What determines efficiency ???

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I also have problems with the "LT" concept and generally avoid its use. Certainly Coyle did not find any strong correlation to lactate levels and hour power, just a slight postive one.

With all due respect, I think you need to go re-read Ed's paper: the correlation between power at LT and "hour power" was >0.9.

(Reading between the lines a bit, it also appears to me that you don't fully understand the LT concept, the essential essence of which is widely accepted in the field of exercise physiology.)

a 0.9 correlation is very high. I believe that the LT concept will be changing in several years. LT is widely accepted among the whole scientific community, although the discrepances at which blood lactate concentration is achieved are many and a reason of lots of discrepancy among scientific community. In my modest opinion an LT is an assumption of a metabolic/physiological status. Same as other concepts we have in physiology like RER (Respiratory Exchange Ratio) or VO2, which although are assumtions as well, they are highly accpeted.

The study by Coyle on the correlation between LT and "hour power" is quite high and therefore very plausible.

With all due respect, I think you need to go re-read Ed's paper: the correlation between power at LT and "hour power" was >0.9.

(Reading between the lines a bit, it also appears to me that you don't fully understand the LT concept, the essential essence of which is widely accepted in the field of exercise physiology.)Sorry, I was not being clear. I merely meant the correlation between absolute lactate levels and hour power. Moreover, I was being very broad in my use of the term "concept", here applying again only to absolute levels and the notion that low lactate levels are a necessarily a good thing.

Regarding fixed LT as a percent VO2, that is obvious. Again my appologies for poor wording, it was late.

More specifically, through what mechanism/ biological adaptions does efficiency increase in response to training? What contributes to differing efficiencies in different athletes at similar work levels ???

Biological adaption (in broad general terms):

Aerobic (with proper training) 2 to 4 years to peak

Anaerobic (with proper training but no increase in muscle mass) 3 months

Biomechanical efficiency (with proper training) continues to improve the longer you do it.

Thanks for the great information.

Regarding the adaptions that occur at the celluar level, I was being way too reductionist in seeing an intracelluar mechanism for the adaption- I actually think it is incorrect to treat individual cells as if they are organisms, they exist and operate only in the context or organs and organisms.

So in this context hormone levels determined externally from an individual cell will effect its internal operation. If I understand your post and the general science correctly, then it seems that this is a major pathway for adaptions that occur inside myocites.

In other words, celluar chemistry and architecture, such as mitochondrail development and density will be influinced from the start of a myocites life as a result of external influences in the form of hormones.

Regarding the biomechanical aspect of efficiency, I was not referring to changes which reduce the amount of work needed to attain a given speed, such as aerodynamic improvement. I am referring to the changes that occur as a result of saddle position, crank length, cadence etc.

Although external work cannot be independent of internal work, I think that less than ideal patterns of force application may lead to reductions in efficiency through the 'over-stressing' of individual fibres at certain points in the pedal stroke, which may lead to comparatively unecessary recruitment of type 2 fibres, or the result of what can only be termed as "localised anaerobic metabolism" as a result of insufficient blood supply to individual fibres in the context of an otherwise net aerobic state.

This may occur say in the context of ones saddle being way too low, which will increase greatly the demands on the quadricepts at the top of the pedel stroke.












Sorry about answering back to the post. I have been pretty busy this week (testing time!..everyone wants to get ready for the season!).
Thanks for the link!. Very interesting!.
The paper is based on cycling efficiency which according to Donovan and Brooks is a measure of the body's effectiveness in converting energy from nutrients into external work. However I believe we can qualify efficiency in more different ways, although the effectiviness in utilizing fuels (CHO and FAT) is extremely important. But efficiency can also be as you point out related to biomechanical effectiviness. There could be important changes in cycling efficiency depending on the bike position, especially during time trials. Also Cycling efficiency could be the ability of oxidize (wash out) lactate and therefore accumulate less lactate in muscle and blood.

