Power Meters and Pedaling Effectiveness

RapDaddyo

Thanks for the additional info about your personal experience w/PMs. I tend to get pretty well informed before I make important decisions and I consider spending $1K+ an important decision. Since I did my serious cycling before the availability of HR, cadence or PMs, and was reasonably successful, I don't hold out any bike computer info as the "holy grail." But, since the objective of cycling is to apply as much force to the cranks as possible for the required duration, it is pretty obvious that it would be useful to know how much power one is applying to the cranks at any point in time and averages over time. I understand the technologies underlying all four of the available products (I have read the patent applications), and I think I have a pretty good feel for the technical and maintenance shortcomings of each. I see a lot of discussion about accuracy, but to the extent that we're talking about 1.5% or 3%, I can't figure out why I care, so long as my device is consistent. If 200 watts is always 200 watts, it's fine with me, even if it's really 205 watts. Intermittent readings are, however, a problem.

As to training with a PM, I don't know that it will change my approach to training very much except that I will probably define my rides in power terms with a spot check of HR. I have a pretty simple philosophy for training. I ride for about 3 months mainly spinning whatever gear I can turn without feeling like I'm pushing hard. Then I start doing hard days followed by easy days. Hard is hard enough to make my thighs and lungs burn for at least 5 minutes at a time, sometimes more. Easy is easy enough to have a conversation with a riding buddy. The main difference is that with a PM I'll know what hard and easy are in watts. Whether that'll cause me to change the way I train, I don't know yet. But, there's no way I'm going to have a training schedule that looks like a NASA launch schedule.

RapDaddyo

Thanks for the input. When you say, "smooth usable wattage data ...", do you mean during the ride or post ride, or both? What's your take on the ability to produce smooth usable wattage data with the SRM Amateur? And, what is your experience with after-sale support for the SRM? What is warranted and how long is the warranty? I'm not overly concerned with the software choices, so long as the raw data can be exported in a standard file format (ASCII, CSV, etc.). If the vendor-supplied software and after-market software packages don't meet my needs, I'll just write my own analysis program. It's just a time-series data file and there are only a few variables of interest. It seems to me that the only parts of a ride that matter are the parts where I'm going hard (i.e., trying to max out my power output over a specific time duration). When I'm pedaling easy, I don't think I need a computer analysis to tell me how easy I'm pedaling.

As to your suggestion to get a coach experienced in the use of PMs, I may do that if I decide to race again. Right now, I'm just trying to earn the right to call myself a cyclist again. I've lost 22 pounds in two months just from riding regularly and I feel like I'll lose another 15 pounds before I settle into a riding weight. I think my body changes will continue for a couple more months, not a carefully managed change but just the result of 14 hours a week on the bike and eating a healthy diet. My decision to race again won't come for at least several months and my first race will be maybe a year from now. By then, anybody who calls himself a cycling coach will be experienced with training cyclists riding with PMs. I believe PMs will rapidly become (if not already) just a standard component of serious cyclists' bikes, in the same way HR and cadence computers have become standard components. I'm actually more interested in reading the scientific journals about exercise physiology and training effects, how and why the body develops strength and endurance. Any suggestions for my reading list?

One more thing. You didn't respond to my previous question about creating your personal MP/Endurance curve. Have you done this and what benchmarks did you use?

jws

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/

RapDaddyo

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

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.

__________________
MSc (Applied Sport and Exercise Science)
RST Associate Coach
ABCC Level 3 Coach
Doctoral Student (Physiology), University of Oxford, UK.
www.cyclecoach.com
www.science4sport.com

n crowley

[QUOTE=biker-linz]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

I didn't say 'most effective smooth pedalling techniqe', what I said was 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 tit-for-tat about it (I'm way too busy).
L.

__________________
MSc (Applied Sport and Exercise Science)
RST Associate Coach
ABCC Level 3 Coach
Doctoral Student (Physiology), University of Oxford, UK.
www.cyclecoach.com
www.science4sport.com

beerco

[QUOTE=n crowleyThe 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. [/QUOTE]

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.[/QUOTE]




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

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?

__________________
http://www.cyclecoach.com

RapDaddyo

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

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

__________________
MSc (Applied Sport and Exercise Science)
RST Associate Coach
ABCC Level 3 Coach
Doctoral Student (Physiology), University of Oxford, UK.
www.cyclecoach.com
www.science4sport.com