Pedal Technique-Write up and examples

bahzob

I got asked elsewhere, again, to explain why how you pedal a bike makes a difference to the power you produce.

The link here, a cut/paste from Wattbike, provides a good overview this.

http://www.cyclosport.org/09-Feb-2011/training/general-fitness/pedalling-technique-and-the-wattbike.html

(The examples are straightforward but may take a bit of time to get familiar with. The bottom line though is simple
- Cycling performance is directly linked to the ability to produce sustained power
- Power is a function of the average torque per revolution * cadence
- The key difference between a good and bad pedal style is that a good style has more consistent and therefore higher average torque per rev than a bad one.
- Maintaining a good consistent style become progressively more difficult as power increases..
- It is therefore no surprise that top cyclists have the most consistent style. And that they are capable of sustaining this at higher power and revs which is one reason why they can push 2kW@150+rpm in sprints and sustain 400W+@90rpm for 60mins+ up mountains.)

Unless you are already an elite cyclist it is, tbh, unlikely that your pedal style will match the "peanut" that is typical of theirs. It is more likely to be a "figure of eight" or a "peanut". If this is the case this is in fact good news. It means that with a little focus while doing normal training, it should be possible to adapt your style and produce more power for a given amount of effort. Which at the end of the day is what training is all about.

Tom Dean

Nice advertisment for Wattbike. Do you work for them?

bahzob wrote:

- The key difference between a good and bad pedal style is that a good style has more consistent and therefore higher average torque per rev than a bad one.

Have you any evidence for this. What do you mean by good and bad?

bahzob wrote:

- It is therefore no surprise that top cyclists have the most consistent style.

Can you show any evidence for this? (not a video of top cyclists)

bahzob wrote:

it should be possible to adapt your style

How?

bahzob

Also, for those planning to do events like the Etape/Marmotte.

The long climbs in these events amplify the effect of losing momentum every stroke as happens with a poor style.

You may not notice this cruising along on a flat road, but it becomes very apparent if you have to do 10miles up a gradient of over 8%.

bahzob

For the record I don't have any connection with Wattbike.

The only reason I cite them is that I happened to try out one of their bikes at an event I was at and found to my chagrin that the pedal style I thought was pretty good wasn't.

I made some changes as a result and got better.

Since this is the purpose of this forum I thought I would share the experience.

My guess is that my experience is by no means an exception so hope others will benefit. If you choose not to then I really don't care.

imposter2.0

bahzob wrote:

I got asked elsewhere, again, to explain why how you pedal a bike makes a difference to the power you produce..

Er, no you didn't. Specifically, what you were asked was HOW you adapt your pedalling technique to produce that improvement. You seem to be really struggling with this. Or avoiding it. Maybe you just don't know.

Tom Dean

bahzob wrote:

My guess is that my experience is by no means an exception so hope others will benefit. If you choose not to then I really don't care.

Fair enough. Don't be surprised if some people don't assign much value to your guess. You could have admitted a while ago that guessing was all your were doing and avoided all the tiresome questions.

Alex_Simmons/RST

bahzob wrote:

- Power is a function of the average torque per revolution * cadence
- The key difference between a good and bad pedal style is that a good style has more consistent and therefore higher average torque per rev than a bad one.

Attaining a higher average torque and applying a more even application of torque around a pedal stroke are totally different things. I'm not sure if by "more consistent" you mean the latter but it seems that's what you are inferring. Correct me if I'm wrong.

Of course a higher average torque, for the same pedal speed, results in more power.

What is not demonstrated with any convincing evidence is that a more even application of torque leads to a higher average torque. It's a non sequitur argument.

For people interested in pedalling biomechanics and performance, I suggest they keep their eye on work coming out of the Neuromuscular Function Lab, University of Utah, and sometimes in collaboration with the AIS.

GiantMike

So, is it possible for me to improve my pedal technique and improve my power transfer from peanut to sausage?

Alex_Simmons/RST

GiantMike wrote:

So, is it possible for me to improve my pedal technique and improve my power transfer from peanut to sausage?

First we need to define pedal technique.

Then decide what an improvement in technique actually means. At present it all seems rather subjective.

