Pedalling technique
Max Bridges
Posts: 108
I use 3 different Wattbikes for much of my training. All 3 consistently give left right balance as 54/46 - 53/47 at powers up to approx 85% of Max 20 min power at cadences ranging from 80rpm to 95 rpm.
Given that the resistance is the same for both legs, the rpm is the same for both legs, position is the same, etc etc, there must be a difference in the technique executed by each leg.
The scan shown by the Wattbike shows very different patterns for each leg. My left more powerful leg displays a massive half peanut but my right leg more a nice efficient circle. I assume my left more powerful leg generates more power by pushing harder on the down stroke?
Please note I do not use clipless pedals but when I did the left right balance does not change.
So my question is directed at both proponents of pedalling technique and also the power is power schools of thought.
If one leg generates far more power than the other but at the same resistance and cadence then my more powerful leg must have a superior technique, but why?
Given that the resistance is the same for both legs, the rpm is the same for both legs, position is the same, etc etc, there must be a difference in the technique executed by each leg.
The scan shown by the Wattbike shows very different patterns for each leg. My left more powerful leg displays a massive half peanut but my right leg more a nice efficient circle. I assume my left more powerful leg generates more power by pushing harder on the down stroke?
Please note I do not use clipless pedals but when I did the left right balance does not change.
So my question is directed at both proponents of pedalling technique and also the power is power schools of thought.
If one leg generates far more power than the other but at the same resistance and cadence then my more powerful leg must have a superior technique, but why?
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Comments
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Most people have a L/R imbalance of some degree, so aiming for a perfect 50/50 split is unrealistic, I would have thought. Surely it's more sensible to focus on developing a higher total power output, rather than squeezing an extra 1-2 watts from one of your legs.0
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Imposter wrote:Most people have a L/R imbalance of some degree, so aiming for a perfect 50/50 split is unrealistic, I would have thought. Surely it's more sensible to focus on developing a higher total power output, rather than squeezing an extra 1-2 watts from one of your legs.
I'm purely taking an academic interest in why and how one leg produces so much more power, at 200 watts it is 16 watts more power not just one or two watts. One leg must have a better technique than the other, so there must be something in technique.0 -
When you say "one leg must have a better technique than the other" presumably you mean one leg may have a better biomechanical performance than the other? Accrediting limbs with the ability to act independently from the brain would be a bit of a leap...0
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Imposter wrote:When you say "one leg must have a better technique than the other" presumably you mean one leg may have a better biomechanical performance than the other? Accrediting limbs with the ability to act independently from the brain would be a bit of a leap...
Certainly I'm trying to send the same signals to each leg but my unconscious brain must be getting different feedback from each leg and asking one leg to contribute more power than the other.
My theory is that serious knee and hip injuries to the right leg have caused my brain to protect the injured leg in some way. My weak right leg actually has a larger thigh than my left so the loss of power has nothing to do with loss of muscle. At Max 20 min power there is no imbalance, it even swings to 49/51 sometimes.
But how would you explain how if cadence and resistance is the same my brain manages to make one leg generate more power than the other? My brain must be using a slightly different technique with each leg.0 -
Why can't the imbalance in power be due to differences in, for example, capillarization or mitochondrial development in each leg?"an original thinker… the intellectual heir of Galileo and Einstein… suspicious of orthodoxy - any orthodoxy… He relishes all forms of ontological argument": jane90.0
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BenderRodriguez wrote:Why can't the imbalance in power be due to differences in, for example, capillarization or mitochondrial development in each leg?
I suppose that could be the reason, but as there is no imbalance near or at Max 20 min power would that be the case?
My right leg is slightly more muscled than the left due to many years fencing which tends to cause you to build more muscle on the front leg.0 -
L/R imbalances are normal are they not otherwise we'd all be ambidextrous?0
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I think you may be oversimplifying. There's no reason to think your left leg is superior in either ability or technique just because it gives higher figures during a normal cycle. If it routinely does more work it's reasonable to guess that it will have adapted somewhat but you don't have empirical evidence. To determine this you'd need to test which leg is capable of producing most power. If me and Chris Hoy cycled (not raced) a lap of a velodrome and I went a little faster it wouldn't mean he was the weaker cyclist. It would mean he went slower than me but doesn't tell me what he COULD do if he tried. The results you're seeing could be as simple as a small difference in leg length or a tendency to sit slightly off centre on the saddle. For all you know your right leg is more efficient and has better technique but you're just in the habit of exerting your left more.Max Bridges wrote:Imposter wrote:When you say "one leg must have a better technique than the other" presumably you mean one leg may have a better biomechanical performance than the other? Accrediting limbs with the ability to act independently from the brain would be a bit of a leap...
