The pedaling technique thread

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coapman said:
What is perfection ?
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For pedaling techique, there isn't a single 'perfect' or 'ideal' style that is the same for everyone.

The 'results' that come from use of a technique are the measure of its quality for an individual.

Those 'results' include:
1) Bike speed
2) Physical endurance
3) Practicality for 'real world' use
4) 'Legality' for sport (or law)

A technique that gives the highest preferred 'blend' of results would be ideal for the individual using the technique.

Jay Kosta
Endwell NY USA
 
Mar 10, 2009
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JayKosta said:
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For pedaling techique, there isn't a single 'perfect' or 'ideal' style that is the same for everyone.

The 'results' that come from use of a technique are the measure of its quality for an individual.

Those 'results' include:
1) Bike speed
2) Physical endurance
3) Practicality for 'real world' use
4) 'Legality' for sport (or law)

A technique that gives the highest preferred 'blend' of results would be ideal for the individual using the technique.

Jay Kosta
Endwell NY USA

Based on the books I have read on pedalling research, the ideal or perfect technique appears to be the technique that would be best in a track pursuit for constant close to maximal high gear power output. From my own experience for acceleration purposes mashing is best and for more relaxed exercise riding circular is best.
 
Mar 10, 2009
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FrankDay said:
Something of interest regarding how position affects pedaling technique.

Influence of different racing positions on mechanical and electromyographic patterns during pedaling

Supports my hypothesis that the more aero one is the harder it is to get the crank over TDC in that the more aero the rider is the more the negatives on the backstroke which must be made up by pushing harder on the downstroke for the same power.
Shorter cranks can improve that situation but this is another reason why a different technique is required for aero riding in time trials. In natural pedalling the knee controls the action, it has to be raised high enough so as to be able to kick the foot forward over TDC, whereas with the TT technique the hip smoothly slides the foot over TDC with the knee in a lower position while generating maximal torque in the process.
 
Sep 23, 2010
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coapman said:
In natural pedalling the knee controls the action, it has to be raised high enough so as to be able to kick the foot forward over TDC, whereas with the TT technique the hip smoothly slides the foot over TDC with the knee in a lower position while generating maximal torque in the process.
I think you might want to rethink that statement. Last time I looked at this the height of the knee over TDC was determined by geometrical considerations mostly determined by the crank length, saddle position, and leg parts lengths (foot orientation might cause a small difference), since the bones are rigid and fixed in length, and not the pedaling technique used.
 
Mar 10, 2009
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FrankDay said:
I think you might want to rethink that statement. Last time I looked at this the height of the knee over TDC was determined by geometrical considerations mostly determined by the crank length, saddle position, and leg parts lengths (foot orientation might cause a small difference), since the bones are rigid and fixed in length, and not the pedaling technique used.

What are your thigh muscles doing at 11 and 12 o'c ?
 
Sep 23, 2010
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coapman said:
What are your thigh muscles doing at 11 and 12 o'c ?
I would guess (since I have never measured their activity directly) that my quads are contracting (I do know that I am applying forward torque at 11, 12 (I have measured it) and the only way that can be done is if the quads are contracting) and most of the others are relaxing. That having been said, I don't see what that (or anything else the muscles are doing or could be doing) has anything to do with how high my knee goes.
 
Mar 10, 2009
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FrankDay said:
I would guess (since I have never measured their activity directly) that my quads are contracting (I do know that I am applying forward torque at 11, 12 (I have measured it) and the only way that can be done is if the quads are contracting) and most of the others are relaxing. That having been said, I don't see what that (or anything else the muscles are doing or could be doing) has anything to do with how high my knee goes.

When does the PC'er stop lifting the rising crank and pedal and can you detect where this man starts his main power stroke when at maximal power output in the last 50 yds on this track.https://www.youtube.com/watch?v=7hh2DcgpnkU
 
coapman said:
When does the PC'er stop lifting the rising crank and pedal ...
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Is there some reason you think a PC'er would be 'forced' or 'inclined' to stop lifting a 'rising pedal'?

I'm sure that precise vertical 'lifting' force on the pedal MIGHT only happen for a small segment of crank rotation.
The actual direction in which force is applied to the pedal is constantly changing around the full rotation. And the amount of force that is directed in a 'lifting' direction is also constantly changing.