I believe you adress very good and challenging questions.
At the cellular level there seem to be more events happening as well as adaptations other than just mitochondrial density increases or fiber type composition. I believe the short-life of myocites (muscle cells) could be changed despite of their short-life due to changes in mRNA expression (change of "factory pattern") in those cells. Other important changes are the increase in MTC´s (Metacarboxylate Transporters) for lactate. MCT1 are typical of Type I muscle fibers and responsible to transport lactate in those fibers. MCT4 are typically linked to more glycolytic fibers (Type IIa and IIb). This has to be with the cell-cell lactate shuttle proposed by Brooks. There is an increase in mRNA expression as well as MCT1-4 production in muscle fibers after a short period of adaptation to exercise, so you will have changes almost from the start.
On the other hand. we can find changes in isoform change of LDH (lactate Dehydrogenase) enzime, which is in charge of oxidizing lactate back to pyruvate as well as reducing pyruvate to lactate. LDH 1-2 are more typical of Type I fibers and tend to oxidize lactate into pyruvate and LDH 4-5 more typical of glucolytic fibers (Type IIa and IIb) and tend to reduce piruvate to lactate. It has been proposed an isoformic change in LDH 4-5 to LDH 1-2 in muscle fibers due to endurance training.

Another player is mLDH (mitochondrial LDH) which also regulates red-ox (reduction-oxidation) status inside the mitochondria and could have an important roll in oxidazing lactate to piruvate. Hashimoto, from Brooks group isolated and located in 2006 this enzime and showed the existance of this controversial mitochondrial enzyme.

On the other hand, there are also other important players like the hormonal adaptations which could cause very profund effects in terms of fuel utilization and muscle fiber mRNA expression. GH (growth Hormone), IGF-1, Cortisol, Epinephrine (Adrenaline), testosterone...can play a very important roll in cycling efficiency, although we could talk for a very long time about this...as well as about the above:) .

Anyways, I believe that there are many different adaptations that could lead to cycling eficiency as well as different approaches of what we can andesrtand of cycling efficiency. When biomechanics talk about cycling efficiency they don´t talk about the cellular events occuring. They talk about the many different biomechanical approaches towards reaching a correct position to increse cycling efficiency and I believe they are right. I have seen at the wind tunnel, for example, dramatic improvements in "cycling efficiency" by changing positions.

Cheers.

Great topic. I decided to join and ask few questions.

Andy, I tend to agree (in general) with your characterization of Coyle’s study.

One thing bothers me though. Why wouldn’t Coyle use Armstrong’s muscle biopsy to directly verify his hypothesis about efficiency increase. It should be simple enough and is a standard and reliable method.

If there was any fiber type change over a study period, he would be able to show it directly as supportive of his main hypothesis.

He also mentioned that hypoxic/altitude simulation practice could have been responsible for the efficiency changes. Yet there was no hematological data as to RBC mass, hct and so on.

Dr. Coggan is right about mysosin expresion. It could happen in just a matter of weeks. I endorse pretty much what Dr. Coggan said.

I have only look at Luttrel´s abstract and see that the study has several drwabacks:
1. The n (number) is very low.
2. There are no statistical significant differences
3. There is no biochemical/histological data.


As Coggan said, it is feasible to improve efficiency even long after your VO2max and LT have reached a plateau. I see that ALL the time with professional cyclists. As he said, an additive accumulation in kilometers year after year after year will lead to dramatical changes. I have seen more than 10% increases in efficiencies in pros I have followed throught years. Actually that is quite common...Anyone working with pros could tell you.


I also would like to say that very few cyclist train so well and so smart as Armstrong did. I have worked with 5 Pro Tour teams (well, 2 Pro Tour teams since Pro Tour birth and 3 former Cat 1 Pro Teams) and I have seen and tested hundreds of cyclists and as a guess, and it is a bit of a shame, about 75% of pro cyclists, in my opinion, don´t train well, or at least near as well as Armstrong did. On top of that we have to considered that Armstrong was already a genetically gifted cyclist before cancer. I have argued many times over this issue with many pro cyclists who where linking Armtrong´s amazing improvement in performance to drugs. I always argued to them that at the age of 21 y.o. Lance was already world champion in one of the toughest WC in the last years with Riis and Indurain behind him. I always asked cyclists to name me how many cyclists nowadays can be a WC at the age of 21??. I can´t think of any name, neither they do....then most pros just won´t continue arguing...
Also Armstrong lost about 7Kg of upper muscle mass wich it is just huge and probably only possible due to an extreme catabolism caused by cancer (isn´t that ironic?).