Certainly I'm trying to send the same signals to each leg but my unconscious brain must be getting different feedback from each leg and asking one leg to contribute more power than the other.
My theory is that serious knee and hip injuries to the right leg have caused my brain to protect the injured leg in some way. My weak right leg actually has a larger thigh than my left so the loss of power has nothing to do with loss of muscle. At Max 20 min power there is no imbalance, it even swings to 49/51 sometimes.
But how would you explain how if cadence and resistance is the same my brain manages to make one leg generate more power than the other? My brain must be using a slightly different technique with each leg.
The fact that you say fencing has produced asymmetry in your legs supports the theory that this could simply be asymmetrical effort not asymmetrical leg ability.
The fact that the balance converges at higher efforts instead of diverging would suggest to me that it's not down to massive leg strength differences. But individual leg max efforts might tell you more. Regardless - does it really matter very much?0 -
Given that Sky have now ditched SRM in favour of the Stages power meter that only measures one leg and then doubles it - I don't think the difference in legs could be that important. If it were - would Sky be on Stages ? Marginal Gains and all that ?0
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Ai_1 wrote:
I think you may be oversimplifying. There's no reason to think your left leg is superior in either ability or technique just because it gives higher figures during a normal cycle. If it routinely does more work it's reasonable to guess that it will have adapted somewhat but you don't have empirical evidence. To determine this you'd need to test which leg is capable of producing most power. If me and Chris Hoy cycled (not raced) a lap of a velodrome and I went a little faster it wouldn't mean he was the weaker cyclist. It would mean he went slower than me but doesn't tell me what he COULD do if he tried. The results you're seeing could be as simple as a small difference in leg length or a tendency to sit slightly off centre on the saddle. For all you know your right leg is more efficient and has better technique but you're just in the habit of exerting your left more.Max Bridges wrote:Imposter wrote:When you say "one leg must have a better technique than the other" presumably you mean one leg may have a better biomechanical performance than the other? Accrediting limbs with the ability to act independently from the brain would be a bit of a leap...
Certainly I'm trying to send the same signals to each leg but my unconscious brain must be getting different feedback from each leg and asking one leg to contribute more power than the other.
My theory is that serious knee and hip injuries to the right leg have caused my brain to protect the injured leg in some way. My weak right leg actually has a larger thigh than my left so the loss of power has nothing to do with loss of muscle. At Max 20 min power there is no imbalance, it even swings to 49/51 sometimes.
But how would you explain how if cadence and resistance is the same my brain manages to make one leg generate more power than the other? My brain must be using a slightly different technique with each leg.
The fact that you say fencing has produced asymmetry in your legs supports the theory that this could simply be asymmetrical effort not asymmetrical leg ability.
The fact that the balance converges at higher efforts instead of diverging would suggest to me that it's not down to massive leg strength differences. But individual leg max efforts might tell you more. Regardless - does it really matter very much?
Yes it does matter, it is not just a slight difference, it is substantial, and the paradox is the more muscled leg produces less power.
It also needs explaining how if the resistance and cadence is the same has more power been generated by one leg than the other? Is one leg pushing harder, or engaging sooner or for longer through the entire pedal stroke, is there a difference in technique? It is the leg which produces the allegedly inefficient peanut which produces the most power. If I were to work at improving my technique as Wattbike advise and I caused my left leg to produce a nice efficient picture like my right I would reduce my power.
This is the paradox, the stomping inefficient leg produces more power than the smooth efficient leg according to Wattbike anyway.0 -
Are you right footed?
Sounds like the strength and activation of your left posterior muscles is below par. If the quads have to work more to compensate, but it's your less co-ordinated leg, then the over-compensation could lead to that leg outputting more power.