IMO, such net crank force plots are not a measure of technique. They are just net crank force plots, and net force can be attained through various combination of individual pedal forces, as well as various combinations of contributions from the musculature controlling the hip, knee and ankle joints. There is nothing to suggest one combination is necessarily superior to another.

GiantMike

Alex_Simmons/RST wrote:

GiantMike wrote:

So, is it possible for me to improve my pedal technique and improve my power transfer from peanut to sausage?

First we need to define pedal technique.

Then decide what an improvement in technique actually means. At present it all seems rather subjective.

IMO, such net crank force plots are not a measure of technique. They are just net crank force plots, and net force can be attained through various combination of individual pedal forces, as well as various combinations of contributions from the musculature controlling the hip, knee and ankle joints. There is nothing to suggest one combination is necessarily superior to another.

I would say that an improvement in pedal technique would allow me to produce more power over a set period of time from the same level of CV fitness, i.e. improvements would be brought about by changes in technique (which may or may not be combined with changes the rider's position on the bike).

Therefore, I'd define pedal technique as the action that transfers power from the leg(s) to the pedal(s).

imposter2.0

GiantMike wrote:

I would say that an improvement in pedal technique would allow me to produce more power over a set period of time from the same level of CV fitness,

Why would you say that - when nobody has actually been able to provide any evidence to support it ???

GiantMike

Imposter wrote:

GiantMike wrote:

I would say that an improvement in pedal technique would allow me to produce more power over a set period of time from the same level of CV fitness,

Why would you say that - when nobody has actually been able to provide any evidence to support it ???

What the f*ck is this, some kind of amateur science show? Who's got the best fake science qualification? Who can knock somebody else quickest and best?

I say that because it's my f*cking opinion. How many decimal places would you like me to state my opinion to? If you prefer yours then that's fine. Great even. If you don't like mine then please ignore it and trot off and bother somebody else. However, if I've misjudged your post and you're not an irritating c0ck, please disregard the above.

imposter2.0

GiantMike wrote:

What the f*ck is this, some kind of amateur science show? Who's got the best fake science qualification? Who can knock somebody else quickest and best?

This is the 'training' forum - not the 'let's make stuff up and pretend it's true' forum. If you want to claim random bollox, go to Cake Stop FFS.

GiantMike wrote:

I say that because it's my f*cking opinion. How many decimal places would you like me to state my opinion to? If you prefer yours then that's fine. Great even. If you don't like mine then please ignore it and trot off and bother somebody else. However, if I've misjudged your post and you're not an irritating c0ck, please disregard the above.

Jesus. You 'pedal technique' types really don't like being challenged

GiantMike

giantmike wrote:

Imposter wrote:

What the f*ck is this, some kind of amateur science show? Who's got the best fake science qualification? Who can knock somebody else quickest and best?

This is the 'training' forum - not the 'let's make stuff up and pretend it's true' forum. If you want to claim random bollox, go to Cake Stop FFS.

What random bollox have I claimed? I stated on opinion.

As this is the 'training' forum I thought it was a good place to find out about training. I didn't realise I had to have my opinions assessed and graded by the 'opinion police' to make sure they conform.

imposter2.0

GiantMike wrote:

As this is the 'training' forum I thought it was a good place to find out about training. I didn't realise I had to have my opinions assessed and graded by the 'opinion police' to make sure they conform.

I simply asked you WHY you held that opinion. Having opinions is fine by the way - the trick is being able to explain them if someone asks...

GiantMike

Imposter wrote:

I simply asked you WHY you held that opinion. Having opinions is fine by the way - the trick is being able to explain them if someone asks...

No, the trick is to not feel like you have to justify your opinions to every tw@t on the internet that wants to start a pseudo-scientific debate about evidence and proof.

I think you're too used to knocking other people about what they say to realise how irritating you have become on these forums.

imposter2.0

I see a pattern emerging here....

mamba80

When i first read Bahzobs posts on pedal tech etc - i thought what a load of rubbish, its all down to your ftp etc etc etc (which obviously has a huge bearing)
Well i've just come back from 8 days in Majorca and i thought i d focus a bit more on my form and keep it together a bit more, all i can say is that i found it easier and faster to focus on pedalling techniq, pushing over the top, dragging back more and unweighting the trailing leg (basic stuff but gets forgotten when your tired)
i ve been riding a bike over 30yrs and i didnt think that on that score id have anything to learn - ok it wont make the difference in a 2/3/4 rr but on 30 to 60 min climbs it might just for some.
And NO i dont have shred of evidence either

Tom Dean

Focussing on something other than the pain in your legs is never a bad thing I guess!

