Power Meters and Pedaling Effectiveness

[RapDaddyo]

Any suggestions for my reading list?


Here's a start:

a good power forum:

http://lists.topica.com/lists/wattage/read


the first 6 items here (especially the guides by Coggan and Howe):

http://www.midweekclub.com/articles/


the only software to use and some great info (look at "Power411"):

http://www.cyclingpeakssoftware.com/


Ric's site with good power info:

http://www.cyclecoach.com/

Thanks. I had actually stumbled across most of those links in my readings to date, but it's helpful to have them in one place. Is Coggan's list of references at the end of his paper the best biblio on the technical journals stuff? I notice that his paper is dated 2003. Have there been any more recent studies that I should look at?

 

[biker-linz]

As in all areas of novelty there is a great lack of knowledge and many self appointed experts-many with a financial axe to grind. Beware.

How true this is. However don't let this make you into a cynic. There are also some very fine minds indeed available who make no money whatever for contributing their time and effort on forums such as these.

My experience to this point is that PM's are useful in that they give an objective target against which to train. Heart rate (HR) is a reactive phenomenon influenced by many other factors. The difficulty, a very great difficulty, is in determining accurate Endurance, Tempo, etc. zones. This is because lab and road conditions don't match and results given by different PM's don't match either.

If all you use your PM for is to guide intensity during training you are missing out IMHO. However bear in mind that 'zones' are just that, and don't necessarily have to be *that* accurate. More important is to keep regular records of power output across several of the same sessions. Also very few coaches who know what they're talking about would attempt to 'transfer' Watts measured on one meter to another if you catch my drift. If measurements are made like for like and the PM is properly calibrated PMs are capable of being very accurate, although I would limit that to Powertaps and SRM Pros and above.

The technical problems with PM's are too numerous to itemize here. PM's all have unique technical problems that one will have to tolerate if you go the PM route.

I have *no* financial incentive to say this but I have owned and used Powertaps for a couple of years now and they have been virtually faultless. This includes an SL. Bear in mind that the disgruntled will always make more noise than the satisfied.

The physical challenge using PM's is not only to maintain one's training zones but to learn the proper pedaling technique to insure a smooth power output-also not easy.

As has been discussed elswhere there is absolutely no evidence to support the contention that 'smooth' pedalling is either a good or a desirable thing. Secondly a power meter is absolutely not the way to examine pedalling mechanics as their resolution is too poor to gather useful data regarding torque application during a duty cycle, unless you have access to an SRM equipped with torque output (and even then you have to be aware of the limitations). This job is almost entirely the preserve of force-instrumented pedals. If your goal is to measure peak power the job is still difficult to do. Jim Martin's inertial-loading method is probably the only technique which generates usable results.

One can, and must, in my opinion, also continue to monitor HR, cadence, etc. as before the advent of PM's, but learn to use them as adjuncts to cycling fitness and not as a training goal per se.

Again, there is a great deal of information regarding cadence in the scientific literature but as yet there is not a definitive picture of how it affects the physiological responses of a range of different cyclists. Bearing this in mind I feel that gathering cadence data is possibly a waste of time unless you intend to use it in conjuction with PM data to generate force-velocity curves (similar to the ideas being kicked around by Andy Coggan).

L.

 

[n crowley]

How true this is.







As has been discussed elswhere there is absolutely no evidence to support the contention that 'smooth' pedalling is either a good or a desirable thing.





The fact is, you don't know what is really meant by the most effective smooth pedalling technique., if you did, you could not make such a statement.
The true meaning of smooth pedalling is attempting to raise power output in the weakest areas of your stroke to equal that in your peak output area around 3 o'c and it is possible. Circular pedalling and smooth pedalling are completely different techniques, with circular pedalling the opposite is done, peak output is reduced.

 

[biker-linz]

The fact is, you don't know what is really meant by the most effective smooth pedalling technique., if you did, you could not make such a statement.

I didn't say 'most effective smooth pedalling techniqe', what I said was

there is absolutely no evidence to support the contention that 'smooth' pedalling is either a good or a desirable thing.

