I like they way your second sentence directly contradicts the first. If optimizing glycogen usage were important, we would ride at the most efficient cadence to wring every bit of power out of each unit of glycogen we could. As noted above that would be around 55-60 rpm. The you say that fast experienced riders are further from this goal than average. Nice.

Nope. I don't care either. Why do you care what your efficiency is? I just want to increase the amount of power I can put out over a given period. If I happen to be inefficient I'll eat more.

Portable metabolic cart? But why insist on measuring it out on the road. Efficiency is constant enough that there won't be any change between what's measured in a lab and what's exhibited on the road.

I suspect that word you keep using, efficiency, does not mean what you think it means.

Yeeesh. Eh? How much glycogen do you have? Or maybe you're just used to doing short rides. LD riders need to never run out of it. Meaning they hate using it at all, if they can help it, because it's slow putting it back. There's a delicious meal known as "fried rabbit," that we frequently partake of.

You're just being negative to be nasty. You should get out more. I know you're smarter than that.

When I say a word, it means exactly what I say it means!

In this case, I mean efficient in terms of finishing the ride in style. If you want it to mean efficient in terms of fuel to joules conversion ratios, you have my permission. I just don't see how knowing this relatively unchanging number is going to get you in the break. The idea of tactical riding is that one modifies one's behavior on the road in order to effect the probability of one participating in that break. If you're not tired when the break goes, you've been riding efficiently. I don't think there's any disagreement in the cycling community about that use of that word in that sense.

So say you're riding along and you find a position, either on the bike or in the pack, that allows you to ride at the same speed and 10 beats lower, I'd say you're being more efficient. You're covering the same miles with less effort. If one used power, one would use watts to determine the same thing. Auto manufacturers go to great lengths to build cars which are more fuel efficient, even though the explosive power in fuel is not under their control.

Unlike Sick, I can't imagine why one would not want to have a device for measuring efficiency.

I think you'll give me the above. And given that, why wouldn't one strive to go faster on the road, solo? Most folks need some measurement devices to help them with that, I think you'll agree. What do these devices do, if not help the rider ride more efficiently? One can't say that they help the rider to go faster, because you don't need anything except a speedometer for that, since the object would be to go as fast as possible. Unfortunately, as fast as possible doesn't last very long. Hence, conservation is the name of the game, and conserving another way of saying efficient.

The problem is that a lower heart rate does not mean you are more efficient, even using your own definition. Because a lower cadence lowers cardiovascular demand at the expense of muscular demand. Which means your HR won't be as high but your muscles will be more worn out. Mashing in a big gear up a climb may not stress your heart much but it will thrash your legs.

Well, yeah! I seem to recall saying some of these same things in several different ways in this discussion. But one can put this another way, too, from the asgelle perspective. When we breathe, the O2 runs the aerobic cycle, which produces energy. In a steady state aerobic system, we can measure increase or decrease of energy production by O2 use. So producing more potential energy with less energy use would also be efficiency, would it not? And would not your HRM combined with your cyclocomputer give you this information? Or better yet, HRM and power meter?

But it's up to you how you use this information. As I discussed earlier, each rider will home in on a preferred cadence for a particular task. Might be less efficient in one sense and more in another. HRM is still a handy tool. If it wasn't much use, no one would use one.

We can keep playing "define your terms," if you like. But there are many different efficiencies, and many ways to, if not measure them, at least get a comparative handle on them in the field. It's great that you guys have lab and wind tunnel access. I have to use the tools I carry with me.

But you seemed to be saying before that a lower HR somehow indicates or proves that one is being more efficient.

The problem is you have implied that efficiency changes with cadence and that having a lower HR means you're pedalling more efficiently. The reality is a lower HR just means you're putting out less power; you're not more efficient you're just not working as hard.

