg is resting on the pedal, stabilizing the shoe/foot on the pedal as the maximal force is driven forward from the hip. What prevents the maximal torque that I generate around TDC from propelling the bike forward? Except for unweighting, I am not concerned with what happens around the entire circle, only between 11 and 5 o'c.

Nothing prevents the maximum force you produce from propelling the bike forward (unless the direction of the force produced is not tangential at which point the effectiveness of that force will be reduced some). However, any instrument measuring the force at the pedal cannot discriminate between that force that comes from your muscles and the force that comes from your resting the foot on the pedal. So a perfectly tangential force application by the muscles is never going to look like this to any instrument trying to measure pedal forces. It will be impossible to ever confirm that our muscle generated forces are "perfectly tangential" or not.

 

[FrankDay]

Hey, while investigating another topic I found that the work done by Burns on the PowerCranks in his Masters Thesis finally got published (link here). Of course, it shows no benefit but, interestingly, it includes the reason why as it showed no difference between the groups in EMG activation. So much for Fergies contention that this is an adequate amount of time or stimulus to make these changes. I stand by my contention that in order to demonstrate that there is no benefit it is also necessary to demonstrate that the stimulus was adequate to make the expected changes in technique. The fact that Fergie declares it to be enough is not good evidence that it is enough.

 

[sciguy]

Hey, while investigating another topic I found that the work done by Burns on the PowerCranks in his Masters Thesis finally got published (link here). Of course, it shows no benefit but, interestingly, it includes the reason why as it showed no difference between the groups in EMG activation. So much for Fergies contention that this is an adequate amount of time or stimulus to make these changes. I stand by my contention that in order to demonstrate that there is no benefit it is also necessary to demonstrate that the stimulus was adequate to make the expected changes in technique. The fact that Fergie declares it to be enough is not good evidence that it is enough.

So let's get this straight, for a product who's use you claim leads typical users to a 40% improvement in FTP power after an appropriate time period they found that after "Five weeks of training with uncoupled cycling cranks had no effect on economy of motion, gross efficiency, muscle recruitment, or VO2max compared with training on normal cranks."

Does the 40% improvement just magically show up just after 90 days have passed? If this training technique is so potent, much better than EPO, why doesn't some significant effect begin to show up almost immediately?

Hugh

 

[coapman]

Of course, it shows no benefit but, interestingly, it includes the reason why as it showed no difference between the groups in EMG activation. So much for Fergies contention that this is an adequate amount of time or stimulus to make these changes. I stand by my contention that in order to demonstrate that there is no benefit it is also necessary to demonstrate that the stimulus was adequate to make the expected changes in technique.

But how can there be any changes when it is the same basic natural pedaling style, a more extreme version of the circular style. There can't be any changes if there is no conscious effort to make those changes. What changes are supposed to occur after 18 months of exclusive PC pedaling. If a PC user does not know about the changes that are supposed to take place, how can he make them. As my semi circular style demonstrates, you don't need special equipment to change and improve the natural pedaling style, it's all in the mind and the inter action between brain and muscles, with the correct objectives changes can take effect from day one.

 

[JayKosta]

The abstract of the Burns article doesn't mention whether the 'trained cyclists' needed to make (or whether they DID make) any adaptation of their pedal technique for the PCs.

Perhaps their existing pedal technique did NOT result in 'de-coupling' of the PC arms when using their regular technique. If that is the case, then PC training would not yield the advertised results (because in that situation the PC would behave like a fixed crank).

I think the greatest potential improvement from use of PC would be for cyclists who do need to train and adapt their pedal technique to prevent PC de-coupling.

Without knowing details about the pre-test pedal technique of the 'trained cyclists' a conclusion can't be drawn about whether the PC would benefit other cyclists.

Jay Kosta
Endwell NY USA

 

[FrankDay]

The abstract of the Burns article doesn't mention whether the 'trained cyclists' needed to make (or whether they DID make) any adaptation of their pedal technique for the PCs.

Perhaps their existing pedal technique did NOT result in 'de-coupling' of the PC arms when using their regular technique. If that is the case, then PC training would not yield the advertised results (because in that situation the PC would behave like a fixed crank).

I think the greatest potential improvement from use of PC would be for cyclists who do need to train and adapt their pedal technique to prevent PC de-coupling.

Without knowing details about the pre-test pedal technique of the 'trained cyclists' a conclusion can't be drawn about whether the PC would benefit other cyclists.

Jay Kosta
Endwell NY USA

About 1 in 1,000 people who get on the PowerCranks are are able to ride them for a substantial period of time without much difficulty. These individuals will probably see little benefit from PC use. When the likelihood is about so small (even in the elite trained cyclist ranks) of running across someone like this I think it quite unlikely that the Burns cohort was filled with this type.

It is a little frustrating to me that few, if any, of these authors comment on the difficulties encountered by the PC group in adapting to the product (they imply they were riding an hour a day on them, just like the control group, from the get go - most experienced PowerCrankers will think back on their own adaption and laugh at that notion. It does make make me wonder what is going on sometimes (did they leave the dual mode cranks locked up?) although our experience says part-time use for 5-6 weeks would be an inadequate stimulus for most people to guarantee statistically significant results being shown in a small cohort, especially for the better trained riders.

 

[CoachFergie]

Hey, while investigating another topic I found that the work done by Burns on the PowerCranks in his Masters Thesis finally got published (link here). Of course, it shows no benefit but, interestingly, it includes the reason why as it showed no difference between the groups in EMG activation. So much for Fergies contention that this is an adequate amount of time or stimulus to make these changes. I stand by my contention that in order to demonstrate that there is no benefit it is also necessary to demonstrate that the stimulus was adequate to make the expected changes in technique. The fact that Fergie declares it to be enough is not good evidence that it is enough.

Never claimed to be the Messiah.

Both Bohm and Fernandez-Pena studies both showed a change in muscle recruitment when using an independent crank. What Burns confirms is the training with a Gimmickcrank does not lead to any long term adaptations that enhance performance. Physiological adaptations to a training stimulus occur in a matter of seconds, minutes and hours and as we see from a variety of studies huge adaptations to a training stimulus (Short Interval Training leading to a 100% improvement in time to exhaustion from 12-18 mins of total training in a 2 week period).

So the Bohm and Fernandez-Pena studies confirm that an independent crank training system changes the training stimulus and application of power around the pedal stroke and their own conclusions plus those of Luttrell, Williams, Sperlich and Burns all show that this training stimulus do not lead to any changes in cycling specific fitness in a time period where a wealth of other studies have shown there is huge potential for the right training stimulus to lead to positive adaptations.

 

[CoachFergie]

It is a little frustrating to me that few, if any, of these authors comment on the difficulties encountered by the PC group in adapting to the product (they imply they were riding an hour a day on them, just like the control group, from the get go - most experienced PowerCrankers will think back on their own adaption and laugh at that notion. It does make make me wonder what is going on sometimes (did they leave the dual mode cranks locked up?) although our experience says part-time use for 5-6 weeks would be an inadequate stimulus for most people to guarantee statistically significant results being shown in a small cohort, especially for the better trained riders.

Yet a variety of training, nutritional, recovery, technical and even psychological studies find rather large performance improvements in a very short time. Face it Frank, your product doesn't work as you claim.