There is in fact no evidence to support the contention that *any* pedalling technique is better than any other (despite your repeated claims Noel). However I think both of our points of view are pretty well-known so let's not get into an ***-for-tat about it (I'm way too busy).
L.

 

[beerco]

Noel,

No, you can't raise your power in the weak areas to that around 3:00. Those other muscles just aren't strong enough. Stop being silly. Your legs are not electric motors nor will they ever be. Just like a two cylinder piston engine will never apply even max torque around 360o, neither will any human being at high power levels.

 

[n crowley]

Noel,

No, you can't raise your power in the weak areas to that around 3:00. Those other muscles just aren't strong enough. Stop being silly. Your legs are not electric motors nor will they ever be. Just like a two cylinder piston engine will never apply even max torque around 360o, neither will any human being at high power levels.

Nobody said that to Anquetil, he could do it and so could anyone else if they were interested enough. As for the evidence of the effects of smooth constant max power, Jean Bobet would be a good place to start. You say it can't be done, did anyone ever seriously try ? The error that all researchers make is in believing that maximum pedal power can only be applied in a vertical direction.

 

[ric_stern/RST]

Nobody said that to Anquetil, he could do it and so could anyone else if they were interested enough. As for the evidence of the effects of smooth constant max power, Jean Bobet would be a good place to start. You say it can't be done, did anyone ever seriously try ? The error that all researchers make is in believing that maximum pedal power can only be applied in a vertical direction.

Noel, there have been people offering you money and the opportunity to demonstrate, in a lab, this special pedalling style. Why did you not take up Andy or Wayne's offer?

 

[RapDaddyo]

As has been discussed elswhere there is absolutely no evidence to support the contention that 'smooth' pedalling is either a good or a desirable thing. Secondly a power meter is absolutely not the way to examine pedalling mechanics as their resolution is too poor to gather useful data regarding torque application during a duty cycle, unless you have access to an SRM equipped with torque output (and even then you have to be aware of the limitations). This job is almost entirely the preserve of force-instrumented pedals. If your goal is to measure peak power the job is still difficult to do. Jim Martin's inertial-loading method is probably the only technique which generates usable results.

You make some unequivocal statements about one of my original questions. One of the differences between the six or so PM products (counting the multiple models offered by PT and SRM) is the feature of capturing and analyzing what I have called symmetric/asymmetric pedaling patterns. From my reading, only the SRM Pro with optional torque analysis featue and the Polar offer this option. Maybe I should have said "balanced" pedaling patterns. I was talking about whether my legs are generating significantly different amounts of force relative to each other in the downstroke, and whether this varies at different cadences, power levels and the like. If so, I would think it desirable to work on attaining better balance, obviously by working on raising the force being applied by my "weak" leg to the level of my "strong" leg. You seem to be saying that the PM products can't be used for this purpose because the data aren't sufficiently accurate for this purpose. Thus, the only option is to use force-instrumented pedals. Further, you may be saying that there is no evidence to suggest that a balanced pedaling pattern is desirable. Have I got your position right?

 

[biker-linz]

One of the differences between the six or so PM products (counting the multiple models offered by PT and SRM) is the feature of capturing and analyzing what I have called symmetric/asymmetric pedaling patterns. From my reading, only the SRM Pro with optional torque analysis featue and the Polar offer this option. ?

I believe the Computrainer also offers 'Spinscan', but I think you're right regarding on-bike PMs, yes.

Maybe I should have said "balanced" pedaling patterns. I was talking about whether my legs are generating significantly different amounts of force relative to each other in the downstroke, and whether this varies at different cadences, power levels and the like.

This presents a whole other problem again, something we just discovered in the lab trying to analyse pedalling mechanics (even using an SRM Science with torque analysis). Basically you run into the problem that the torque measures obtained this way are a sum of both crank forces, so you still can't say with any certainty which leg is contributing what.

If so, I would think it desirable to work on attaining better balance, obviously by working on raising the force being applied by my "weak" leg to the level of my "strong" leg. You seem to be saying that the PM products can't be used for this purpose because the data aren't sufficiently accurate for this purpose. Thus, the only option is to use force-instrumented pedals. Further, you may be saying that there is no evidence to suggest that a balanced pedaling pattern is desirable. Have I got your position right?