My understanding about PC usage is that the requirement to keep the crank engaged is that there be some amount of positive torque being applied. The exact direction in which the force is applied is not critical as long as some positive torque is maintained.

Pedal-based force measurement would be very helpful to understand the true direction and amount of force being applied to the pedals.

Jay Kosta
Endwell NY USA







Jay Kosta
Endwell NY USA
 
Mar 10, 2009
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JayKosta said:
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Is there some reason you think a PC'er would be 'forced' or 'inclined' to stop lifting a 'rising pedal'?

I'm sure that precise vertical 'lifting' force on the pedal MIGHT only happen for a small segment of crank rotation.
The actual direction in which force is applied to the pedal is constantly changing around the full rotation. And the amount of force that is directed in a 'lifting' direction is also constantly changing.

My understanding about PC usage is that the requirement to keep the crank engaged is that there be some amount of positive torque being applied. The exact direction in which the force is applied is not critical as long as some positive torque is maintained.

Pedal-based force measurement would be very helpful to understand the true direction and amount of force being applied to the pedals.

Jay Kosta
Endwell NY USA







Jay Kosta
Endwell NY USA

Actually I think the PC'er would be forced to continue leaving the hip flexor muscles in working mode as the crank moved past 11 o'c and except for the quads with most of the other muscles in a relaxed state between 11 and 12, this will leave the knee in a higher position compared to what it would be if all muscles (arm, upper and lower leg) were in a contracted state and slightly pressing down on the pedal between 11 and 12. As for when Anquetil started his main power stroke, it started simultaneously at 11 as the other leg ended its power stroke at 5, he did not have to wait for his pedal to arrive at 2 o'c before he could start to apply close to maximal torque.
 
Sep 23, 2010
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coapman said:
When does the PC'er stop lifting the rising crank and pedal and can you detect where this man starts his main power stroke when at maximal power output in the last 50 yds on this track.https://www.youtube.com/watch?v=7hh2DcgpnkU
JayKosta said:
--------------------------------------------
Is there some reason you think a PC'er would be 'forced' or 'inclined' to stop lifting a 'rising pedal'?

I'm sure that precise vertical 'lifting' force on the pedal MIGHT only happen for a small segment of crank rotation.
The actual direction in which force is applied to the pedal is constantly changing around the full rotation. And the amount of force that is directed in a 'lifting' direction is also constantly changing.

My understanding about PC usage is that the requirement to keep the crank engaged is that there be some amount of positive torque being applied. The exact direction in which the force is applied is not critical as long as some positive torque is maintained.

Pedal-based force measurement would be very helpful to understand the true direction and amount of force being applied to the pedals.
A
coapman said:
Actually I think the PC'er would be forced to continue leaving the hip flexor muscles in working mode as the crank moved past 11 o'c and except for the quads with most of the other muscles in a relaxed state between 11 and 12, this will leave the knee in a higher position compared to what it would be if all muscles (arm, upper and lower leg) were in a contracted state and slightly pressing down on the pedal between 11 and 12. As for when Anquetil started his main power stroke, it started simultaneously at 11 as the other leg ended its power stroke at 5, he did not have to wait for his pedal to arrive at 2 o'c before he could start to apply close to maximal torque.
Jay Kosta has it right, the only thing the PC's force the user to do is to have some forward torque applied to the pedal. There is no requirement that the torque be the result of any particular muscle usage or direction.

That having been said, I suspect that PC'ers, like regular crank users, demonstrate a wide range of coordination, especially in the beginning when they are working on the transition and their weaknesses. I suspect the new PC user lifts more than is optimal during the backstroke but over time, as the new user becomes more comfortable with the new technique this extra lifting gradually goes away.

My guess as to the optimum pedaling technique that we should be looking for involves minimizing muscle use that ineffectively converts muscle energy cost to work that drives the bicycle. This means that "lifting up" force should essentially be through when the pedal is at 11 o'clock. This is because at 11 o'clock the pedal is mostly moving forward such that forces applied pulling it up do little to drive the bicycle. Those muscles are better off starting the rest phase such that they can more effectively provide power next time around when the pedal is mostly moving upwards. At 11 o'clock, IMHO, the HF's should be at rest and the quads contracting maximally, to drive the pedal forward.

