The pedaling technique thread

[FrankDay]

This means you are applying 90% of 3 o'c torque when cranks are in the 12/6 position.

Yes

Do you apply torque around 9 o'c.

Hardly any except when I am thinking about it and trying to during short bursts of power

What prevents other circular pedalers from applying the torque you are applying.

Nothing except, perhaps, they have not trained themselves as intensively in this method as I have.

 

[coapman]

Yes

Like your special expensive equipment which cannot do what it says on the tin, this is impossible.

 

[FrankDay]

Like your special expensive equipment which cannot do what it says on the tin, this is impossible.

what is impossible?

 

[coapman]

what is impossible?

Muscles which up to now are only capable of scraping something off your shoe are suddenly able to apply up to 60% of the maximal torque that can be applied at 3 o'c. Apart from cycling can you give me another example of where these same muscles are used generating the same power.

 

[sciguy]

Edit: I have recalculated these numbers. It turns out my 6 o'clock numbers are probably closer to 50-60% of my 3 o'clock numbers. Here is how I calculate this. I ride with a SpinScan usually between 90 and 95.

Frank,

What sort of wattage and duration are doing during these rides with Spin Scan between 90 and 95?

Hugh

 

[FrankDay]

Muscles which up to now are only capable of scraping something off your shoe are suddenly able to apply up to 60% of the maximal torque that can be applied at 3 o'c. Apart from cycling can you give me another example of where these same muscles are used generating the same power.

Where did I say that I was applying up to 60% of the "maximal force that can be applied" at 3 o'clock at 6 o'clock? Forces on bicycle pedals are small compared to the maximum capability of the muscles. It has to be that way when one is repeating that force 70-100 times a minute for hours on end.

Anyhow, the math doesn't lie. The spinscan number is what it is. Make your assumptions and then the pedal forces follow.

 

[FrankDay]

Frank,

What sort of wattage and duration are doing during these rides with Spin Scan between 90 and 95?

Hugh

I don't spend a lot of time on training on the Velotron so I can't tell you what I am doing after 3 hours. But, if I am PowerCranks I doubt it changes much because I am forced to be at a minimally smooth technique. Most of the time on the Velotron currently, for me, is for demonstrating and comparing. Right now I am trying to figure out a calibration factor for the iCranks as we change crank length so I am riding, perhaps, 2-5 minutes at a time at power between 100-200 watts.

In the past I have seen that 90+ above 300 watts for reasonable periods. Being closer to 70 than 65 years old means I don't hold those higher powers very long anymore.

I don't want to imply that I never see lower, more "normal" numbers, but when cruising along comfortably it is unusual that I am much below 90 and I see 95 pretty often. The highest spinscan number I have ever seen is 98.

 

[coapman]

Where did I say that I was applying up to 60% of the "maximal force that can be applied" at 3 o'clock at 6 o'clock? Forces on bicycle pedals are small compared to the maximum capability of the muscles. It has to be that way when one is repeating that force 70-100 times a minute for hours on end.

Anyhow, the math doesn't lie. The spinscan number is what it is. Make your assumptions and then the pedal forces follow.

Spinscan numbers are worthless, you can increase your numbers by reducing your peak torque. Can you give an honest estimate of the torque you believe you can apply at 6 o'c when riding at max power output in a flat 10 mile TT and using a gear of 52/12 or 53/12. ( % of torque at 3 o'c)

 

[FrankDay]

Frank,

What sort of wattage and duration are doing during these rides with Spin Scan between 90 and 95?

Hugh

One more thing. It really shouldn't matter except at the extremes. Kautz, et al. (The pedaling technique of endurance cyclists: changes with increasing workload at a constant cadence.) demonstrated that as cyclists increase workload that they change from doing not completely unweighting on the backstroke to completely unweighting on the backstroke. They both push harder and pull harder but change little over the top and bottom. This would result in a reduced spinscan number.

It would seem reasonable that even though I completely unweight at low loads I also would tend to change similarly. The increase in positive work on the back would add to the 3 and 6 total torque and change lower the ratio of the average torque to the peak torque seen by the spinscan algorithm. Remember, spinscan is not an absolute measure of pedaling technique but is only a measure of smoothness. Smoothness is related to technique but there are many different ways to attain the same smoothness. If Coapman can do what he actually says he does (maximum torque sustained around 180º with the two legs alternating) he also would see a spinscan of near 100 even though he would be pedaling totally differently than me who spreads the pedal forces out over as much of the circle as I can. I doubt he can do that but it, I guess, is theoretically possible.

 

[coapman]

Remember, spinscan is not an absolute measure of pedaling technique but is only a measure of smoothness.

You have not replied to my last question ?