I'm not sure about the whole L/R balance issue to be honest with you; I don't think there are any data either way. This is in contrast to the pedalling 'technique' issue, where there *are* data, they just don't say what people want them to say!

L.

 

[RapDaddyo]

Basically you run into the problem that the torque measures obtained this way are a sum of both crank forces, so you still can't say with any certainty which leg is contributing what.

Well, I am making a key assumption here, specifically that my legs are producing more force on their downstrokes than the other leg is producing on its upstroke. I make this assumption for two reasons, one general and one particular to me. My first assumption is that my muscles can produce more force on the downstroke than the upstroke. If there was a contest, the leg pulling up would lose to the leg pushing down. My second assumption is that this is particularly the case with me, since I have never particularly worked on pulling up or pedaling in a circular fashion. The only pedaling mechanics work I have done is to try to get smoother at all cadences by practicing from time to time at high cadences (e.g., 125-140). So, if I'm pulling up it's just a natural, instinctive thing, whereas I am acutely aware of pushing down.

 

[gholl]

How true this is. However don't let this make you into a cynic. There are also some very fine minds indeed available who make no money whatever for contributing their time and effort on forums such as these.


If all you use your PM for is to guide intensity during training you are missing out IMHO. However bear in mind that 'zones' are just that, and don't necessarily have to be *that* accurate. More important is to keep regular records of power output across several of the same sessions. Also very few coaches who know what they're talking about would attempt to 'transfer' Watts measured on one meter to another if you catch my drift. If measurements are made like for like and the PM is properly calibrated PMs are capable of being very accurate, although I would limit that to Powertaps and SRM Pros and above.


I have *no* financial incentive to say this but I have owned and used Powertaps for a couple of years now and they have been virtually faultless. This includes an SL. Bear in mind that the disgruntled will always make more noise than the satisfied.

As has been discussed elswhere there is absolutely no evidence to support the contention that 'smooth' pedalling is either a good or a desirable thing. Secondly a power meter is absolutely not the way to examine pedalling mechanics as their resolution is too poor to gather useful data regarding torque application during a duty cycle, unless you have access to an SRM equipped with torque output (and even then you have to be aware of the limitations). This job is almost entirely the preserve of force-instrumented pedals. If your goal is to measure peak power the job is still difficult to do. Jim Martin's inertial-loading method is probably the only technique which generates usable results.



Again, there is a great deal of information regarding cadence in the scientific literature but as yet there is not a definitive picture of how it affects the physiological responses of a range of different cyclists. Bearing this in mind I feel that gathering cadence data is possibly a waste of time unless you intend to use it in conjuction with PM data to generate force-velocity curves (similar to the ideas being kicked around by Andy Coggan).

L.

This post is quite typical of what one needs to beware.
It eminates from a commerical coaching website-the poster represents himself (herself?) as a disinterested party. I doubt this is true and the poster should immediatley state his (or her) conflicts of interest. It would also be interesting to know what the meaning of the poster's background is-what level of student at what institution, etc. I mention this because, just as an example, some self-styled experts glorify themselves as members of a British Cyling Coach Organization-but this organization has no official connection with British Cycling!
Now as to the points raised by this post.
Neither myself nor anyone contends that the sole use of PM's is for guiding intensity during workouts-however, it's obviously the main use. Needless to say, results must be recorded, compared, etc.
Accurate Endurance and other zones ar not easy to determine for many reasons-the data obtained under lab conditions (free of road problems) can't be readily translated to the road. PM's are difficult to use and data obtained on the road isn't always uniform.
The poster's experience with PowerTap is unique-the problems with this equipment are legend-as are problems with ALL PM's.
As for smooth pedaling, I contend that without a smooth pedaling technique readable Wattage information won't be available during a ride-unless the user's PM has an active smoothening feature for Watts.
Whether or not smooth pedaling is a good thing or not is a value judgement. I have no opinion on the matter at present, however, looking at LA's TDF results, I suspect it may be important. Ditto for cadence.

