The pedaling technique thread

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Sep 23, 2010
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CoachFergie said:
Classic.

Both Bohm and Fernandez-Pena showed that the experimental group developed a different pedalling technique.
But, they did not do anything beyond measuring technique changed. They did not also measure any performance metrics so nothing can be surmised from these studies other than it is possible to change technique.
Gibala compared a group performing 12-16mins of Short Interval Training over a 2 week period and saw a 100% increase in performance in a test to exhaustion.
Gibala's work http://www.ncbi.nlm.nih.gov/pubmed/16825308 has essentially nothing to do with racing performance as it was done in "active" men. Further, all it did was show two methods resulted in equivalent results. So, you fail in your effort to address the question I asked. ("Point me to a single study done by independent researchers that has been subsequently independently confirmed showing significant improvement in any of the areas mentioned above compared to alternatives")
Does that mean with 10,000 hours of SIT one could expect a 5 Million percent improvement in performance:D
No.
 
Apr 21, 2009
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FrankDay said:
But, they did not do anything beyond measuring technique changed. They did not also measure any performance metrics so nothing can be surmised from these studies other than it is possible to change technique.
Well apart from...

Bohm said:
We observed no
significant statistical difference for peak power (PO]

Guess that is what happens when you cherry pick the research out there to support your cognitive bias.

Gibala's work http://www.ncbi.nlm.nih.gov/pubmed/16825308 has essentially nothing to do with racing performance as it was done in "active" men.
But you were the one claiming we shouldn't use elite subjects because the room for improvement is so small. You also asked for a study showing an increase in performance so I gave you one, of many, if we have a month or three I can keep listing all the studies that show an increase in performance.

But but but, based on the 100% improvement in performance from 12min of training over the 10,000 hours you claim it takes to perfect any technique that should be a realistic outcome:p
 
Sep 23, 2010
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CoachFergie said:
Well apart from...



Guess that is what happens when you cherry pick the research out there to support your cognitive bias.
My bad. I had forgotten that Bohm did that. Anyhow, all that demonstrates is what we say. We say it takes about 4-6 weeks for people to get back to where they were before and Bohm's study lasted 5 weeks. That is what almost everyone experiences. That is what Bohm found. However Bohm says nothing about what would occur with further training, which is our contention that this is where the benefits start. You seem to think this study definitive.
But you were the one claiming we shouldn't use elite subjects because the room for improvement is so small. You also asked for a study showing an increase in performance so I gave you one, of many, if we have a month or three I can keep listing all the studies that show an increase in performance.
No, I didn't ask for a study that would look for an increase in performance. I asked for a study that would show an increase in performance compared to the alternative. Yours showed equal performance improvement using two different techniques. However, the study was not looking at already trained individuals so I think it unlikely that well-trained individuals are going to see 100% improvement. Why don't you find some studies that deal with scenarios that the average person who hangs out here would find compelling rather than a "I found a gotcha study because I could".
But but but, based on the 100% improvement in performance from 12min of training over the 10,000 hours you claim it takes to perfect any technique that should be a realistic outcome:p
No, it seems only you would try to draw such a conclusion from this study. Puts most of your arguments into perspective.
 
Apr 21, 2009
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FrankDay said:
My bad. I had forgotten that Bohm did that.
You're forgiven, there are so many studies now showing no improvement in performance using independent cranks that it is hard to keep track. For some.

However Bohm says nothing about what would occur with further training, which is our contention that this is where the benefits start.
What way does the learning curve slope?

http://forum.cyclingnews.com/showthread.php?p=1147837&highlight=weeks#post1147837

A 10 week study.

You seem to think this study definitive.
Not definitive but quite a clear pattern is forming.

No, I didn't ask for a study that would look for an increase in performance. I asked for a study that would show an increase in performance compared to the alternative. Yours showed equal performance improvement using two different techniques. However, the study was not looking at already trained individuals so I think it unlikely that well-trained individuals are going to see 100% improvement.
Well duh. You might also want to consider the type of test used and compare that to the changes in performance one sees compared to a self paced time trial.