 

[sciguy]

I don't spend a lot of time on training on the Velotron so I can't tell you what I am doing after 3 hours.

OK then what sorts of numbers after say an hour at 90+% of your FTP then? Has the spin scan progressively increased, decreased or stayed the same from the beginning of your session?

Thanks,

Hugh

 

[FrankDay]

OK then what sorts of numbers after say an hour at 90+% of your FTP then? Has the spin scan progressively increased, decreased or stayed the same from the beginning of your session?

Thanks,

Hugh

I don't do those kinds of workouts anymore so I don't know what happens. My guess is form would deteriorate somewhat and the weakest link muscles would be the ones to deteriorate the most. If deterioration occurred mostly in the 3 or 9 o'clock quadrants spin scan number might actually increase. If it deteriorated in the 6 or 12 o'clock quadrants it should decrease. What happens to your spinscan after an hour at 90% FTP?

 

[sciguy]

I don't do those kinds of workouts anymore so I don't know what happens. My guess is form would deteriorate somewhat and the weakest link muscles would be the ones to deteriorate the most. If deterioration occurred mostly in the 3 or 9 o'clock quadrants spin scan number might actually increase. If it deteriorated in the 6 or 12 o'clock quadrants it should decrease. What happens to your spinscan after an hour at 90% FTP?

When last I looked and that was several years ago, it stayed a very consistent ~ 75 throughout an hour or two hours. While experimenting with pedaling technique it didn't take too long to notice that higher spin scan numbers yielded less power and ultimately less endurance.

YMMV,

Hugh

 

[FrankDay]

When last I looked and that was several years ago, it stayed a very consistent ~ 75 throughout an hour or two hours. While experimenting with pedaling technique it didn't take too long to notice that higher spin scan numbers yielded less power and ultimately less endurance.

YMMV,

Hugh

I suspect that is because the muscles necessary to achieve better spinscan numbers were not up to the endurance necessary to maintain the effort for long OR the only way you could increase your spinscan was to push less hard, or some combination.

Anyhow, the iCranks people have just upgraded their software and it now has a nice feature, they have included a box to show how much power is being lost on each revolution of the cranks. See below.

This image shows a lot of what we have been talking about. Notice the right leg is much weaker than the left on both pushing and pulling. A normal power meter that combines the two cranks and then determines balance by looking at the two downstrokes would underestimate the imbalance between these two legs by a lot.

Next, at this point in time, the rider is losing over 10% of his positive propulsive efforts from the negative wattage on the upstroke (156 watts positive, 18 watts negative, 138 watts total).

Next, notice the size of the power at 6 o'clock compared to 12, it is much larger than the 12 o'clock number. I think for this rider, the biggest gains will come from working on improving the forces across the top (without changing anything else) and, of course, improving the right leg to be the equal of the left.

I don't know how anyone could look at this data and say technique doesn't matter but, of course, some will.

Anyhow, this software is available for download by anyone. Go to http://www.icranks.com then to Technical Information then download the installer, follow the instructions to save it. There are two examples you can open and see. Example 1 is probably a PowerCranker because he has very few negatives. Example 2 is probably not, because there are a lot of negatives and he keeps trying to fix them but can't sustain it.

 

[CoachFergie]

I suspect that is because the muscles necessary to achieve better spinscan numbers were not up to the endurance necessary to maintain the effort for long OR the only way you could increase your spinscan was to push less hard, or some combination.

Seeing you are demanding scientific evidence about the use of power meters; where is the evidence behind the use of Spin Scan?

Anyhow, the iCranks people have just upgraded their software and it now has a nice feature, they have included a box to show how much power is being lost on each revolution of the cranks. See below.

Will await scientific validation of this.

This image shows a lot of what we have been talking about. Notice the right leg is much weaker than the left on both pushing and pulling. A normal power meter that combines the two cranks and then determines balance by looking at the two downstrokes would underestimate the imbalance between these two legs by a lot.

We will await scientific validation that this actually matters. An extensive review of the cycling related injury literature did not suggest that an imbalance between legs was a major cause of acute issues. Main factors where saddle too high or low, cadence too high or low and too rapid a progression in riding intensity or volume.

I don't know how anyone could look at this data and say technique doesn't matter but, of course, some will.

We await testing to show if these differences have a significant effect on performance.

 

[FrankDay]

We await testing to show if these differences have a significant effect on performance.

Wait away. And, in the meantime keep on using those power meters that have never been shown to have a significant effect on performance.

 

[CoachFergie]

Some most amusing claims being made on the iCrank site...

What do we mean by adding SYNERGY?

Synergy is defined as a combination of efforts being more effective than what the isolated use of the efforts can do by themselves. iCranks combine endurance training, specialized muscle training with additional technique feedback training (something never available before) into one training tool so these all occur all at the same time. The result is usually a lot more benefit coming from the time spent training.