This same principle applies to all the muscles around the entire stroke. For instance, The quads should be relaxed by the time the pedal is at 4:30 or so since that is where the pedal is mostly moving back and quad contraction there tends to move the foot forward (although it also helps drive the femur down). This also makes sense since the quads need to be contracting strongly by 10:30 or so and no muscle should be used for more than half the circle.

There is a lot of nuance to what is a theoretical optimal muscle usage. Most cyclists are just awful in this regards. PowerCranks improve the situation but I suspect there is still a lot of room for improvement if we can figure out how to tease it out. This is evident when one considers that the efficiency of the average cyclist is about 20% (and the best pros get to about 26%) when contractile efficiency of the typical muscle is around 40%.
 
FrankDay said:
There is a lot of nuance to what is a theoretical optimal muscle usage. Most cyclists are just awful in this regards..
How about an "I suspect", "I think" or "I believe" unless you have some excellent evidence of this.



Hugh
 
Sep 23, 2010
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sciguy said:
How about an "I suspect", "I think" or "I believe" unless you have some excellent evidence of this.



Hugh
No, I think "I know" best describes my certainty in this regards. And, I even gave you the "evidence" in the post: "This is evident when one considers that the efficiency of the average cyclist is about 20% (and the best pros get to about 26%) when contractile efficiency of the typical muscle is around 40%. "

From this data alone we can infer a lot.

A skeletal muscle contractile efficiency of about 40% is well established ("40% efficiency of generating ATP from food energy, losses in converting energy from ATP into mechanical work". The vast majority of cyclists have a total cycling efficiency of about 20% (delta efficiency of about 25%). Here is an interesting study comparing delta efficiency of runners and cyclists. Runners have few losses. Cyclists have large losses. Where do the losses occur in cycling. I think it is a pretty easy case to make that some of those losses occur because of muscles contracting when they are mechanically forced to be very inefficient so there is a large energy cost without much output to show for it.

Anyhow, I think it very strange that no cycling researcher has ever tried to quantify where the energy losses occur between the muscle and the chain to account for this drop in efficiency. They simply say they occur. I suspect this is the case that they simply don't know and they don't want to look stupid by hazarding a guess. One of the reasons gasoline engines are so much more powerful and efficient than they were 40 years ago is because of looking for these losses and inefficiencies and seeing how they could be corrected. Cyclists simply continue to ignore this area. Everyone looks smart if everyone agrees to ignore that which they don't know anything about. If we don't understand where the losses are (and which are fixable and which are not) it is not possible to come up with ideas as to how to improve. As a result we are saddled with such profound assessments like "technique doesn't matter, just push harder." I can understand this being a difficult concept for some people to understand but to say that there are no improvements to come from looking at technique is just bizarre to me. And, someone claiming that addressing some of these inefficiencies can result in large improvements is met with derision by those who have never considered the possibility and don't want to put in the work to change what they do now. It is clear that large inefficiencies exist between the muscle and the chain. Why aren't cyclists interested in reducing or eliminating them, if possible?

Edit: I might add this. Most cyclists have a gross cycling efficiency of 20%. A few pros have been measured at 26%. If the average cyclist could simply increase their efficiency from 20% to 26% they would see a 30% jump in power for the same energy expenditure. Understanding why these losses are there and how to correct them should be on every cyclists mind. It isn't.
 
Mar 10, 2009
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FrankDay said:
My guess as to the optimum pedaling technique that we should be looking for involves minimizing muscle use that ineffectively converts muscle energy cost to work that drives the bicycle.
At 11 o'clock, IMHO, the HF's should be at rest and the quads contracting maximally, to drive the pedal forward.
You mean your quads are working equally as hard at 11 for minimal torque as they do around 3 where maximal torque is being applied.
 
Sep 23, 2010
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coapman said:
You mean your quads are working equally as hard at 11 for minimal torque as they do around 3 where maximal torque is being applied.
What is optimum isn't really clear but one cannot look at the total force on the pedals as to what any single muscle is doing. The total force on the pedals is the result of several muscles working at the same time plus gravity.