On the other hand I believe that there has been a lack of talented cyclists, both physiological and psychologically speaking, during Armstrong´s era which have made him his way to win the tour just easier. I have tested 3 TdF podium riders accompaining Armstrong at the podium during his 7 tour wins and although they may get mad at me, and they have very good physiological potential, I was not that impressed by their intelligence and the way they trained... (defenetely and by far near as smart and good as Lance) and I am sure that he would have won 2007´s TdF if he wanted as well since, in my opinion has probably been the TdF with the lowest level in the last decade. Lance was not only the best gifted cyclist, but the smartest at knowing his physiology as well. He pretty much did not need a coach because he knew more about coaching than most coaches.

About Coyle´s study about Lance evolution why not doing it on such an amazing cyclist like Armstrong?. I think it is really plausible. If others publish simple papers with college students...why not a paper about the evolution of one of the greatest cyclists of all times?.
As Coggan said, there is not much data published with world class cyclists...in part due to the lack of time to publish that people working with world class athletes have (:( ). Believe me, it is frentic out there working with the pros...

About inprovements in efficiency I would like to add changes at the cellular level, not only about fiber type composition. There are important events, regardless of fiber type composition, occuring at the cellular level and independent of oxygen uptake. It brings up to my mind the "controversial" lactate shuttle mechanisms proposed by Brooks, both cell-cell and intracellular lactate shuttles. I believe that many of the adaptations at the cellular level go in that direction as well as in changes in fiber type composition and energy fuel utilisation and economy.

A few comments. First, regarding the Luttrell study. You are wrong. The study did find statistically significant differences both within and between groups especially as regards efficiency. While the n may seem low, it was large enough to reach statistical significance. That means it is as strong a study as one with a million participants that reaches the same statistical significance. The fact that he did not get biochemical or histological data is of no concern as he was not trying to determine mechanism but, rather, simply see if training in this "unorthodox" fashion resulted in training differences/improvements. Now that the differences have been shown it is up to subsequent research to ask the question, Why?

Next, some of your comments seem to contradict each other.

You state that no one was smarter in training than Armstrong but you also say such efficiency improvements as seen by Armstrong occur in professional cyclists all the time. Since the efficiency improvement was the only metric that changed in Armstrong over the 8 years it would seem then that one doesn't have to be smart, like Armstrong, to see those differences. So, what is it that makes you think Armstrong was so much smarter than the rest of the pack?

You write: "I have seen more than 10% increases in efficiencies in pros I have followed throught years. Actually that is quite common...Anyone working with pros could tell you." If only you could provide some documentation or a reference to back up that statement. And, then if you could provide the documentation that these efficiency changes are due to muscle fibre type changes in these cyclists. I look forward to seeing that.

The issue regarding this debate, from my perspective, is not whether the data on Armstrong is interesting and valuable but how can one best explain the data, especially the efficiency changes seen. I simply believe there is more than one way to explain it, Coggan believes there is only one plausible way.

Biological adaption (in broad general terms):

Aerobic (with proper training) 2 to 4 years to peak

Anaerobic (with proper training but no increase in muscle mass) 3 months

Biomechanical efficiency (with proper training) continues to improve the longer you do it.

According to some here it is not possible to improve biomechanical efficiency. How do you propose one can improve biomechanical efficiency "(with proper training)" over time.

http://www.sff.net/people/hmm/images/popcorn.gif

According to some here it is not possible to improve biomechanical efficiency. How do you propose one can improve biomechanical efficiency "(with proper training)" over time.

I don't have any studies to fall back on, it is a common enough understanding that biomechanical efficiency continues to improve the longer you do a thing. The problem is that ones ability to recover from training stimulus diminishes with age and training volume/intensity and levels of fitness can not be maintained.

However biomechanical efficiency is there !

I wonder if anyone has done a calorie expenditure comparison ?

I think all of you are confused about biomechanical efficiency in training.

Biomechanical efficiency is what he body does to be more calorie expenditure efficient. It happens over longish periods of time of doing exactly the same thing. So good training that is varied and has excellent training stimulus may actually slow down the natural biomechanical efficiency that occurs. Thing is you just need to be faster, stronger, able endure, if you are not as biomechanical efficient as you could be, the only thing you can do to improve it is be at it for a few more years !

A few comments. First, regarding the Luttrell study. You are wrong. The study did find statistically significant differences both within and between groups especially as regards efficiency. While the n may seem low, it was large enough to reach statistical significance. That means it is as strong a study as one with a million participants that reaches the same statistical significance. The fact that he did not get biochemical or histological data is of no concern as he was not trying to determine mechanism but, rather, simply see if training in this "unorthodox" fashion resulted in training differences/improvements. Now that the differences have been shown it is up to subsequent research to ask the question, Why?