I always find it harder to co-ordinate my pedal stroke under less load. The resistance more or less forces better technique.
Under low load i sometimes get a tightness in my right hamstring (righty), that's a sign for me that my left leg isnt working hard enough, and i'll focus on that a little harder to ease the tightness.
edit .. Let's not forget that at the levels of power youre talking about, that your right is working nowhere near its limit, and the muscle mass doesnt really come into it.All the above is just advice .. you can do whatever the f*ck you wana do!
Bike Radar Strava Club
The Northern Ireland Thread0 -
dw300 wrote:Are you right footed?
Sounds like the strength and activation of your left posterior muscles is below par. If the quads have to work more to compensate, but it's your less co-ordinated leg, then the over-compensation could lead to that leg outputting more power.
I always find it harder to co-ordinate my pedal stroke under less load. The resistance more or less forces better technique.
Under low load i sometimes get a tightness in my right hamstring (righty), that's a sign for me that my left leg isnt working hard enough, and i'll focus on that a little harder to ease the tightness.
edit .. Let's not forget that at the levels of power youre talking about, that your right is working nowhere near its limit, and the muscle mass doesnt really come into it.
I'm right footed which is why it was a surprise to discover that is the lazy leg.0 -
It's not a paradox. As I said in my last post there are several perfectly feasible explanations that have nothing to do with what each leg CAN do but rather how they ARE actually used. The fact your right produces less power in these circumstances does not demonstrate that it can't producing more.Max Bridges wrote:Yes it does matter, it is not just a slight difference, it is substantial, and the paradox is the more muscled leg produces less power.
It also needs explaining how if the resistance and cadence is the same has more power been generated by one leg than the other? Is one leg pushing harder, or engaging sooner or for longer through the entire pedal stroke, is there a difference in technique? It is the leg which produces the allegedly inefficient peanut which produces the most power. If I were to work at improving my technique as Wattbike advise and I caused my left leg to produce a nice efficient picture like my right I would reduce my power.
This is the paradox, the stomping inefficient leg produces more power than the smooth efficient leg according to Wattbike anyway.
Efficiency and power are not synonymous. I presume cyclists are typically much less efficient during a sprint than they are while cruising and yet the sprint is where they produce most power. That's not a paradox either. Efficiency is how much of your effort is translated into output. So let me suggest a completely hypothetical scenario to explain how your results could be explained with no paradox whatsoever. (figures are completely fictional).
Left leg:
Total power 140W
Efficiency 80%
Power output to pedals = 112W
Right leg:
Total power 120W
Efficiency 83.5%
Power output to pedals = 100W
Right/Left balance = 53% / 47%
So if this were the case your left leg output is higher while your right leg efficiency is higher and there's no mystery.
Why is your right leg producing less power? I don't know but it could easily be just a small asymmetry in pedalling effort and nothing to do with leg capability.
I'm also skeptical of your assertion that a 53% / 47% imbalance constitutes a substantial imbalance in physiological terms. maybe a physio or anatomist will step in and clarify but this doesn't seem like a massive disparity to me.0 -
Ai_1 wrote:
It's not a paradox. As I said in my last post there are several perfectly feasible explanations that have nothing to do with what each leg CAN do but rather how they ARE actually used. The fact your right produces less power in these circumstances does not demonstrate that it can't producing more.Max Bridges wrote:Yes it does matter, it is not just a slight difference, it is substantial, and the paradox is the more muscled leg produces less power.
It also needs explaining how if the resistance and cadence is the same has more power been generated by one leg than the other? Is one leg pushing harder, or engaging sooner or for longer through the entire pedal stroke, is there a difference in technique? It is the leg which produces the allegedly inefficient peanut which produces the most power. If I were to work at improving my technique as Wattbike advise and I caused my left leg to produce a nice efficient picture like my right I would reduce my power.
This is the paradox, the stomping inefficient leg produces more power than the smooth efficient leg according to Wattbike anyway.
Efficiency and power are not synonymous. I presume cyclists are typically much less efficient during a sprint than they are while cruising and yet the sprint is where they produce most power. That's not a paradox either. Efficiency is how much of your effort is translated into output. So let me suggest a completely hypothetical scenario to explain how your results could be explained with no paradox whatsoever. (figures are completely fictional).