Discussing your specific question regarding the quad at 11 and 3 here you go, at least a simple analysis. At 11 the femur is up, almost horizontal with the ground. Contracting the quads there will drive the foot forward (and the reactive force drives the femur back with motion stopped by the saddle). Since the pedal is moving mostly forward here it seems obvious that the quad should be contracting fully here for optimum efficiency and power production.

At 3 the story is quite different. The femur is at an angle of about 45? and the lower leg is almost vertical. The direction the pedal is moving is now down.
Contracting the quads will tend to move the foot forward but the reactive force will tend to move the femur back and down. So, there is still some downward pressure on the pedal here, even though the driving force from and equally sized contraction of just this muscle should be smaller than it is near TDC. The reason the forces are so large at 3 have little to do with the quad contraction but have more to do with the contraction of the glutes plus the addition of the weight of the leg added by gravity. Here is a commonly used forced diagram of current typical pedal patterns.

Note that at TDC there are zero propulsive forces, which means the quad is not contracting. Forward forces do not start until 1 o'clock, which indicates where the contraction of the quad starts (it is the only muscle group that can drive the pedal forward, at least at that position). At 3 note that there are still forward forces on the pedals even larger than the magnitude as seen at 1-2, even though the pedal is moving directly down. Forward forces on the pedal are maintained until the pedal is between 4-5 o'clock (indicating when he stops contracting his quads), even though here the pedal is moving substantially backwards. Forward forces after about 2 o'clock do little for the rider and forward forces after 3 o'clock are entirely wasted, and actually work against the rider. Therefore, this rider would be well served starting and ending his quads contraction earlier. The quads don't have to do any more contracting than they are doing now but better timing would result in much better output. This should be obvious to everyone but I am afraid some here still will not be able to see it. The difficulty is not in understanding why this might be better (at least for most people) but in actually learning how to do this.

A similar analysis can be done for each of the muscle groups involved in cycling to see how they can be improved. For instance, note that there is zero downward force on the pedals at 12 o'clock. This means this rider is completely unweighting the pedal, supporting the entirety of the weight of the leg, using the hip flexors. This is a completely wasted effort since the weight of the leg can be entirely supported by the crank at this position. Save that muscle to be used where it can actually help drive the bicycle, like on the back stroke.
 
Mar 10, 2009
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FrankDay said:
What is optimum isn't really clear but one cannot look at the total force on the pedals as to what any single muscle is doing. The total force on the pedals is the result of several muscles working at the same time plus gravity.

Discussing your specific question regarding the quad at 11 and 3 here you go, at least a simple analysis. At 11 the femur is up, almost horizontal with the ground. Contracting the quads there will drive the foot forward (and the reactive force drives the femur back with motion stopped by the saddle). Since the pedal is moving mostly forward here it seems obvious that the quad should be contracting fully here for optimum efficiency and power production.

At 3 the story is quite different. The femur is at an angle of about 45? and the lower leg is almost vertical. The direction the pedal is moving is now down.
Contracting the quads will tend to move the foot forward but the reactive force will tend to move the femur back and down. So, there is still some downward pressure on the pedal here, even though the driving force from and equally sized contraction of just this muscle should be smaller than it is near TDC. The reason the forces are so large at 3 have little to do with the quad contraction but have more to do with the contraction of the glutes plus the addition of the weight of the leg added by gravity. Here is a commonly used forced diagram of current typical pedal patterns.

Note that at TDC there are zero propulsive forces, which means the quad is not contracting. Forward forces do not start until 1 o'clock, which indicates where the contraction of the quad starts (it is the only muscle group that can drive the pedal forward, at least at that position). At 3 note that there are still forward forces on the pedals even larger than the magnitude as seen at 1-2, even though the pedal is moving directly down. Forward forces on the pedal are maintained until the pedal is between 4-5 o'clock (indicating when he stops contracting his quads), even though here the pedal is moving substantially backwards. Forward forces after about 2 o'clock do little for the rider and forward forces after 3 o'clock are entirely wasted, and actually work against the rider. Therefore, this rider would be well served starting and ending his quads contraction earlier. The quads don't have to do any more contracting than they are doing now but better timing would result in much better output. This should be obvious to everyone but I am afraid some here still will not be able to see it. The difficulty is not in understanding why this might be better (at least for most people) but in actually learning how to do this.