*Specialized muscle training. What does that even mean? In a race on normal cranks you will only pedal one way. Fernandez-Pena showed that any changes to pedalling technique will lost rapidly when you go back to riding normal cranks.

*Technique feedback training. No validation or testing of Spinscan or Wattbike to show that they measure what they claim or that this type of feedback has an actual effect on performance. A marketing claim at best.

Beyond power and speed improvements, iCranks do much more including helping runners develop better form and avoid injury (the coordination required to use iCranks is closely related to optimum running coordination), helping the injured rehabilitate faster and better (use involves zero impact), and helping the injury prone to avoid injury (through better coordination, muscle balance, and reduced joint impact) while maintaining training intensity.

Unproven.

When compared to traditional training methods, iCranks, when properly integrated into the training routine, allow most athletes to achieve much more than was ever possible before using “normal” training techniques.

Very bold statement for a new product. Is this like the product testing performed on uncoupled cranks that you claim you lost Frank? How many test subjects were used to make such a claim?

iCranks are, simply, independent bicycle cranks that replace the regular cranks found on a typical bicycle or exercise machine. Independent means one leg cannot help the other in making the pedals go around and in order to pedal the bike one cannot simply relax on the back stroke but must actively raise the pedal using your hip flexor and hamstring muscles (those generally undertrained muscles mentioned above).

See the Powercrank thread to see that training in this fashion does not lead to any change in cycling performance in studies from 5-10 weeks.

This simple change ensures that your leg muscles will become balanced (both right/left and fore/aft) and that you will be training additional muscles with a coordination important to overall well-being and superior athletic performance. They have been described as plyometrics without the impact or injury risk.

Clearly does not understand what Plyometrics are.

 

[CoachFergie]

Wait away. And, in the meantime keep on using those power meters that have never been shown to have a significant effect on performance.

I totally concur Frank. NOTHING, NADA, ZIPPO effect on performance!

 

[CoachFergie]

More iCrank hype...

CYCLISTS

PowerCranks train cyclists to pedal in a more efficient and more powerful fashion, being used by a long list of World, Olympic, and TDF champions. But, the question has always been to the developer of the PowerCranks as to whether more can be done.

Marketing claims are evidence of nothing.

1. Evaluate the difference in technique when training on PowerCranks and when riding standard, fixed, cranks to see if the adaption is complete or further training is possible.

So you train to adapt to a pedalling technique that you can't use in competition and research (Fernandez-Pena, 2009) has shown is rapidly lost when you go back to coupled cranks.

2. Evaluate any change in technique with time. Whether a race lasts 2 minutes or 5 hours if pedalling technique substantially deteriorates at the end of the period this would suggest that more aerobic training is indicated. If there is no deterioration in technique then emphasis can be placed on improving power.

Would be more concerned about fatigue and training to meet the demands of competition than a deterioration of pedalling technique.

3. The ability to measure pedal forces at any point in the pedal circle gives the ability to look for specific muscle or coordination weaknesses since different muscles are active at different points on the circle.

The main issue in cycling is sustaining the necessary power to meet the demands of the event.

This gives one the ability to concentrate on drills to enhance specific weaknesses should they be

identified. For instance, an analysis of the torque curves provided to me earlier uncovers the following issues:

1. Both legs are doing substantial negative work for a large portion of the upstroke and across the top.

2. Also, the right leg is substantially weaker than the right leg on the upstroke.

Unproven that this has a significant effect on performance.

3. The left leg has a substantial delay before applying a positive torque when coming over the top. Ideally positive torque should start 30-45º before TDC (similar to how positive torque continues 30-45º past BDC).

4. Comparing how the graphs change with time should give valuable information as to the aerobic endurance of the various muscles.

Unproven.

5. The ability to measure pedal forces around the circle at different cadences allows one to determine the most effective cadence for any rider at that power level.

Cadence is a red herring.

It is not possible to gather any of the above information using current techniques yet all of the information is potentially useful to both the coach and the athlete.

Unproven.

RUNNERS

PowerCranks have shown themselves to be useful to enhance running speed in average runners and in helping runners recover from injury without losing speed despite not running. Enhanced benefits include:

Uh huh, two studies so far (see Powercrank thread) that would suggest otherwise.

1. The ability to measure pedal forces at any point in the pedal circle gives the ability to look for and document specific muscle weaknesses since different muscles are active at different points on the circle. This gives one the ability to concentrate on drills to enhance specific weaknesses should they be identified.

Uh-huh, using cycling muscle activation to assess running muscle activation

2. Runners with substantial weaknesses or imbalances can be withheld from hard running activity until these weaknesses and imbalances are corrected which should lead to lower risk of injury.