Why don't you find some studies that deal with scenarios that the average person who hangs out here would find compelling rather than a "I found a gotcha study because I could".
Most people who hang out here will employ some form of short interval training as they prepare for goal events. So the Gibala study has some relevance even if you would not expect such a dramatic improvement in elite athletes or using a time trial rather than a test to exhaustion.

Steptoe, in 1999, performed the following study comparing several different interval protocols and their influence on performance....

Steptoe etal said:
Effects of different interval-training programs on cycling time-trial performance. Med. Sci. Sports Exerc., Vol. 31, No. 5, pp.
736-741, 1999.

Purpose: We have investigated the effect of varying the intensity of interval training on 40-km time-trial performance in 20 male
endurance cyclists (peak oxygen uptake 4.8 ± 0.6 L·min-1, mean ± SD).

Methods: Cyclists performed a 25-kJ sprint test, an incremental test to determine peak aerobic power (PP) and a simulated 40-km
time-trial on a Kingcycle ergometer. They were then randomly assigned to one of five types of interval-training session: 12 × 30 s
at 175% PP, 12 × 60 s at 100% PP, 12 × 2 min at 90% PP, 8 × 4 min at 85% PP, or 4 × 8 min at 80% PP. Cyclists completed 6
sessions over 3 wk, in addition to their usual aerobic base training. All laboratory tests were then repeated.

Results: Performances in the time trial were highly reliable when controlled for training effects (coefficient of variation = 1.1%).
The percent improvement in the time trial was modeled as a polynomial function of the rank order of the intensity of the training
intervals, a procedure validated by simulation. The cubic trend was strong and statistically significant (overall correlation = 0.70,
P = 0.005) and predicted greatest enhancement for the intervals performed at 85% PP (2.8%, 95%CI = 4.3-1.3%) and at 175% PP
(2.4%, 95%CI = 4.0-0.7%). Intervals performed at 100% PP and 80% PP did not produce statistically significant enhancements
of performance. Quadratic and linear trends were weak or insubstantial.

Conclusions: Interval training with work bouts close to race-pace enhance 1-h endurance performance]
 
Sep 23, 2010
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CoachFergie said:
The cubic trend was strong and statistically significant (overall correlation = 0.70,
P = 0.005) and predicted greatest enhancement for the intervals performed at 85% PP (2.8%, 95%CI = 4.3-1.3%) and at 175% PP
(2.4%, 95%CI = 4.0-0.7%). Intervals performed at 100% PP and 80% PP did not produce statistically significant enhancements
of performance.
Don't you find it the least bit strange that intervals at 85% and 175% showed improvement but intervals at 80% and 100% showed no improvement? Just exactly what mechanism or mechanisms might explain this?
 
Apr 21, 2009
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FrankDay said:
Don't you find it the least bit strange that intervals at 85% and 175% showed improvement but intervals at 80% and 100% showed no improvement? Just exactly what mechanism or mechanisms might explain this?
Totally!

Between 80, 100 and 175% is understandable. But 80 and 85% is a little odd. Different metabolic pathways and possibly differences in recovery from each particular type of effort leading to different adaptations.
 
Sep 23, 2010
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Got a call from a customer yesterday who is getting ready for IM Arizona (in about 1 month) and had a lot of questions. What he needed really was a lot of reassurance he was on the right track but he was asking a lot of questions.

He has been training on PowerCranks for 2 years and has been listening to the crank length debate seriously and has seriously experimented with a lot of different crank lengths. He has been to the wind tunnel and has been told by two different big name fitters two different crank lengths would be "best" for him. He is 5'11" and one told him 165mm cranks and the other told him 155mm cranks. However, his experimenting is telling him 145 is the best for him. He sees no difference in power between any of these lengths but he cannot sustain these powers in the aero position for hours with the longer crank lengths. When he goes longer than 145 he just doesn't like it. But, there is another issue that is causing me to post this in the pedaling technique thread. He sees a power difference between riding on PowerCranks and regular cranks and the PowerCranks results in higher power. I think this is probably because his cranks are still a little long for him, making it too difficult for him to get the cranks over the top so he tends to revert back to partially pushing the foot over the top, when the cranks allow it, causing a small drop in power. I suspect this will get worse as he begins to get tired. Can anyone come up with another reasonable explanation for this power difference between independent and fixed cranks?