A similar analysis can be done for each of the muscle groups involved in cycling to see how they can be improved. For instance, note that there is zero downward force on the pedals at 12 o'clock. This means this rider is completely unweighting the pedal, supporting the entirety of the weight of the leg, using the hip flexors. This is a completely wasted effort since the weight of the leg can be entirely supported by the crank at this position. Save that muscle to be used where it can actually help drive the bicycle, like on the back stroke.
From another forum by a pedalling researcher and bike fitter,
Originally Posted by milkbaby View Post
I don't get it; aren't we constrained to pedaling in circles because the cranks move in a circle?

That's how people get the impression that riding a bike is natural or has no learned skill. The pedal does control the movement, so to most the best pedal stoke looks just like the worst pedal stroke.

The pedals move around in a circle, riders see this and assume they are pushing the pedals around in a circle. Not just the idiots, there was a study at harvard where they mounted strain gauge pedals on a bike on a computrainer. The strain gauges measured force, cadence measured distance, and they made the assumption that people always push in the direction the pedals are moving in, because that's the way they move. They couldn't explain why calculated wattage from the pedals and measured wattage at the rear wheel was different from person to person.

A while back I found out that there are points within the pedal stroke where the body has very little ability to generate torque. I built a machine to test this, but it turns out a number of the power meter companies knew about this all along. Pioneer has what I consider the best training tool going, a power meter that shows force vectors every 30 degrees. The problem is it's a measuring device, it tells the truth. It shows what the rider is really doing at the pedals, and it's insulting to some people if you tell them they don't know how to pedal a bike (I'm the leading expert in insulting people this way). Stages' marketing department is better than Pioneer's, they knew about the dead spots in the pedal stroke, they just don't tell anyone. They have a very high sampling rate, but they round the output so the user never sees points within a single pedal stroke which generate nothing.


As for this concept of a round pedal stroke, a pedal stroke is made up of force vectors (muscles being used to push the pedal in some direction). A vector is made up of two parts, direction and magnitude. A perfect pedal stroke would always have the direction be tangential to the crank arm. You can argue this point if you want, but the efficiency coefficient is SIN(offset angle)... Magnitude is different. I can push 1100 pounds with my glutes, 30 pound with my hip flexors. Saying the magnitude should always be the same means I would need to limit the larger muscle groups to what the smaller ones produce - that's just plain stupid. In fact, when more torque is needed, the smaller muscle groups are shut down in favor of the larger ones.
__________________
 