Next, some of your comments seem to contradict each other.

You state that no one was smarter in training than Armstrong but you also say such efficiency improvements as seen by Armstrong occur in professional cyclists all the time. Since the efficiency improvement was the only metric that changed in Armstrong over the 8 years it would seem then that one doesn't have to be smart, like Armstrong, to see those differences. So, what is it that makes you think Armstrong was so much smarter than the rest of the pack?

You write: "I have seen more than 10% increases in efficiencies in pros I have followed throught years. Actually that is quite common...Anyone working with pros could tell you." If only you could provide some documentation or a reference to back up that statement. And, then if you could provide the documentation that these efficiency changes are due to muscle fibre type changes in these cyclists. I look forward to seeing that.

The issue regarding this debate, from my perspective, is not whether the data on Armstrong is interesting and valuable but how can one best explain the data, especially the efficiency changes seen. I simply believe there is more than one way to explain it, Coggan believes there is only one plausible way.
About Lutrell study, I only read the abstract, since I am not subscribed to that journal. I did not read therefore the whole study but in the abstract there are no statistical significancies expressed. There are no p´s, which usually are expressed in the abstract. Taken into account that the differences are 23.6 vs 21.3% and 23.9 vs 21% at 45 and 60 min respectively and with such a low n It is hard to imagine that you are going to have a statistically significant difference of at least P< 0.05. However, I would love to see the statistics you mention.

I don´t see why you percieve that I contradict myself with my comments. To me Armstrong if not the smartest was one of the smartest guys training on top of being genetically gifted and NO, I did not mention that such efficiency improvements occur in the rest of the riders as you wrongly misunderstand. I meant that you see improvements in efficiency in pretty much all professionals, some more some less but pretty much they all improve after they turn Pro during their career. As training, kilometers and competition builds up year after year they MUST improve, the same way that a CAt 5 rider SHOULD improve after 8 years of racing and AT least turn Cat 4...Or the same way that throughout high school we all improve (some more, some less) in our skills along the years. That does not mean that we all improve the same way since there will be allways smarter people that others as well as hard workers.

About what makes Lance smarter than the rest of the pack?. MANY things!. While many (not all, though, eh?) riders in the winter pile up on beer he spent long sessions training already for the season. He spent 1 week at the wind tunnel almost every year traying new products and new equipment, when the few professionals who go to wind tunnel spend an average of 4h. His improvements in the wind tunnel were impressive (I can´t tell you how much but really impressive). He relayed on the Science of training (not Carmichael necessarely) more than the rest. He was obssesive with all the smallest details compared to his peers and he woked harder than most of the cyclists that I know. If on top of that if you put together that he was genetically gifted and battled a cancer Iy makes perfect sense to me how he oustanded his generation. On top of that As I mentioned I was not impressed by the intelligence of many Top professionals who even got to the TdF podium. I am sure that at least 1 of them I know who was TdF podium if he had been as smart as Lance he could have beaten him...

To me it is irrelevant to even try to study that a professional cyclist can increase a 10% throughout his/her career since it is pretty logical and obvious in terms of metabolic and physiological efficiency. This, to me, is like trying to prove that a student in High school improves his/her skills a 10% during the whole process of education...It is not only irrelevant but pretty obvious. To me it is an irrelevant study, scientifically speaking and even irrelevant in terms of general media since it does not take a rocket scientist to see this.

I agree that there are more than one way to explain the improvements of efficiency since there are, to me, several perspectives and approaches to describe efficiency.

I am not traying to blow up your study nor your product since I know pros who have used your product. Some said it helped some it did not, although maybe they did not train right or had the patience.....

Cheers

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well said Alex. I concur :D .

About Lutrell study, I only read the abstract, since I am not subscribed to that journal. I did not read therefore the whole study but in the abstract there are no statistical significancies expressed. There are no p´s, which usually are expressed in the abstract. Taken into account that the differences are 23.6 vs 21.3% and 23.9 vs 21% at 45 and 60 min respectively and with such a low n It is hard to imagine that you are going to have a statistically significant difference of at least P< 0.05. However, I would love to see the statistics you mention.