Anyhow, I made three suggestions to him. 1. That he stop worrying about his crank length choice as it was clear to me that he had done the work to determine that 145 was the best crank length for him at this time, at least amongst the crank lengths he had tried, and there wasn't enough time to try shorter crank lengths (and, unfortunately, his model PowerCranks won't let him test shorter than 145). 2. That he consider racing on the PowerCranks because he is somewhat more efficient and powerful with them and he has the base to do this distance on them and do well. 3. That if he decided to race on fixed cranks that he use a length about 5 mm shorter than what he is using now as this is not enough be be noticeable in feel but might be enough to help him keep his technique and power up.

Would you have advised him differently? (And, Fergie, we all know you would advise him to get rid of the gimmickcranks).
 
Can't you just lend him some more highly adjustable Powercranks for the next month?
Looks like a win win for both of you when he is the top Age grouper while at the same time rides Powercranks;)

Hugh
 
Sep 23, 2010
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sciguy said:
Can't you just lend him some more highly adjustable Powercranks for the next month?
Looks like a win win for both of you when he is the top Age grouper while at the same time rides Powercranks;)

Hugh
I guess we could but, imo, there isn't enough time and then, assuming he wanted to race fixed cranks, he would need additional time to find and get those also. Sometimes one just has to accept "good enough." There is always next year.
 
Apr 21, 2009
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FrankDay said:
Would you have advised him differently? (And, Fergie, we all know you would advise him to get rid of the gimmickcranks).
Would have advised him and his coach to evaluate the available literature and make an educated decision. Would be keen to see what process either big name fitter used to come to their conclusions. Judging by some fit systems it would appear that gimmickranks.com is not the only source of cycling equipment and technique misinformation out there.
 
Mar 10, 2009
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FrankDay said:
But, there is another issue that is causing me to post this in the pedaling technique thread. He sees a power difference between riding on PowerCranks and regular cranks and the PowerCranks results in higher power. I think this is probably because his cranks are still a little long for him, making it too difficult for him to get the cranks over the top so he tends to revert back to partially pushing the foot over the top, when the cranks allow it, causing a small drop in power. I suspect this will get worse as he begins to get tired. Can anyone come up with another reasonable explanation for this power difference between independent and fixed cranks?

He is not unweighting when using the fixed cranks, Powercranks force him to do it. That is why it is better to use your brain instead of equipment if you want to improve your technique.
 
Sep 23, 2010
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blutto said:
....hmmm....very interesting.....will it cause this thread to go nuclear or will it finally bring thread peace ?....

....does anyone have an idea of cost ?....

Cheers
My guess is "nuclear". The luddites will hold out as long as possible, until there is scientific proof. (Which for them will never occur).

Did you notice that when he was riding at low power he managed to achieve that more by increasing the forces on the back stroke rather than by pushing less hard. And, when he was at high power he dramatically decreased his back forces on the back stroke, more than he increased his pushing forces proportionally. As this data becomes common place I think it will soon be clear that generating power is much much more than "just pushing harder". I can hardly wait.

Once we (the mass of cyclists) understand this I wonder how easy it will be for people to change their technique by just thinking about it or by looking at the output? Or, if there might be another tool to help them to do so? LOL
 
Jul 4, 2009
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FrankDay said:
Did you notice that when he was riding at low power he managed to achieve that more by increasing the forces on the back stroke rather than by pushing less hard. And, when he was at high power he dramatically decreased his back forces on the back stroke, more than he increased his pushing forces proportionally. As this data becomes common place I think it will soon be clear that generating power is much much more than "just pushing harder". I can hardly wait.
....yeah that was most interesting wasn't it.... waiting with bated breath to see more results from the esteemed Dr. Cheung....