"Effect of cycling position on oxygen uptake and preferred cadence in trained cyclists during hill climbing at various power outputs " Chris Harnish , Deborah King and Tom Swensen concludes: "These data support the premise that trained cyclists are equally economical using high or low cadences, but may face a limit to benefits gained with increasing cadence."

Well that certainly explains your problem with communication.

It would not. I don't see how potential energy relates to finishing in style (to use your definition) and it certainly isn't the only form of energy considered in the correct one.

And I think I just said it again in the post you seem to be replying to. Not just "seemed to be saying". I said it.

But then you also seemed to agree when I said:

"The problem is that a lower heart rate does not mean you are more efficient, even using your own definition. Because a lower cadence lowers cardiovascular demand at the expense of muscular demand. Which means your HR won't be as high but your muscles will be more worn out. Mashing in a big gear up a climb may not stress your heart much but it will thrash your legs."

You can't have it both ways.

Have we abandoned physics now, too, along with our HRMs? If you have a mountaintop finish, potential energy is the goal. And the quicker one can have it, the better. I think they say that the person who acquires it the fastest "wins."

The whole notion of efficiency is to have a good ratio in the conversion from one form of energy to another. If you're denying that now, too, I think this discussion has reached its limit.

I agreed with your last two sentences, because in them you confirmed, from your personal experience, exactly what I've been saying all along. Lower cadence lowers cardiovascular demand. Yes. That means that your conversion ratio from one form of energy to another is more efficient. The fact that it thrashes your legs means you will not use it except in training, because it is a less efficient means of attaining your goal. It cuts both ways. You can't have it just one way.

And that certainly explains how your reading might not have gotten as far as children's books, or perhaps those memories were lost along with your sense of humor.

But lower cardiovascular demand does not mean you are more "efficient" in any way other than less hearbeats. The stress on your body is higher, you won't be able to ride as far or as long and you will be more tired from the effort. If you were climbing in a race and there was an attack you would be less able to respond.

Good grief! I can't believe I'm hearing this. The whole point of using a power meter is that HR is not a reliable indicator of power output. Lower HR may mean you are putting out less power, or then again, it may not.

I still don't see why you don't just put your power meter equipped bike on your rollers or trainer, put on your transmitter belt, and experiment yourself! You'll see immediately that I'm right. Spin a 70 cadence at a particular power, say 100 watts to make it obvious, and then at 95 cadence at the same power. Watch your HRM. Report the difference. I challenge you to do this, though I don't think you will.

"not working as hard" to put the same power to the road is certainly a good definition of efficiency. I don't see how you can argue with that.

Because lower HR does not mean you are not working as hard!

Which is precicely the reason power meters are better than HRMs!

Here's the complete abstract:

"Abstract Numerous researchers have studied the physiological responses to seated and standing cycling, but actual field data are sparse. One open issue is the preferred cadence of trained cyclists while hill climbing. The purpose of this study, therefore, was to examine the affect of cycling position on economy and preferred cadence in trained cyclists while they climbed a moderate grade hill at various power outputs. Eight trained cyclists (25.8 ± 7.2 years, http://www.bikeforums.net/content/42...rticleIEq1.gif 68.8 ± 5.0 ml kg−1 min−1, peak power 407.6 ± 69.0 W) completed a seated and standing hill climb at approximately 50, 65 and 75% of peak power output (PPO) in the order shown, although cycling position was randomized, i.e., half the cyclists stood or remained seat on their first trial at each power output. Cyclists also performed a maximal trial unrestricted by position. Heart rate, power output, and cadence were measured continuously with a power tap; ventilation Ve', BF and cadence were significantly higher with seated climbing at all intensities; there were no other physiological differences between the climbing positions. These data support the premise that trained cyclists are equally economical using high or low cadences, but may face a limit to benefits gained with increasing cadence."

Since we don't have the full text of the study, it's a little hard to say what was actually studied. There is certainly no information in this abstract to confirm that individual cyclists were studied at more than one seated cadence at each power output, which is what you are implying with your selected quote.