I don´t see why you percieve that I contradict myself with my comments. To me Armstrong if not the smartest was one of the smartest guys training on top of being genetically gifted and NO, I did not mention that such efficiency improvements occur in the rest of the riders as you wrongly misunderstand. I meant that you see improvements in efficiency in pretty much all professionals, some more some less but pretty much they all improve after they turn Pro during their career. As training, kilometers and competition builds up year after year they MUST improve, the same way that a CAt 5 rider SHOULD improve after 8 years of racing and AT least turn Cat 4...Or the same way that throughout high school we all improve (some more, some less) in our skills along the years. That does not mean that we all improve the same way since there will be allways smarter people that others as well as hard workers.

About what makes Lance smarter than the rest of the pack?. MANY things!. While many (not all, though, eh?) riders in the winter pile up on beer he spent long sessions training already for the season. He spent 1 week at the wind tunnel almost every year traying new products and new equipment, when the few professionals who go to wind tunnel spend an average of 4h. His improvements in the wind tunnel were impressive (I can´t tell you how much but really impressive). He relayed on the Science of training (not Carmichael necessarely) more than the rest. He was obssesive with all the smallest details compared to his peers and he woked harder than most of the cyclists that I know. If on top of that if you put together that he was genetically gifted and battled a cancer Iy makes perfect sense to me how he oustanded his generation. On top of that As I mentioned I was not impressed by the intelligence of many Top professionals who even got to the TdF podium. I am sure that at least 1 of them I know who was TdF podium if he had been as smart as Lance he could have beaten him...

To me it is irrelevant to even try to study that a professional cyclist can increase a 10% throughout his/her career since it is pretty logical and obvious in terms of metabolic and physiological efficiency. This, to me, is like trying to prove that a student in High school improves his/her skills a 10% during the whole process of education...It is not only irrelevant but pretty obvious. To me it is an irrelevant study, scientifically speaking and even irrelevant in terms of general media since it does not take a rocket scientist to see this.

I agree that there are more than one way to explain the improvements of efficiency since there are, to me, several perspectives and approaches to describe efficiency.

I am not traying to blow up your study nor your product since I know pros who have used your product. Some said it helped some it did not, although maybe they did not train right or had the patience.....

Cheers
Thanks for the response. In the Luttrell abstract he did mention the differences in GE and HR were "significantly higher" and "significantly lower". I guess they presumed people would know that this meant they reached the 0.05 standard, without stating so specifically.

It also seems to me that we might be having a language problem here. It seems to me that when you say that professionals improve their efficiency with time I would say they are improving their effectiveness or ability with time. To me, efficiency is a specific term that refers to how much power the rider is generating compared to how much energy they are burning. As near as I can tell, there are only two studies out there that have documented cycling efficiency improvements with training over time, those being the Coyle study on Lance and the Luttrell study comparing training with PowerCranks to regular cranks.

Once it is known that cycling efficiency can be improved it seems to me that those involved in training these athletes would want to know what is necessary to achieve these improvements. Seems to me the problem with both the Coyle and the Luttrell study is there is not enough information to answer the question as to how these improvements occurred in these two instances. People who say they know what actually occurred in these two instances are simply guessing.

I don't doubt that Lance was much smarter than everyone else. I still take some exception to your statement that you believe that everyone at the top pro level will improve efficiency 10% over the years, if they just keep training. (As I said above, I would say they continue to improve their effectiveness or abilities, not necessarily their efficiency.) I don't believe there is any evidence to support that view, other than the Coyle study, which is an anecdotal report so we do not know if it applies to the others. And, even if it did, we cannot know the basis of the improvement from that report.

Thanks for the response. In the Luttrell abstract he did mention the differences in GE and HR were "significantly higher" and "significantly lower". I guess they presumed people would know that this meant they reached the 0.05 standard, without stating so specifically.

It also seems to me that we might be having a language problem here. It seems to me that when you say that professionals improve their efficiency with time I would say they are improving their effectiveness or ability with time. To me, efficiency is a specific term that refers to how much power the rider is generating compared to how much energy they are burning. As near as I can tell, there are only two studies out there that have documented cycling efficiency improvements with training over time, those being the Coyle study on Lance and the Luttrell study comparing training with PowerCranks to regular cranks.