It does not follow however, that the thing you are focussing on is making you go faster.

amaferanga

It's one thing saying that you think doing x, y or z may have helped your training, but it's another to post nonsense like bahzob does as if he's some kind of expert on the subject matter. Like others, if he could actually back up what he claims then I'd listen, but his n=1 experience and a few guesses and hunches don't make science and are actually beginning to make him sound deluded about his apparent authority on the subject.

GiantMike

Imposter wrote:

I see a pattern emerging here....

Excellent. Get some more evidence, analyse it, get it peer reviewed and then you might be able to post your opinon on this hallowed academic forum.

jibberjim

Has anyone tried to walk very slowly up the stairs? by applying a small amount of force continously to lift one leg and then repeating for the other? And then tried bounding up the stairs with a little jump on each step?

I have - and I find one really tough and I get tired even walking up a couple of flights, and the other really easy and natural. The same external work is done in both instances, so shouldn't they both be the same? I've always thought this was a good indicator of the way I should be pedalling, given that the action is somewhat similar with a repeated alternating force on the legs.

Have other people noticed similar?

bernithebiker

jibberjim wrote:

Has anyone tried to walk very slowly up the stairs? by applying a small amount of force continously to lift one leg and then repeating for the other? And then tried bounding up the stairs with a little jump on each step?

I have - and I find one really tough and I get tired even walking up a couple of flights, and the other really easy and natural. The same external work is done in both instances, so shouldn't they both be the same? I've always thought this was a good indicator of the way I should be pedalling, given that the action is somewhat similar with a repeated alternating force on the legs.

Have other people noticed similar?

I fear you may be asked to produce evidence for that.......

Alex_Simmons/RST

GiantMike wrote:

I would say that an improvement in pedal technique would allow me to produce more power over a set period of time from the same level of CV fitness,

OK, well we already have a well established measure for that - Gross Mechanical Efficiency, i.e. the ratio of energy delivered to the cranks as a proportion of energy metabolised. If GME goes up, then what you describe has occurred.

GME is measurable in the lab - typically requires gas exchange analysis.

GiantMike wrote:

i.e. improvements would be brought about by changes in technique (which may or may not be combined with changes the rider's position on the bike).

OK, so what is described is a premise that a change in technique may result in a change in GME.

I think Bahzob is also suggesting a premise that a change in technique may also result in a change in sustainable power output.

GME and power output is reported in studies that look at different aspects of pedalling, so we already have some information to work with. Certainly better than data on net force plots and personal anecdote.

GiantMike wrote:

Therefore, I'd define pedal technique as the action that transfers power from the leg(s) to the pedal(s).

OK, that sounds good.

But measurement of what you refer to as technique is far more complex than what we are viewing with any net force plot from a Wattbike. Hence I consider the use of such plots as a measure of technique to be a flawed premise to begin with.


So then we need understanding of what these plots actually tell us (oft misunderstood), and

whether they can still be of use and/or provide any actionable intelligence (debatable but certainly not well established and is mostly full of speculation), and

if so then what training intervention we should consider and how one might go about that (not actually described here, or in a manner than can be readily implemented, and as pointed out, what one feels or thinks they are doing is often not what they are actually doing), and

determine if/how one can measure such a thing because if we can't, then attributing changes to such things is again only ever going to be speculation.


I think this is what Bahzob is wanting to do, but the chain from a net force plot to actionable intelligence, description and implementation of a training intervention, and appropriate measurement of performance is tenuous and speculative. There is nothing wrong with speculative but making it sound like it's absolute and clear is invalid.

I say we simply do not have the data as presented here to make such a leap, that comparing such force plots from individuals at different levels of development, experience and fitness is insufficient to imply a causal relationship, nor that such plots are a valid means to assess technique or instruct us on a particular form of training intervention that is clearly superior to others.


As an unrelated point, I see no reason for people to get narky at what you said. Seemed like reasonable statements, thoughts, ideas to me, and help us to break down the issue a little further.