Do you find breathing in a vacuum helps or hinders your performance?

That agrees with my (completely unscientific) personal experience. It also explains why I see people doing TT intervals at such low cadences (despite some articles I've read that advocate a high cadence for time trials). Do you have any references (scientific journals, e.g.) for this? I'd be interested to learn more.

Ooops -- shoulda read your more recent posting. I'll use Google Scholar to find more.

I'm not interested in my HR at 100W. I agree you would probably notice a difference in HR during essentially unloaded pedaling.

Here is a set of 5min intervals I did recently on a windy day. I didn't feel great and tried a few different cadences. As you can see my HR is reasonably correlated to power but completely uncorrelated to cadence which is consistent with the reference I posted.

http://i43.tinypic.com/2wr0xhl.jpg

I can send you the article if you want but here's another one for you to ponder: In Professional Road Cyclists, Low Pedaling
Cadences Are Less Efficient. I think the title is self explanatory but you can read the abstract for a more complete explanation.

Basically, all of these references confirm that at higher power outputs low cadence is not more efficient or economical. At low power outputs a low cadence has been shown to be more efficient.

Greg: Not much doubt about that one. Nice study. At high power, most pro riders definitely prefer a high cadence in the lab. At low power, as you say, low cadence is more efficient. So there must be some curve or series of curves, connecting duffers and pros, low power and high power, the shape of which is yet to be defined?

I went out in the shop and did a little test on my rollers, set up with fluid resistance. I warmed up and then pedaled at several cadences, all at 20 mph. I repeated the test series to make certain that I wasn't getting a variation due simply to changing cadences. The cadences are odd because I held the speed constant at 20. I couldn't use really low cadences because I didn't have enough resistance. I chose 20 mph because that got my high gear cadence below 60. The HRs are about 4 beats lower than what I would see on the road at this speed because the fluid in my resistance unit is worn out. Here's what I got:
112 HR @ 59 cadence
113 HR @ 69 cadence
116 HR @ 82 cadence
122 HR @ 93 cadence

I would like to go out to my favorite interval hill and repeat this test at LT, just to see how I compare with the pros studied in greg's link. I know for sure that my GE will be lower at 100 cadence at LT than at 80 cadence. As I said, I don't have a power meter, but my LT power is probably down to about 200w, judging by my vertical/hr versus that of a pro.

I measured the cadence of some Tour greats while climbing seated. I took a look at Ullrich's famous Attack that Sick likes so much. Near as I can tell, Jan pedaled at between 60 and 85, high for him. On Landis' famous stage 17, both he and Sastre pedaled about 82 while seated. I timed Vino at 78 on Luz Ardiden. I didn't time anyone climbing at 100 except Lance, whom I timed at 100 on Brasstown Bald, and 83-96 on the Hautacam in 2000, where I timed Pantani at 70 and stage winner Ochoa at 57. So most of them don't pedal the way they're supposed to, either! In fact, they're closer to me than to the lab rats.

So maybe GE in the lab isn't the same as GE in the field. Or maybe these Tour riders just didn't know what they were doing.

None of which answers the question of why most pros prefer to climb at slower cadences, sometimes much slower, than they ride on the flat.

Looking at TT's, without getting too far into it, I see in '89 Lemond won with a mostly 85 cadence, while Fignon did a steady 90. Lance of course TTed at 100-110, and Contador similar, but most folks are closer to 90.

So none of that answers the question of why most pros also TT at non-optimal cadences according to the finest lab tests.

And none of that answers the question of why it's easier to go hard on a climb than on the flat, which is how all this started.

As most of us know, we use HR as a measure of how hard we are working because HR is proportional to VO2:
www.firstbeat.fi/files/VO2_Estimation.pdf

There are a number of different efficiencies, including Gross Efficiency (GE) which was measured in the paper linked to by greg, above, and defined here:
http://www.answers.com/topic/mechanical-efficiency