Once it is known that cycling efficiency can be improved it seems to me that those involved in training these athletes would want to know what is necessary to achieve these improvements. Seems to me the problem with both the Coyle and the Luttrell study is there is not enough information to answer the question as to how these improvements occurred in these two instances. People who say they know what actually occurred in these two instances are simply guessing.

I don't doubt that Lance was much smarter than everyone else. I still take some exception to your statement that you believe that everyone at the top pro level will improve efficiency 10% over the years, if they just keep training. (As I said above, I would say they continue to improve their effectiveness or abilities, not necessarily their efficiency.) I don't believe there is any evidence to support that view, other than the Coyle study, which is an anecdotal report so we do not know if it applies to the others. And, even if it did, we cannot know the basis of the improvement from that report.Thanks for your response. Well, I believe than more than a lenguage problem it is a deffinition problem of what efficiency is. Luttell study talks about Gross Efficiency but there are several types of efficiencies defined and even some more could be in there, I believe, but the most used are:

1 ) Gross efficiency: the ratio of the work accomplished to energy expended, that is, the effectiveness of converting chemical energy into mechanical work.

2) Net efficiency: the ratio of the work accomplished to the energy expended above that during rest, that is, the cost of resting metabolism is subtracted from the denominator in the computation

3) Work efficiency: the ratio of the work accomplished to the energy expended above that during cycling with no load, calculated by subtracting from the denominator the cost of moving the legs plus the resting metabolism

4) Delta efficiency : the ratio of the change in the power output to the change in the energy expended at each power output.

In my opinion Delta efficiency is the one that could best describe muscle efficiency in cycling. I have analyzed many tests of cyclists and looking at Gross efficiency I have seen things that do not make much sense in terms of physiological capacities related to lactate accumulation as well as "real performances" on the road. However as none of these definitions are "dogmas" I believe we should be open to even more speculations, especially when, as you point out, there is not much data about cycling efficiency improvements. The data obteined for these definitions are throughout indirect calorimetry, which is an indirect measurement and therefore could be subject to some assumptions that could not be necessarely right (my opinion). We could even be open to muscular efficiency based on lactate production and removal, which to me (by my empiric observations) is by far more accurate than indirect calorimetric measurements.

I would also like to read about the subjects used in Luttell´s study since as you very well know "powercranks" and skills are very well related, since PC´s are hard to get used to. With such a low n we could make an assumption that the Powercrank group had better skills at them and therefore improved their GE better (?), something we don´t know.

About effectiviness and efficiency...with so many definitions on top of the other "possible" ones, it all comes down to effectiviness to produce work at a lower metabolic cost right?. So it all comes to effectiviness...call it or define it as you want...If I go up Le Tourmalet in 45min and next year I go up in 33 my effectiviness would had changed dramatically due to...whatever the definitions above or others may be...but the fact is that I would have reduced 12 min my time which is far more than a 10% improvement.
From the applied point of view, to me that is efficiency or effectiviness, whichever term you want to use.

However, I believe that this is an interesting and challenging post due to the luck of studies done on pro cyclists and histochemical (cellular) studies on this. On the other hand it will be a bit of an "utopia" ask a world class cyclist to get biopsies year after year or every so often because they would not like to volunteer...and if any does..Please contact me!!.

Thanks for your response. Well, I believe than more than a lenguage problem it is a deffinition problem of what efficiency is. Luttell study talks about Gross Efficiency but there are several types of efficiencies defined and even some more could be in there, I believe, but the most used are:



I would also like to read about the subjects used in Luttell´s study since as you very well know "powercranks" and skills are very well related, since PC´s are hard to get used to. With such a low n we could make an assumption that the Powercrank group had better skills at them and therefore improved their GE better (?), something we don´t know.

About effectiviness and efficiency...with so many definitions on top of the other "possible" ones, it all comes down to effectiviness to produce work at a lower metabolic cost right?. So it all comes to effectiviness...call it or define it as you want...If I go up Le Tourmalet in 45min and next year I go up in 33 my effectiviness would had changed dramatically due to...whatever the definitions above or others may be...but the fact is that I would have reduced 12 min my time which is far more than a 10% improvement.
From the applied point of view, to me that is efficiency or effectiviness, whichever term you want to use.