BenderRodriguez

To return to something that I posted on an earlier thread, I do think that there is some evidence that applying torque on the down stroke in a more sustained manner, rather than with a short, high peak, does contribute to GE. For example:

INFLUENCE OF PEDALING TECHNIQUE ON METABOLIC EFFICIENCY IN ELITE CYCLISTS.
Biol. Sport 2012;29:229-233
DOI: 10.5604/20831862.1003448

This study measured the average and peak torque values for elite cyclists working at threshold and found that the longer the torque was applied (effectively meaning on the down stroke) the greater the Gross Efficiency (GE) "the ratio of how much mechanical work is produced compared to the overall metabolic energy expended". That is, 'simply pushing harder', so maximizing the peak torque generated, was much a less efficient strategy than that adopted by those riders who instead applied the torque through a longer proportion of the pedaling stroke. The difference measured was significant, with those who applied a more sustained application of torque achieving GE values in excess of 22%, as opposed to those with what might be called a 'punchier' pedaling style, whose GE was nearer 19%. Their conclusion?

…the lack of a significant relationship between the Tmax and the GE suggest that at the power outputs at which the LT and OBLA were produced, increases in GE are associated to increments in torque applied throughout the whole pedal revolution and not to increases in the maximum torque during the downward phase of the crank cycle.

See also:

Whole-body efficiency is negatively correlated with minimum torque per duty cycle in trained cyclists.

Journal of Sports Sciences 01/2009; 27(4):319-25.
DOI:10.1080/02640410802526916

ABSTRACT...The most notable results were as follows: gross efficiency (r = -0.72, P < 0.05 at 250 W) was inversely correlated with the ratio of minimum to peak torque, particularly at higher work rates. There was a highly significant inverse correlation between delta efficiency and average minimum torque at 200 W (r = -0.76, P < 0.01).

Also relevant to the discussion, though not a research paper:

Cycling Economy - Is it a better fitness predictor?
Written by: Edmund R. Burke, Ph.D.

http://www.peakfitnessnow.com/cyc_econ.htm

As to why this should be, it could well be that a more 'sustained' application of torque optimises the use of slow-twitch fibres, whilst a 'punchier' style, with its higher peak torque value, tends to recruit more fast-twitch fibres, and studies have suggested that economy is related to the preferential use of slow-twitch fibres over fast-twitch ones.

Of course, there are many caveats here. For one GE is related to many other things other than just pedaling technique. Secondly, economy seems to be related to power output, with economy playing a much more important role at near-threshold efforts than lower level efforts, something that many studies, such as the often-quoted 'Korff' study overlooked. Thirdly, not all pro level cyclists pedal in the most efficient manner, as defined above, and equal numbers of 'recreational' cyclists do have an optimally economic style. As with running there seems to be an interplay between having a high VO2 max and having good economy, with some pros who have a relatively poor VO2 max being able to compensate for this via having a higher than average economy. For example, see:

No Differences in Cycling Efficiency Between World-Class and Recreational Cyclists
Intj Sports Med 2004; 25:374-379
DOI 10.1055/S-2004-815M8

Inverse relationship between VO2max and economy/efficiency in world-class cyclists
MEDICINE & SCIENCE IN SPORTS & EXERCISE
The American College of Sports Medicine
DO1:10.1249/01.MSS.0000039306.92778.DF

GiantMike

Alex_Simmons/RST wrote:

But measurement of what you refer to as technique is far more complex than what we are viewing with any net force plot from a Wattbike. Hence I consider the use of such plots as a measure of technique to be a flawed premise to begin with.

Interesting. From the other end of the argument I think polar plots (net force plots) are a useful summary of all the complex forces and dynamics that go into a pedal stroke, assuming that pedal technique includes the following measurable outputs:

1. Start position of power stroke
2. Finish position of power stroke
3. Smoothness of power stroke
4. Average torque delivered per stroke
5. Cadence associated with 1-4 above

For example, if cyclist A's power stroke lasted from 2 to 4 o'clock, peaked considerably around 3 o'clock and was based on a cadence 60rpm, I'd say this was a worse technique than cyclist B's 1 to 5 o'clock smooth stroke at 90rpm [subjective kneejerk reaction].

However, polar plots do not measure the inputs to achieve the above outputs, for example whether muscles start working against eachother to achieve a longer stroke or whether energy is being wasted to achieve a smoother stroke, or whether a different technique allows a rider to maintain a certain power for longer.