Cheers
 
FrankDay said:
My guess is "nuclear". The luddites will hold out as long as possible, until there is scientific proof. (Which for them will never occur).

Did you notice that when he was riding at low power he managed to achieve that more by increasing the forces on the back stroke rather than by pushing less hard. And, when he was at high power he dramatically decreased his back forces on the back stroke, more than he increased his pushing forces proportionally. As this data becomes common place I think it will soon be clear that generating power is much much more than "just pushing harder". I can hardly wait.

Once we (the mass of cyclists) understand this I wonder how easy it will be for people to change their technique by just thinking about it or by looking at the output? Or, if there might be another tool to help them to do so? LOL
All this shows is that the rider in question has an imbalance between left and right legs, whether this is something that can be fixed by shims, working with a physiotherapist or simply by specific gym work remains to be seen.

Not a deal breaking feature in a PM but could be useful in a few different circumstances (eg: post crash/injury/operation)
 
blutto said:
....hmmm....very interesting.....will it cause this thread to go nuclear or will it finally bring thread peace ?....

....does anyone have an idea of cost ?....

Cheers
DCrainmaker is testing one right now and mentioned that he thought the basic power meter without fancy head unit was ~ $1600 US. Of course it's the fancy head unit that allows the pedaling vector analysis. If/when someone creates a nice shareware app for smart phones to work with these that would make them pretty darn cost competitive with other units.

http://forum.slowtwitch.com/cgi-bin/gforum.cgi?post=4912342#4912342

After hearing feedback from a number of Garmin Vector users, I wasn't very surprised to hear another report of significant pedaling asymmetry.

My prediction is that Frank will be surprised at how asymmetrically many of the folks who ride Powercranks actually pedal. We will soon find that "just getting them around the circle" does not ensure symmetric power application.

Hugh
 
Jul 4, 2009
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....when I brought this up with a local bike owner, who btw is an excellent fitter, his response pretty well mirrored your prediction....

...yup, as I said up-thread gonna be quite interesting to see how this plays out....wonder when Dr. Cheung will have some more results ? ....that article was a nice appetizer but love to have something with a bit more "weight" before committing the fundage....

Cheers
 
Mar 10, 2009
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FrankDay said:
My guess is "nuclear". The luddites will hold out as long as possible, until there is scientific proof. (Which for them will never occur).

Did you notice that when he was riding at low power he managed to achieve that more by increasing the forces on the back stroke rather than by pushing less hard. And, when he was at high power he dramatically decreased his back forces on the back stroke, more than he increased his pushing forces proportionally. As this data becomes common place I think it will soon be clear that generating power is much much more than "just pushing harder". I can hardly wait.

Once we (the mass of cyclists) understand this I wonder how easy it will be for people to change their technique by just thinking about it or by looking at the output? Or, if there might be another tool to help them to do so? LOL

It's a pity this was not done by using the same power and only varying the gearing or cadence. What is very noticeable on all these graphs is the amount of wasted or non tangential force that is being applied from 5 to 6 o'c and even after 6 which can only go to ground and add to rolling resistance. The ideal technique cuts off all force application at 5 and transfers the momentum of that downward foot to the other leg at 11. It is also noticeable in all cases that force being applied in the effective down stroke has most tangential effect at 2 o'c where force is much weaker than that applied at 3 and 4 o'c, reducing the efficiency of the pedalling. With the ideal technique effective force application begins at 11 and is both maximal and fully tangential from 12 to 2.30 o'c. The reduction in negative torque in the upstroke when greatest power is being applied, I believe is due to the rider using the weight of that rising leg for additional resistance to his downward force. As for the imbalance between legs, this can be easily corrected by the simple concentration technique which changes leading power leg every few strokes.
 

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