However, I believe that this is an interesting and challenging post due to the luck of studies done on pro cyclists and histochemical (cellular) studies on this. On the other hand it will be a bit of an "utopia" ask a world class cyclist to get biopsies year after year or every so often because they would not like to volunteer...and if any does..Please contact me!!.Here is the description of Luttrel's subjects: Twelve healthy, physically active cyclists (10 men, 2 women) volunteered for the study. The inclusion criteria for participation in the study were: (a) participated in at least 3 cycling events, including triathlons or duathlons, in the past 12 months; (b) cycling >= 2 d/wk as part of a current training regimen; and (c) no use of ergogenic aids or prescribed medication during the study.

The stated purpose of the study, in part, was put forward thusly: "To date, no published study has validated the effectiveness of PowerCranks for improving VO2max, AT, or cycling efficiency. Because the Powercranks are designed for training purposes only, it is important to investigate whether any early phase physiological adaptation might occur after utilizing this device. Therefore, the purpose of this study was to compare the effects of 6 weeks of training with PowerCranks to a control group training with normal bicycle cranks on ..."

Anyhow, regarding the use of the different terms like efficiency or effectiveness, etc. I think it is important that we all be using the terms in the same way (same definitions) so we communicate more clearly and effectively, more "efficiently" if you like. :-)

Thanks for your response. Well, I believe than more than a lenguage problem it is a deffinition problem of what efficiency is.

1 ) Gross efficiency: the ratio of the work accomplished to energy expended, that is, the effectiveness of converting chemical energy into mechanical work.

2) Net efficiency: the ratio of the work accomplished to the energy expended above that during rest, that is, the cost of resting metabolism is subtracted from the denominator in the computation

3) Work efficiency: the ratio of the work accomplished to the energy expended above that during cycling with no load, calculated by subtracting from the denominator the cost of moving the legs plus the resting metabolism

4) Delta efficiency : the ratio of the change in the power output to the change in the energy expended at each power output.
.

Just read the article on the link Alex posted, good read, And it occurred to me there is an other type of efficiency

(5) Smarts : the ability to know how hard to work/not to work to achieve a result.

And the smartest thing Lance did was to choose his parents well !

Here is the description of Luttrel's subjects: Twelve healthy, physically active cyclists (10 men, 2 women) volunteered for the study. The inclusion criteria for participation in the study were: (a) participated in at least 3 cycling events, including triathlons or duathlons, in the past 12 months; (b) cycling >= 2 d/wk as part of a current training regimen; and (c) no use of ergogenic aids or prescribed medication during the study.

The stated purpose of the study, in part, was put forward thusly: "To date, no published study has validated the effectiveness of PowerCranks for improving VO2max, AT, or cycling efficiency. Because the Powercranks are designed for training purposes only, it is important to investigate whether any early phase physiological adaptation might occur after utilizing this device. Therefore, the purpose of this study was to compare the effects of 6 weeks of training with PowerCranks to a control group training with normal bicycle cranks on ..."

Anyhow, regarding the use of the different terms like efficiency or effectiveness, etc. I think it is important that we all be using the terms in the same way (same definitions) so we communicate more clearly and effectively, more "efficiently" if you like. :-)
Thanks for the info. To tell you the truth, when Powercranks came out I was very interested since I heard some cyclists were happy with the results. However with so many things going on it has been difficult to keep up.

Just read the article on the link Alex posted, good read, And it occurred to me there is an other type of efficiency

(5) Smarts : the ability to know how hard to work/not to work to achieve a result.

And the smartest thing Lance did was to choose his parents well !
Good point. Many Pros out there meet so many physiological requirements but only a few meet the psychological requirements as well.

About Lance genetic make up, I would blame it on more on His mother. Just for fun, did you know that Mitochondria genetical make up comes from the mother?.

Thanks for the info. To tell you the truth, when Powercranks came out I was very interested since I heard some cyclists were happy with the results. However with so many things going on it has been difficult to keep up.How refreshing, especially for this site, that you might actually have an intellectual curiosity as to whether they might be useful as opposed to thinking this is a closed issue and such a device can be of zero usefulness (or actually interfere with "real" training).

It is also refreshing to hear from someone who should know how difficult it is to study elite athletes. Some here seem to think that within a year or so of coming up with PowerCranks it should have been a "simple" task for me to take the top 10 finishers of the TDF, randomly put them in two groups, one on PC's and the other not, and test them weekly for 6 months so I could "prove" my outlandish claims. My having failed to do so (or something similar) is proof that my product is nothing but hype.

Thanks for a breath of fresh aire.