What I don't understand, and was my initial question, was that if there was a preferred polar plot for different disciplines (for example), is it possible to train towards it (even though that may not be sensible)? Or does just doing the discipline alter the polar plot of the cyclist to be more efficient?

As an aside, I did 2 days of 'speed work' earlier this week focussing on cadence, spinning at around 100-105rpm rather than my usual sluggish 80-85. For the same perceived effort I produced less power and seemed to tire quicker and have a higher HR. Clearly this says nothing on its own, but I was surprised that a 25% increase in cadence seemed to have such an effect on my efficiency, either because I'm physiologically pre-determined to have a slower cadence or have trained for so long at 80-85 that my muscles work best there.

Tom Dean

BenderRodriguez wrote:

To return to something that I posted on an earlier thread, I do think that there is some evidence that applying torque on the down stroke in a more sustained manner, rather than with a short, high peak, does contribute to GE.

Interestingly, and assuming you are saying this is 'better' (although we know GE is not the same as performance)- compare this to the OP's Wattbike link, and their examples of worse and better pedalling; the figure of eight and the peanut. The latter plot, while more even through the whole stroke, seems to be less even with a peak in the downstroke.

Alex_Simmons/RST

Some more for interest:
http://www.ncbi.nlm.nih.gov/pubmed/18418807
http://www.ncbi.nlm.nih.gov/pubmed/20827654
http://www.ncbi.nlm.nih.gov/pubmed/1895355
http://www.ncbi.nlm.nih.gov/pubmed/10737268

and this one:

Alex_Simmons/RST

GiantMike wrote:

4. Average torque delivered per stroke
5. Cadence associated with 1-4 above

Well that's what's measured to determine power anyway.

GiantMike wrote:

What I don't understand, and was my initial question, was that if there was a preferred polar plot for different disciplines (for example), is it possible to train towards it (even though that may not be sensible)? Or does just doing the discipline alter the polar plot of the cyclist to be more efficient?

It's possible with a biofeedback mechanism to alter one's pedal plot during a session (there's a study somewhere where that was specifically done).

Whether that sort of specific training results in chronic changes to pedalling action is debatable (let alone whether such changes result in improved efficiency). For instance, a quite radical intervention to pedalling action is the use of independent clutch cranks, yet even after prolonged use, riders pretty quickly revert to former pedalling force patterns when they return to using normal cranks.

GiantMike wrote:

As an aside, I did 2 days of 'speed work' earlier this week focussing on cadence, spinning at around 100-105rpm rather than my usual sluggish 80-85. For the same perceived effort I produced less power and seemed to tire quicker and have a higher HR. Clearly this says nothing on its own, but I was surprised that a 25% increase in cadence seemed to have such an effect on my efficiency, either because I'm physiologically pre-determined to have a slower cadence or have trained for so long at 80-85 that my muscles work best there.

Most have a preferred cadence range, that's normal, and we don't operate as well outside of that, but we can certainly improve our performance outside of of comfort zone. Whether or not one needs to do that is an individual case by case matter.

Preferred / efficient cadence tends to rise with absolute and relative power output.

bernithebiker

This great! Intelligent discussion with noone pissing on anyone's fireworks.

We might just learn something here!

bahzob

bernithebiker wrote:

This great! Intelligent discussion with noone pissing on anyone's fireworks.

We might just learn something here!

Hopefully and eventually yes.

Please all get some focus on what those in denial that the way you pedal has an effect on your performance seem to be saying.

It boils down to a belief that in some magic way everyone pedals a bike perfectly and are incapable of improving despite the fact they seem to be doing it in a very different way and with very different results.

If true it would make pedalling quite unique in physiological terms and cycling unlike any other sport.

I am constantly being asked to "prove" my views yet all I am doing is stating the completely orthodox position that pedalling is just like every other skill,
- it varies due to a combination of genetics and experience.
- the portion that is not down to genetics can be improved by focused training and this will result in an improvement in overall performance.

Seriously, its not my views that are weird and wonderful it's those of those that seem to have a belief bordering on the religious to the contrary.

If I am in any way misrepresenting their view please can they state clearly what their position actually is rather than just saying what others think is wrong.