 

[biker-linz]

Well, I am making a key assumption here, specifically that my legs are producing more force on their downstrokes than the other leg is producing on its upstroke. I make this assumption for two reasons, one general and one particular to me. My first assumption is that my muscles can produce more force on the downstroke than the upstroke. If there was a contest, the leg pulling up would lose to the leg pushing down. My second assumption is that this is particularly the case with me, since I have never particularly worked on pulling up or pedaling in a circular fashion. The only pedaling mechanics work I have done is to try to get smoother at all cadences by practicing from time to time at high cadences (e.g., 125-140). So, if I'm pulling up it's just a natural, instinctive thing, whereas I am acutely aware of pushing down.

*Everybody* demonstrates a peak on their downstroke, so you're in great and numerous company! What I meant was not necessarily that you pull *up* on the upstroke, but that you might 'unweight' one leg more than the other (in fact you probably do). It is impossible to tell from a power meter torque trace how much this contributes to measurements of 'balance' from one leg to another. Actually one leg might just be slightly heavier than the other. Same muscular input, different force measures at the hub or cranks if summed together. For example, say your PM tells you that you generate 10% greater peak torque when your right crank is at 3 o'clock as opposed to your left crank is this:
a. because your right leg is generating greater peak torque or
b. your left leg is more 'unweighted' than your right
and vice versa? Without this information it is impossible to make corrections to the balance between your legs, even if it were desirable to do so. You might look at the data above and mistakenly conclude that you need to push harder with your left leg, when in truth both right and left legs are pushing equally hard and what you need to do is unweight one leg less (or the other leg more, if all you want is to even up the sum-forces). The comment in brackets sounds silly, but it is a good illustration of how evening up L / R balance might damage rather than enhance performance if taken to its logical conclusion.

L.

 

[biker-linz]

This post is quite typical of what one needs to beware. It eminates from a commerical coaching website-the poster represents himself (herself?) as a disinterested party. I doubt this is true and the poster should immediatley state his (or her) conflicts of interest.

The website is my own very small business. I do not sell power meters of any kind, nor to I make any kind of living out of coaching, so no conflicts of interest at all.

It would also be interesting to what the meaning of the poster's background is-what level of student at what institution, etc.

As stated in my signature I am an MSc student, studying Exercise Physiology at Wolverhampton University. I am currently doing a project as part of my Masters investigating the relationship between differing inertial loads and the responses of trained cyclists. In this venture we have had cause to gather torque data, so I have some experience.

I mention this because, just as an example, some self-styled experts glorify themselves as members of a British Cyling Coach organization-but this organization has no official connection with British Cycling!

The Association of British Cycle Coaches is a highly respected coaching organisation in its own right. I was not trying to be an expert either, I'm just presenting the data I have access to. If you would like me to send you references to back up all the points I have made I will try to find the time.

INow as to the points raised by this post.
Neither myself nor anyone contends that the sole use of PM's is for guiding intensity during workouts-however, it's obviously the main use.

It's *one* of the uses, but there are plenty more.

Needless to say, results must be recorded, compared, etc.
Accurate Endurance and other zones ar not easy to determine for many reasons-the data obtained under lab conditions (free of road problems) can't be readily translated to the road. PM's are difficult to use and data obtained on the road isn't always uniform.

As I stated in my original post, zones can be moderated 'on the fly' quite easily.

The poster's experience with PowerTap is unique-the problems with this equipment are legend-as are problems with ALL PM's.

I only shared my experience and have no apologies for doing so. I'm sure there are other happy PT users out there.

As for smooth pedaling, I contend that without a smooth pedaling technique readable Wattage information won't be available during a ride-unless the user's PM has an active smoothening feature for Watts.

I'm not sure I understand what you're getting at here; I know that wattage data are highly variable during a ride but most people either use a smoothing filter as you suggest or just average power across intervals.

Whether or not smooth pedaling is a good thing or not is a value judgement..

I disagree, there is strong evidence from published papers indicating otherwise.

I have no opinion on the matter at present, however, looking a LA's TDF results, I suspect it may be important. Ditto for cadence.