Left leg:
Total power 140W
Efficiency 80%
Power output to pedals = 112W
Right leg:
Total power 120W
Efficiency 83.5%
Power output to pedals = 100W
Right/Left balance = 53% / 47%
So if this were the case your left leg output is higher while your right leg efficiency is higher and there's no mystery.
Why is your right leg producing less power? I don't know but it could easily be just a small asymmetry in pedalling effort and nothing to do with leg capability.
I'm also skeptical of your assertion that a 53% / 47% imbalance constitutes a substantial imbalance in physiological terms. maybe a physio or anatomist will step in and clarify but this doesn't seem like a massive disparity to me.
It is more often 54/46. This is substantial, 8%, so 16 watts at 200 watts. Again, the rpm is the same, the resistance is the same, yet one leg generates more power. Is the more powerful leg using more oxygen? Is it generating more output for the same input? If it is, I could find another 8% more power by improving the right leg's technique.0 -
I believe you are interpreting this incorrectly. Both legs are operating at the same RPM but the resistance is shared and there is nothing forcing the legs to share the load equally. You appear to be thinking of this like an electrical system with two resistances in parallel and assuming the for the same voltage drop across each the currents should also be equal. However this is not an accurate analogy. You can allocate the distribution of the work load between the two legs, whether consciously or subconsciously. The smoothness of your pedal stroke, your comfort and max power may all vary as you do so and it may feel "wrong" but you can do it and are doing it. However in all of your posts you are talking like your legs are autonomous machines and they're doing something wrong.Max Bridges wrote:It is more often 54/46. This is substantial, 8%, so 16 watts at 200 watts. Again, the rpm is the same, the resistance is the same, yet one leg generates more power. Is the more powerful leg using more oxygen? Is it generating more output for the same input? If it is, I could find another 8% more power by improving the right leg's technique.0 -
Ai_1 wrote:
I believe you are interpreting this incorrectly. Both legs are operating at the same RPM but the resistance is shared and there is nothing forcing the legs to share the load equally. You appear to be thinking of this like an electrical system with two resistances in parallel and assuming the for the same voltage drop across each the currents should also be equal. However this is not an accurate analogy. You can allocate the distribution of the work load between the two legs, whether consciously or subconsciously. The smoothness of your pedal stroke, your comfort and max power may all vary as you do so and it may feel "wrong" but you can do it and are doing it. However in all of your posts you are talking like your legs are autonomous machines and they're doing something wrong.Max Bridges wrote:It is more often 54/46. This is substantial, 8%, so 16 watts at 200 watts. Again, the rpm is the same, the resistance is the same, yet one leg generates more power. Is the more powerful leg using more oxygen? Is it generating more output for the same input? If it is, I could find another 8% more power by improving the right leg's technique.
Obviously one leg is generating more power because the Wattbike measures forces on the chain. I'm not interpreting as you suggest far from it.
I am trying to get either a proponent of pedalling technique, or a proponent of power is power, to explain why one leg delivers 8% more power than the other.
Perhaps the injuries have affected timing and coordination? Perhaps I have more fast twitch muscle fibre in the more built up leg?
If, and it is a big if, if, for some reason of technique, one leg can generate 8% more power, are there gains to be made via improving technique?
In my book, 8% less power for the same perceived effort is evidence something is not working properly.0 -
Max Bridges wrote:In my book, 8% less power for the same perceived effort is evidence something is not working properly.
So despite the fact that few - if any - riders can demonstrate a perfect 50/50 balance, you feel you ought to have one. Why?0 -
Look, I do have close to 50/50 at 20 min Max power. What I want isn't the point. W are looking at 54/46 which is 8%.Imposter wrote:Max Bridges wrote:In my book, 8% less power for the same perceived effort is evidence something is not working properly.
So despite the fact that few - if any - riders can demonstrate a perfect 50/50 balance, you feel you ought to have one. Why?
If you have no constructive comment, ignore the thread. You are only trying to derail it by making personal comments. Typical of people who don't like a question they can't answer to start trying to turn the discussion into something personal.