Sep 23, 2010
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coapman said:
From another forum by a pedalling researcher and bike fitter,
Originally Posted by milkbaby View Post
I will respond to this in parts.
I don't get it; aren't we constrained to pedaling in circles because the cranks move in a circle?
No, only the foot is constrained to move in a circle. Nothing constrains the muscles to do equal work around the circle, what I consider to be "pedaling in circles".
That's how people get the impression that riding a bike is natural or has no learned skill. The pedal does control the movement, so to most the best pedal stoke looks just like the worst pedal stroke.
To most? To everyone. Everyones foot moves in a circle. It is really not possible to know what the muscles are doing by watching this motion.
The pedals move around in a circle, riders see this and assume they are pushing the pedals around in a circle. Not just the idiots, there was a study at harvard where they mounted strain gauge pedals on a bike on a computrainer. The strain gauges measured force, cadence measured distance, and they made the assumption that people always push in the direction the pedals are moving in, because that's the way they move. They couldn't explain why calculated wattage from the pedals and measured wattage at the rear wheel was different from person to person.
Calculated wattage from the pedals differs from the wattage at the wheel only by the bearing losses and chain losses. There could also be a small difference between the two because the speed of the pedals is not constant and so the averaging is somewhat different (one revolution of the pedals is several revolutions (but not an even number) of the wheel.)
A while back I found out that there are points within the pedal stroke where the body has very little ability to generate torque. I built a machine to test this, but it turns out a number of the power meter companies knew about this all along. Pioneer has what I consider the best training tool going, a power meter that shows force vectors every 30 degrees. The problem is it's a measuring device, it tells the truth. It shows what the rider is really doing at the pedals, and it's insulting to some people if you tell them they don't know how to pedal a bike (I'm the leading expert in insulting people this way). Stages' marketing department is better than Pioneer's, they knew about the dead spots in the pedal stroke, they just don't tell anyone. They have a very high sampling rate, but they round the output so the user never sees points within a single pedal stroke which generate nothing.
I am not sure what he is trying to say. He doesn't seem to understand that generating torque is not quite the same as doing work (generating power) when it comes to pedaling.
As for this concept of a round pedal stroke, a pedal stroke is made up of force vectors (muscles being used to push the pedal in some direction). A vector is made up of two parts, direction and magnitude. A perfect pedal stroke would always have the direction be tangential to the crank arm. You can argue this point if you want, but the efficiency coefficient is SIN(offset angle)... Magnitude is different. I can push 1100 pounds with my glutes, 30 pound with my hip flexors. Saying the magnitude should always be the same means I would need to limit the larger muscle groups to what the smaller ones produce - that's just plain stupid. In fact, when more torque is needed, the smaller muscle groups are shut down in favor of the larger ones.
__________________
The highlighted portion is flat out wrong. The reason is much of the force vector seen at the pedal is altered by gravity and centripetal forces. A perfect pedaling pattern would result in pedal forces due to muscular action alone (subtracting the forces due to gravity and centripetal forces that do not supply any power) that is always tangential. The only way we might know what this was is to do this experiment in space. For instance, at TDC and BDC the gravity vector is straight down. Trying to keep the pedal force vector "tangential" here requires eliminating the gravity vector but this requires supporting the weight of the leg with the muscles (rather than letting the pedal do it) which is very wasteful of energy resources. Understanding optimum pedaling technique requires understanding what the muscles are doing and when they are doing it and not what the forces on the pedal look like. This is why I think the Pioneer system will confuse the user more than help them and why the iCranks system (that simply gives resultant tangential torque) is a little better. The iCranks output looks like a circle if the rider is distributing the work equally around the circle, or pedaling in circles. Below is an example of an iCranks screen shot of what it means to be pedaling in near perfect circles IMHO.
 
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FrankDay said:
Edit: I might add this. Most cyclists have a gross cycling efficiency of 20%. A few pros have been measured at 26%. If the average cyclist could simply increase their efficiency from 20% to 26% they would see a 30% jump in power for the same energy expenditure. Understanding why these losses are there and how to correct them should be on every cyclists mind. It isn't.
What testing have you done in this area? If this is central to what can be improved, as a scientist, what have you done to study this topic?
 
Sep 23, 2010
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JamesCun said:
What testing have you done in this area? If this is central to what can be improved, as a scientist, what have you done to study this topic?
First, as a scientist, one must trust the work of other scientists. The fact that muscle contraction work efficiency is around 40% is pretty well established. The fact that the gross efficiency of cyclists ranges from 16 to 26% and averages around 20% is also pretty well established. If it were not I suspect the researchers who hang out here would quickly come and give links to prove me wrong (which they love to do). They have not.

Also, pedaling technique of the average cyclist is also pretty well established.

Therefore, we can take from this data that the average cyclist is losing about half the power that their muscles develop (or can develop) between the muscle and the wheel. Aren't you the least bit interested in where those losses occur and whether some of them might be prevented? As long as this is the case it doesn't matter how much you train, any improvement you see in your muscles only about 50% show up at the wheel.

Now, I have conjectured that most of those losses are due to poor pedaling technique. And, it turns out that I developed a product to train a better technique, to address some of the losses that I see potentially occurring in most people, if not everyone. I did some testing on some volunteers and saw a 40% increase in power in 6-9 months. If we assume chain and bearing losses of 10% this is less than the full potential of a 90% improvement but substantial none-the-less. However, people like you, come here and proclaim that such improvements are impossible without explaining where the halving of the power occurs between the muscle and the wheel and why those losses are not recoverable. Nor do you address the wide range of cycling efficiencies seen in cyclists, surely they all are human and have the same basic skeletal muscle? You just "know" it is impossible because... well because you say it so.

Tell me what "testing" you have done to show that technique doesn't matter? What makes you so smart in this area?
 
Mar 10, 2009
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FrankDay said:
First, as a scientist, one must trust the work of other scientists. The fact that muscle contraction work efficiency is around 40% is pretty well established. The fact that the gross efficiency of cyclists ranges from 16 to 26% and averages around 20% is also pretty well established. If it were not I suspect the researchers who hang out here would quickly come and give links to prove me wrong (which they love to do). They have not.