Uh-huh, using cycling muscle activation to assess running muscle activation

3. Evaluate any change in technique with time. Whether a race lasts 2 minutes or5 hours if pedalling technique substantially deteriorates at the end of the period this would suggest that more aerobic training is indicated. If there is no deterioration in technique then emphasis can be placed on improving power.

And this helps running

It is not possible to gather any of the above information using current techniques yet all of the information is potentially useful to both the coach and the athlete.

Again, unproven.

MEDICAL AND REHAB PROFESSIONALS

PowerCranks have proven to be useful to medical and rehab professionals because of their ability to diagnose and correct lower extremity imbalances while still providing a good aerobic workout. It is why they have been chosen to be used by world champion Football, Baseball, and Rugby teams. Enhanced benefits if the iCranks should include:

Frank, you're letting the side down. It's been proven so you must have a link to the medical journal this was published in!

1. The ability to measure pedal forces at any point in the pedal circle gives the ability to look for and document specific muscle weaknesses since different muscles are active at different points on the circle. Documenting specific weaknesses should help when interacting with insurance companies when requesting authorization to treat.

A very long bow.

2. Allowing the documentation of weakness also allows for the documentation of improvement seen with treatment making assurances to athletes or coaching staff that recovery is complete based upon objective data or making requests for additional time (or continuing to hold athletes off the field) based upon continued objective data.

Again unproven.

It is not possible to gather any of the above information using current techniques yet all of this extra information is potentially useful.

Biomechanical assessments of the effect of visual feedback on cycling for patients with stroke

Abstract

Stroke patients exhibit abnormal pattern in leg cycling exercise. The aim of this study was to investigate the effects of visual feedback on the control of cycling motion in stroke patients from kinesiological, kinematic and kinetic aspects. The cycling performance derived from cycling electromyography (EMG), cycling cadence, and torque of forty stroke subjects was evaluated under conditions with and without visual feedback of cycling cadence. Kinesiological indices, shape symmetry index (SSI) and area symmetry index (ASI) were extracted from EMG linear envelopes to evaluate the symmetry of muscle firing patterns during cycling. Roughness index (RI) was calculated from cycling cadence to represent cycling smoothness from kinematic aspects. Averaged cycling power (Pav), the product of cadence and torque, was used to represent force output. The rectus femoris EMG showed significantly greater ASI with visual feedback, however, the difference in SSI between the two conditions was not significant. For the biceps femoris, there was a significant decrease in SSI with visual feedback, while the ASI was not affected significantly by the task conditions. The cycling smoothness was better and the average power generated was larger when visual feedback was provided. This study found that the addition of visual feedback improved both neuromuscular control and overall performance. Such improvement is likely to be the result of better control of the rectus femoris muscle activation and coordination of both legs.

A little bit more equipment providing feedback than what an iCrank will offer

 

[FrankDay]

Here is something I didn't expect. Just got an email from the iCranks people. He tells me the rider above (example 2 if you download the software) is a pro cyclist. Now, I will say that I think people tend to modulate their power, especially at low power, by adjusting the back pressure more than the pushing pressure which might explain the fairly large negative forces at this low power but it doesn't explain the imbalance. Apparently this rider was shocked when he saw this dynamic.

 

[CoachFergie]

An anecdote even with pretty pictures is still just an anecdote.

We await scientific validation of the measurement equipment before we may register any emotion.

Judging by the marketing claims on the iCrank site there there has been little if any validation of their product.

 

[FrankDay]

We await scientific validation of the measurement equipment before we may register any emotion.

Fergie, you are registering plenty of emotion now, me thinks.

 

[CoachFergie]

Fergie, you are registering plenty of emotion now, me thinks.

Compared to last week where riders I coach won 9 NZ titles the level of emotion above is closer to me being dead.

Did you have a point pertaining to the measurement or the claimed enhancement of pedalling in your post?

 

[FrankDay]

Did you have a point pertaining to the measurement or the claimed enhancement of pedalling in your post?

Are you referring to the iCranks data? If so, I think it is pretty obvious to anyone with even a rudimentary understanding of engineering/mechanics/physics how such data MIGHT BE USED to enhance performance. To anyone who doesn't have the educational background to understand this potential from a quick glance any explanation I might make probably won't help.

 

[CoachFergie]

Are you referring to the iCranks data? If so, I think it is pretty obvious to anyone with even a rudimentary understanding of engineering/mechanics/physics how such data MIGHT BE USED to enhance performance. To anyone who doesn't have the educational background to understand this potential from a quick glance any explanation I might make probably won't help.

Is there anything published that validates the iCrank tool? Judging by some of the claims made on their site that would be a good place to start.