Unfortunately I don't have access to Armstrong's torque data so it's difficult to say.
I hope I have been of some help, although I won't be contributing any more to this thread.
All the best,

Lindsay

 

[jws]

This post is quite typical of what one needs to beware.


One does need to beware all the misinformation about training found on the web, but I think it's you, gholl, who is spreading some. Furthermore, Linz is very well informed, very objectively scientific, and contributes prolifically to useful info about cycling.

Armstrong is good because he generates more power, mostly because he was endowed with the talent (and works hard). What about all the local amateurs with "smooth" pedaling; why aren't they winning, or even Doing, the Tour.

The large majority of PT problems are very minor. The others are handled very well by great service. Still, most PT's have no problems at all and you never hear about those. I have no interest in PT except that I own a couple which work perfectly.

The most useful information you get from a pm is in looking at power averages over different time intervals, especially when going all out. It's surprising at first how reproducible the numbers are even when power is variable. However, ability to produce power is based on physiology which doesn't change all that quickly.

 

[gholl]

The website is my own very small business. I do not sell power meters of any kind, nor to I make any kind of living out of coaching, so no conflicts of interest at all. As stated in my signature I am an MSc student, studying Exercise Physiology at Wolverhampton University. I am currently doing a project as part of my Masters investigating the relationship between differing inertial loads and the responses of trained cyclists. In this venture we have had cause to gather torque data, so I have some experience.The Association of British Cycle Coaches is a highly respected coaching organisation in its own right. I was not trying to be an expert either, I'm just presenting the data I have access to. If you would like me to send you references to back up all the points I have made I will try to find the time.
It's *one* of the uses, but there are plenty more.As I stated in my original post, zones can be moderated 'on the fly' quite easily.
I only shared my experience and have no apologies for doing so. I'm sure there are other happy PT users out there.I'm not sure I understand what you're getting at here; I know that wattage data are highly variable during a ride but most people either use a smoothing filter as you suggest or just average power across intervals.
I disagree, there is strong evidence from published papers indicating otherwise. Unfortunately I don't have access to Armstrong's torque data so it's difficult to say.
I hope I have been of some help, although I won't be contributing any more to this thread.
All the best,

Lindsay

Perhaps you haven't yet studied the courses in semantics and ethics offered at Wolverhampton. Your website offers your coaching services at 40 Pounds/hour and you have the temerity to claim you have no conflict of interest here. You should be ashamed of yourself. It's obvious that the common thread in all your posts and other activities is the same-to draw attention to yourself in order to cultivate business-i.e. self-marketing. This is no crime in a capitalist culture-but at least have the decency to admit it.
Now as to your CV-apparently you are an amateur cyclist and undergraduate at a small university attempting to do a minor research project-even advertising for subjects on your website-nothing wrong here-but admit it, please.
As to the organization you belong to-I repeat it has nothing to do with official British Cycling at all-I will publish a post from the official organization if I must. Publishing your membership in the "Association of British Cycle Coaches "is deceptive at best.
The problem with posts from those who engage in subterfuge is that the information they appear to offer is poisoned.
I must again underscore certain points I previously made.
Endurance, Tempo and other Zones must be carefully constructed-perhaps someone can modify them "on the fly" but the results achieved are likely to be unreliable.
ALL PM's have technical problems-many have lots of problems-PowerTap is no exception-your experiences notwithstanding.
In non-laboratory conditions most PM's Wattage output is not smooth-unless a PM has an active smoothening feature it's not going to be easy to stay in a zone.
The issue of "smooth" pedaling is complex. I suspect that very precise, scientific definitions of terms must be made before any intelligent discussion can be made in this area. The notion that smooth pedaling is not a feature in elite cycling flies in the face of observation-however, scientific fact in this area is scant.
As far as your access to LA's torque data, I doubt you're going to get any despite your article about him. It would be more interesting to know whose data you do have and what use you've made of it.

 

[ric_stern/RST]

As to the organization you belong to-I repeat it has nothing to do with official British Cycling at all-I will publish a post from the official organization if I must. Publishing your membership in the "Association of British Cycle Coaches "is deceptive at best.