Also, pedaling technique of the average cyclist is also pretty well established.

Therefore, we can take from this data that the average cyclist is losing about half the power that their muscles develop (or can develop) between the muscle and the wheel. Aren't you the least bit interested in where those losses occur and whether some of them might be prevented? As long as this is the case it doesn't matter how much you train, any improvement you see in your muscles only about 50% show up at the wheel.

Now, I have conjectured that most of those losses are due to poor pedaling technique. And, it turns out that I developed a product to train a better technique, to address some of the losses that I see potentially occurring in most people, if not everyone. I did some testing on some volunteers and saw a 40% increase in power in 6-9 months. If we assume chain and bearing losses of 10% this is less than the full potential of a 90% improvement but substantial none-the-less. However, people like you, come here and proclaim that such improvements are impossible without explaining where the halving of the power occurs between the muscle and the wheel and why those losses are not recoverable. You just "know" it is impossible.

Tell me what "testing" you have done to show that technique doesn't matter? What makes you so smart in this area?
How do PC's improve loss of power between 1 and 5 o'c where most force is applied to pedals.
 
FrankDay said:
when contractile efficiency of the typical muscle is around 40%. "

From this data alone we can infer a lot.

A skeletal muscle contractile efficiency of about 40% is well established ("40% efficiency of generating ATP from food energy, losses in converting energy from ATP into mechanical work".

Frank,

Who other than you says it's pretty well established? You need to go back and read that wiki you've linked especially the following part.

"This low efficiency is the result of about 40% efficiency of generating ATP from food energy, losses in converting energy from ATP into mechanical work inside the muscle, and mechanical losses inside the body."
They're saying that only 40% of the energy from a glucose molecule gets converted into ATP not that 40% of the original energy does muscular work! The sources I've seen then show ~ 68% at maximum of this 40% end up as muscular work. Are you claiming that muscles work at 100% efficiency converting ATP to useful work??????????

Hugh
 
Sep 23, 2010
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sciguy said:
Frank,

Who other than you says it's pretty well established? You need to go back and read that wiki you've linked especially the following part.
LOL. Might I remind you that I went to medical school. That 40% number was part of the basic physiology course in the first year. I would guess that means it is pretty well established. If it has changed I suspect someone like Dr. Coggan will come forward and give evidence to the contrary.
"This low efficiency is the result of about 40% efficiency of generating ATP from food energy, losses in converting energy from ATP into mechanical work inside the muscle, and mechanical losses inside the body."
They're saying that only 40% of the energy from a glucose molecule gets converted into ATP not that 40% of the original energy does muscular work! The sources I've seen then show ~ 68% at maximum of this 40% end up as muscular work. Are you claiming that muscles work at 100% efficiency converting ATP to useful work??????????

Hugh
Well, the 40% is the efficiency of converting energy into work in skeletal muscle. You are reading it wrong. 20% is the overall efficiency of the cyclist, a 50% drop. Where does the drop occur? Remember that earlier study that I linked too showing a substantial difference between the delta efficiency of the runner and the cyclist? I presume they both have the same internal losses such that the difference is most likely external. Where could those be?

It is a simple research question. How do we account for all of the losses between the muscle and the wheel in a cyclist? It is apparently too complicated for the current research community as none of them have asked it. Anyhow, ask and answer that question and you will under stand how to improve the cyclist beyond what can be done with training alone.
 
Mar 18, 2009
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JamesCun said:
What testing have you done in this area? If this is central to what can be improved, as a scientist, what have you done to study this topic?
Just an FYI: Frank was never a scientist, and long ago gave up his medical license.
 
Sep 23, 2010
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acoggan said:
Just an FYI: Frank was never a scientist, and long ago gave up his medical license.
So, let me get this straight.

I make the assertion that skeletal muscle contracts with an energy efficiency of about 40%;
and the average cyclist has an overall energy efficiency of about 20%;
and that no scientist has ever been able to quantitfy where these losses occur between the muscle and the wheel.

And, all you, a published exercise physiologist, can add to the conversation is an ad hominem attack?

You really know how to make a fella feel secure in his argument. Thanks
 

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