I ask again, why does my left leg generate 8% more power for the same perceived effort?0 -
I'm not trying to derail it, Trev - but you might as well ask why it is that people's faces are not 100% symmetrical, for all the use it will be to you.
Would have been a great question for Gregor Mendel, if he was still alive...0 -
I think you need to be careful when considering such data, as it is not showing you independent force data from each leg, rather it is showing you the combined force data from both legs.Max Bridges wrote:The scan shown by the Wattbike shows very different patterns for each leg. My left more powerful leg displays a massive half peanut but my right leg more a nice efficient circle. I assume my left more powerful leg generates more power by pushing harder on the down stroke?
IOW the peanut shape you describe is showing you the combined forces from both legs for one half of the pedal stroke (i.e. when one or the other crank is forward of the BB). It is not showing the forces isolated to each leg for a full pedal stroke.
Wattbike measures forces downstream of the bottom bracket, and hence cannot make such a distinction of independent leg/crank forces.
Which is why, when you examine pedal forces independent with pedal or crank based gauges, you will often see a different pattern than when you consider the split in the manner that a Wattbike does.0 -
I'm not sure if you haven't read my comments before responding or if you read them but don't understand them. I have given perfectly rational explanations for what you're observing. You have completely disregarded those explanations without any valid reason. I'm sure there are other viable explanations too.Max Bridges wrote:Ai_1 wrote:
I believe you are interpreting this incorrectly. Both legs are operating at the same RPM but the resistance is shared and there is nothing forcing the legs to share the load equally. You appear to be thinking of this like an electrical system with two resistances in parallel and assuming the for the same voltage drop across each the currents should also be equal. However this is not an accurate analogy. You can allocate the distribution of the work load between the two legs, whether consciously or subconsciously. The smoothness of your pedal stroke, your comfort and max power may all vary as you do so and it may feel "wrong" but you can do it and are doing it. However in all of your posts you are talking like your legs are autonomous machines and they're doing something wrong.Max Bridges wrote:It is more often 54/46. This is substantial, 8%, so 16 watts at 200 watts. Again, the rpm is the same, the resistance is the same, yet one leg generates more power. Is the more powerful leg using more oxygen? Is it generating more output for the same input? If it is, I could find another 8% more power by improving the right leg's technique.
Obviously one leg is generating more power because the Wattbike measures forces on the chain. I'm not interpreting as you suggest far from it.
I am trying to get either a proponent of pedalling technique, or a proponent of power is power, to explain why one leg delivers 8% more power than the other.
Perhaps the injuries have affected timing and coordination? Perhaps I have more fast twitch muscle fibre in the more built up leg?
If, and it is a big if, if, for some reason of technique, one leg can generate 8% more power, are there gains to be made via improving technique?
In my book, 8% less power for the same perceived effort is evidence something is not working properly.
Regardless. It seems clear to me that anyone trying to help you on this thread is wasting their time. You don't want the right answer you want one that suits you or that fits your current understanding. If you get one you can be pretty sure it'll be wrong given you don't understand the numbers you are looking at.
As soon as you start saying the numbers are the numbers and no interpretation is required it's clear you're in trouble. You have to understand an experiment to understand the results. Anyone with any technical background should know that.
If this is how you respond to helpful feedback don't expect much more of it.0 -
Alex_Simmons/RST wrote:
I think you need to be careful when considering such data, as it is not showing you independent force data from each leg, rather it is showing you the combined force data from both legs.Max Bridges wrote:The scan shown by the Wattbike shows very different patterns for each leg. My left more powerful leg displays a massive half peanut but my right leg more a nice efficient circle. I assume my left more powerful leg generates more power by pushing harder on the down stroke?
IOW the peanut shape you describe is showing you the combined forces from both legs for one half of the pedal stroke (i.e. when one or the other crank is forward of the BB). It is not showing the forces isolated to each leg for a full pedal stroke.
Wattbike measures forces downstream of the bottom bracket, and hence cannot make such a distinction of independent leg/crank forces.
Which is why, when you examine pedal forces independent with pedal or crank based gauges, you will often see a different pattern than when you consider the split in the manner that a Wattbike does.