I don't believe anyone has suggested that the Association of British Cycle Coaches is anything to do with (the) British Cycling (Federation). The ABCC is far older coaching association and predates the very recent coaching effort from BC by a long way (not that i am in anyway infering that the BC's coaching isn't 'good enough'). The ABCC has been established for a long time. It is in no way deceptive.

I therefore suggest that you offer Lindsay an immediate and unconditional apology.

Ric

 

[RapDaddyo]

*Everybody* demonstrates a peak on their downstroke, so you're in great and numerous company! What I meant was not necessarily that you pull *up* on the upstroke, but that you might 'unweight' one leg more than the other (in fact you probably do). It is impossible to tell from a power meter torque trace how much this contributes to measurements of 'balance' from one leg to another. Actually one leg might just be slightly heavier than the other. Same muscular input, different force measures at the hub or cranks if summed together. For example, say your PM tells you that you generate 10% greater peak torque when your right crank is at 3 o'clock as opposed to your left crank is this:
a. because your right leg is generating greater peak torque or
b. your left leg is more 'unweighted' than your right
and vice versa? Without this information it is impossible to make corrections to the balance between your legs, even if it were desirable to do so. You might look at the data above and mistakenly conclude that you need to push harder with your left leg, when in truth both right and left legs are pushing equally hard and what you need to do is unweight one leg less (or the other leg more, if all you want is to even up the sum-forces). The comment in brackets sounds silly, but it is a good illustration of how evening up L / R balance might damage rather than enhance performance if taken to its logical conclusion.

L.

You make a good point. And, without doing some experimenting I don't know whether I would be able to achieve my primary objective (generate max power over the desired duration) with a more balanced pedaling pattern than I do now (assuming that I have an unbalanced pattern). As to PMs, the issue in my mind is whether any of the available products supports such an endeavor or whether I would need to find a lab with force-instrumented pedals.

I appreciate your inputs on this thread. If I didn't learn to absord and reconcile competing and contradictory information from multiple sources before I got a master's and doctorate from a prestigious university in Boston, I certainly did then. I started this thread and I welcome any and all contributions to the questions I asked. I am here to learn, and successful cyclists and coaches have an abundance of knowledge that I don't. I welcome your input. And, by the way, I have spent a fair bit of time in the UK. Your food's lousy, but your real ale (I always liked Ruddles County) and cyclists and football players and golf courses aren't too shabby.

 

[gholl]

I don't believe anyone has suggested that the Association of British Cycle Coaches is anything to do with (the) British Cycling (Federation). The ABCC is far older coaching association and predates the very recent coaching effort from BC by a long way (not that i am in anyway infering that the BC's coaching isn't 'good enough'). The ABCC has been established for a long time. It is in no way deceptive.

I therefore suggest that you offer Lindsay an immediate and unconditional apology.

Ric

Why Mr. Stern what would you have me retract? As a member of the ABCC ( the qualification is used in your own self-promotion) you must know that the ABCC has the same relationship with official British cycling as the Salvation Army with the British Army-that is to say-none. The innocent reader has no way to know this. You also know that neither you nor your compatriot have ever attended the courses given by or obtained a certification from the official organ of British cycling-The British Cycling Federation. I'll be happy to publish a communication from them specifically about you, if you like. I thought this a deception then; I think it a deception now. I've given you my reasons, which I here dare you to refute. Your rage I defy.
Neither your own CV or business practices are so formidable either, and as for your own morals (which we've discussed in private), like those of your friend, incline me to regard not what you shall say, but what you can prove.
Recall that I sought to keep these matters private but your actions give me no choice but to make them public.

 

[acoggan]

I'm not sure about the whole L/R balance issue to be honest with you; I don't think there are any data either way.

Actually, there are, mostly for untrained subjects, but also at least one study of trained cyclists as well. The most salient points would seem to be: 1) asymmetries of up to 10% are very common, but 2) which leg is dominant can vary depending on the power output, the cadence, and even from day to day. The latter in particular would seem to make it a difficult issue to address from a performance/training priorities perspective.

 

[Smartt/RST]

.... Furthermore, Linz is very well informed, very objectively scientific, and contributes prolifically to useful info about cycling.

Indeed, to this forum and others.