Alex, thanks for that. However I got the same when I tested both Garmin Vector and Look Keo Power Pedals, so the imbalance would appear to be real.
Could the imbalance be caused by the left leg being lazy and applying some negative force on the upstroke?0 -
Max Bridges wrote:Alex, thanks for that. However I got the same when I tested both Garmin Vector and Look Keo Power Pedals, so the imbalance would appear to be real.
Strange that you didn't mention that before..?0 -
Ai_1 wrote:
I'm not sure if you haven't read my comments before responding or if you read them but don't understand them. I have given perfectly rational explanations for what you're observing. You have completely disregarded those explanations without any valid reason. I'm sure there are other viable explanations too.Max Bridges wrote:Ai_1 wrote:
I believe you are interpreting this incorrectly. Both legs are operating at the same RPM but the resistance is shared and there is nothing forcing the legs to share the load equally. You appear to be thinking of this like an electrical system with two resistances in parallel and assuming the for the same voltage drop across each the currents should also be equal. However this is not an accurate analogy. You can allocate the distribution of the work load between the two legs, whether consciously or subconsciously. The smoothness of your pedal stroke, your comfort and max power may all vary as you do so and it may feel "wrong" but you can do it and are doing it. However in all of your posts you are talking like your legs are autonomous machines and they're doing something wrong.Max Bridges wrote:It is more often 54/46. This is substantial, 8%, so 16 watts at 200 watts. Again, the rpm is the same, the resistance is the same, yet one leg generates more power. Is the more powerful leg using more oxygen? Is it generating more output for the same input? If it is, I could find another 8% more power by improving the right leg's technique.
Obviously one leg is generating more power because the Wattbike measures forces on the chain. I'm not interpreting as you suggest far from it.
I am trying to get either a proponent of pedalling technique, or a proponent of power is power, to explain why one leg delivers 8% more power than the other.
Perhaps the injuries have affected timing and coordination? Perhaps I have more fast twitch muscle fibre in the more built up leg?
If, and it is a big if, if, for some reason of technique, one leg can generate 8% more power, are there gains to be made via improving technique?
In my book, 8% less power for the same perceived effort is evidence something is not working properly.
Regardless. It seems clear to me that anyone trying to help you on this thread is wasting their time. You don't want the right answer you want one that suits you or that fits your current understanding. If you get one you can be pretty sure it'll be wrong given you don't understand the numbers you are looking at.
As soon as you start saying the numbers are the numbers and no interpretation is required it's clear you're in trouble. You have to understand an experiment to understand the results. Anyone with any technical background should know that.
If this is how you respond to helpful feedback don't expect much more of it.
You seem to have missed that I explained the imbalance does not exist at or close to Max 20 min power or above. Also, I've explained I've had severe injuries to the right leg.
As to your rather personal comments, I'm keeping an open mind as to what the cause of the imbalance might be, and I think you have misunderstood me and the questions I'm asking.0 -
Imposter wrote:Max Bridges wrote:Alex, thanks for that. However I got the same when I tested both Garmin Vector and Look Keo Power Pedals, so the imbalance would appear to be real.
Strange that you didn't mention that before..?
I referred to Wattbike because that is what I'm using currently, I have often mentioned my imbalance in the past on this and other forums.
I wasn't expecting the Wattbike's left right balance data to be questioned, if I was I would have mentioned I got the same results on other systems.0 -
For what it's worth my own feeling is the imbalance is caused by my subconsciously protecting the injuries at lower powers. I also tend to move my foot backwards and forwards on the pedal and constantly change my foot angle to relieve knee discomfort so I may be choosing a less powerful position because it causes less pain.0
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You tested using the pedals on the Wattbike? Well given that asymmetry in left-right power production is normal, I've no doubt your asymmetry is real.Max Bridges wrote:Alex, thanks for that. However I got the same when I tested both Garmin Vector and Look Keo Power Pedals, so the imbalance would appear to be real.
It could, but there are several possible and plausible reasons.Max Bridges wrote:Could the imbalance be caused by the left leg being lazy and applying some negative force on the upstroke?
Therein lies a problem - I don't think these things can tell you a cause, merely report what they measure, and it's important to recognise the differences in what's being measured, especially with downstream measurement as what's reported is a combination of the whole, and not a number generated in isolation.
At this stage, I'd say these force diagrams or power splits represent data, but not necessarily actionable intelligence.
And even if you are looking at numbers generated from independent measurements points, you then need to address the relative accuracy of each side (or at least validate there is no inherit L-R bias, which would only take for a pedal to be installed differently to occur), and finally realise that it's still a connected system. What happens at one crank still impacts what's going on with the other.
Certainly if you are feeling soreness or pain, then perhaps consider changing something with your bike position, or making sure you're not doing more than your body is ready for.
As an example of the difference in how left-right balance data is measured, here's a video by DC Rainmaker showing the left right power balance by same rider using a Quarq and Garmin Vectors.
http://www.youtube.com/watch?v=k0i_jV9ygLI
When pedalling normally, one meter says he's right leg dominant, the other says left leg dominant (forget the data from the single leg drills).
Which is right?
What conclusions would you draw if you only had one or the other?
Would some think they have one issue when looking at one set of numbers but a different issue when looking at the other?0 -
Nope, I didn't miss that I even referred to it as corroborating evidence that what I was suggesting may be true:Max Bridges wrote:Ai_1 wrote:
I'm not sure if you haven't read my comments before responding or if you read them but don't understand them. I have given perfectly rational explanations for what you're observing. You have completely disregarded those explanations without any valid reason. I'm sure there are other viable explanations too.Max Bridges wrote:Ai_1 wrote:
I believe you are interpreting this incorrectly. Both legs are operating at the same RPM but the resistance is shared and there is nothing forcing the legs to share the load equally. You appear to be thinking of this like an electrical system with two resistances in parallel and assuming the for the same voltage drop across each the currents should also be equal. However this is not an accurate analogy. You can allocate the distribution of the work load between the two legs, whether consciously or subconsciously. The smoothness of your pedal stroke, your comfort and max power may all vary as you do so and it may feel "wrong" but you can do it and are doing it. However in all of your posts you are talking like your legs are autonomous machines and they're doing something wrong.Max Bridges wrote:It is more often 54/46. This is substantial, 8%, so 16 watts at 200 watts. Again, the rpm is the same, the resistance is the same, yet one leg generates more power. Is the more powerful leg using more oxygen? Is it generating more output for the same input? If it is, I could find another 8% more power by improving the right leg's technique.
Obviously one leg is generating more power because the Wattbike measures forces on the chain. I'm not interpreting as you suggest far from it.
I am trying to get either a proponent of pedalling technique, or a proponent of power is power, to explain why one leg delivers 8% more power than the other.
Perhaps the injuries have affected timing and coordination? Perhaps I have more fast twitch muscle fibre in the more built up leg?
If, and it is a big if, if, for some reason of technique, one leg can generate 8% more power, are there gains to be made via improving technique?
In my book, 8% less power for the same perceived effort is evidence something is not working properly.
Regardless. It seems clear to me that anyone trying to help you on this thread is wasting their time. You don't want the right answer you want one that suits you or that fits your current understanding. If you get one you can be pretty sure it'll be wrong given you don't understand the numbers you are looking at.
As soon as you start saying the numbers are the numbers and no interpretation is required it's clear you're in trouble. You have to understand an experiment to understand the results. Anyone with any technical background should know that.
If this is how you respond to helpful feedback don't expect much more of it.
You seem to have missed that I explained the imbalance does not exist at or close to Max 20 min power or above. Also, I've explained I've had severe injuries to the right leg.Ai_1 wrote:.....The fact that the balance converges at higher efforts instead of diverging would suggest to me that it's not down to massive leg strength differences. But individual leg max efforts might tell you more......0 -
Alex, the tests were separate, 3 different tests on 3 different days on Garmin Vectors, several weeks apart, I couldn't tell you if the pedals were the same. 3 separate tests on Look Keo several weeks apart, plus 3 more sets of Look Keo I tested myself. I also have used at least 6 different Wattbikes. All have shown the same sort of left right balance, so in my case I am sure we are not looking at something being shown up by faulty installation or vagaries of how different types of power meter work.
However I agree entirely that if you only have one power meter you could be sent on a long wild goose chase. When I first discovered the imbalance I didn't believe it and thought wires must be crossed, it was only after all 3 systems showed the same thing I was prepared to accept it.
I've had knee issues for 40 years, I work around the problem. One thing I have learned is if you set everything up for the benefit of the one bad knee you end up with all sorts of problems with the rest of your body.
Probably what we are seeing is my subconscious brain doing the best it can to protect the knee whilst getting out the power my conscious brain is demanding....0 -
Ai_1 wrote:
Nope, I didn't miss that I even referred to it as corroborating evidence that what I was suggesting may be true:Max Bridges wrote:Ai_1 wrote:
I'm not sure if you haven't read my comments before responding or if you read them but don't understand them. I have given perfectly rational explanations for what you're observing. You have completely disregarded those explanations without any valid reason. I'm sure there are other viable explanations too.Max Bridges wrote:Ai_1 wrote:
I believe you are interpreting this incorrectly. Both legs are operating at the same RPM but the resistance is shared and there is nothing forcing the legs to share the load equally. You appear to be thinking of this like an electrical system with two resistances in parallel and assuming the for the same voltage drop across each the currents should also be equal. However this is not an accurate analogy. You can allocate the distribution of the work load between the two legs, whether consciously or subconsciously. The smoothness of your pedal stroke, your comfort and max power may all vary as you do so and it may feel "wrong" but you can do it and are doing it. However in all of your posts you are talking like your legs are autonomous machines and they're doing something wrong.Max Bridges wrote:It is more often 54/46. This is substantial, 8%, so 16 watts at 200 watts. Again, the rpm is the same, the resistance is the same, yet one leg generates more power. Is the more powerful leg using more oxygen? Is it generating more output for the same input? If it is, I could find another 8% more power by improving the right leg's technique.
Obviously one leg is generating more power because the Wattbike measures forces on the chain. I'm not interpreting as you suggest far from it.
I am trying to get either a proponent of pedalling technique, or a proponent of power is power, to explain why one leg delivers 8% more power than the other.
Perhaps the injuries have affected timing and coordination? Perhaps I have more fast twitch muscle fibre in the more built up leg?
If, and it is a big if, if, for some reason of technique, one leg can generate 8% more power, are there gains to be made via improving technique?
In my book, 8% less power for the same perceived effort is evidence something is not working properly.
Regardless. It seems clear to me that anyone trying to help you on this thread is wasting their time. You don't want the right answer you want one that suits you or that fits your current understanding. If you get one you can be pretty sure it'll be wrong given you don't understand the numbers you are looking at.
As soon as you start saying the numbers are the numbers and no interpretation is required it's clear you're in trouble. You have to understand an experiment to understand the results. Anyone with any technical background should know that.
If this is how you respond to helpful feedback don't expect much more of it.
You seem to have missed that I explained the imbalance does not exist at or close to Max 20 min power or above. Also, I've explained I've had severe injuries to the right leg.Ai_1 wrote:.....The fact that the balance converges at higher efforts instead of diverging would suggest to me that it's not down to massive leg strength differences. But individual leg max efforts might tell you more......
Individual Max efforts are not something I'm prepared to waste time doing as I never ride a bike one legged. I did some one leg drills many years ago and it hurt my back.
I've taken on board your comments, I see your point. Cheers and thanks.
You touched on the fact that although both legs are operating at the same rpm the resistance is shared etc.
I didn't explain myself well, but this is my point, the right leg must be applying torque to the pedal differently. Possibly the only difference is the right leg applies less torque on the down stroke or applies the torque later in the stroke. Perhaps the right leg does not apply as much torque through the whole stroke? We do not know, but whatever is happening be it just lack of pressure applied or lack of smoothness or however you wish to express it, the right leg delivers less power.
So the question remains, pedalling technique affects power, by studying imbalance we might find how technique affects power and work on techniques that generate more sustainable power.
If technique is no more than just pushing harder on the down stroke that is in itself a technique.
I'm not sold on pedalling technique, I'm merely keeping an open mind. Studying imbalance in power output might give us clues.0
This discussion has been closed.
