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Does cycling efficiency increase over time/with training/maturation?
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I've mentioned several times before that the data I have on myself is consistent with what Coyle reported for Armstrong, but have never shared the details, so thought this was as good a time and place as any...

First, a graph:



What's shown above is my interpolated VO2 (in L/min) at a power of 250 W, based on data culled from the 100+ incremental exercise tests that I have done over the years. I've chosen to present that data this way vs. giving the slope and intercept of the VO2-power relationship, and/or in terms of gross (or net) efficiency, just for simplicity's sake, but the way to read the graph is lower = more efficient.

To be included in the data set, I decided that the tests/data had to meet the following criteria:

1) metabolic cart validated against Douglas bags
2) stage duration >4 but <10 min
3) highest stage < ventilatory threshold
4) use of an electronically-braked ergometer

Like Coyle's paper, this is a retrospective case study, and therefore lacks the rigorous controls that you would want to see in careful scientific investigation. OTOH, the data were collected in "good faith", i.e., without any preconcieved notions as to what the outcome might be. Perhaps just as importantly, I know my way around VO2 measurements and metabolic carts quite well, having built/rebuilt/validated such systems at six different institutions over the years, and thus trust those data. In support of the belief that this is not a source of bias, my highest VO2max measured using three of the four systems used to collect the data included in the plot varied by <0.1 L/min, or <2%. I have less data on the accuracy/precision of the power data, but four of the six tests shown in the graph were conducted using the same Velodyne, which was validated against a carefully-calibrated SRM. Moreover, these tests are interspersed among the other, and although span a shorter period of time (i.e., 14 y, vs. 26 y for the entire dataset), show the same trend (i.e., over time, a reduction in VO2 at the same power).

Enjoy!!

EDIT: I was born in 1959, started cycling in 1974, and racing in 1975...data for the first test were therefore collected after I'd been training for 8 y, when I was 23. I did my first VO2max test in 1977, when I was 18, after one or more per year most years after that, but don't have submaximal data from before 1982.
Last edited by: Andrew Coggan: Sep 25, 08 8:39
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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Thanks for the data, congratulations on the improvement.

A couple of questions:

1. Were you the world champion in '82 when you did your first test?
2. Did you see an 8% efficiency improvement in 7 years?
3. Do you have serial muscle biopsy results that can fully account for this efficiency improvement?

I don't doubt that efficiency can improve with time but if all of those are not answered in the affirmative then your data is not fully consistent with Coyle and his conclusions. As you know, the issue I take with the Coyle paper is not with the improvements noted but in his explanation as to how the improvements he noted occurred.

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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Worthless pseudo-science garbage.

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The Triathlon Squad

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Re: Does cycling efficiency increase over time/with training/maturation? [Paulo Sousa] [ In reply to ]
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Worthless pseudo-science garbage.
Yet oddly enough, of higher quality than the hypothetical (and flawed) calculations you've feel worth putting up on your blog...
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Re: Does cycling efficiency increase over time/with training/maturation? [Frank Day] [ In reply to ]
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Thanks for the data, congratulations on the improvement.

A couple of questions:

1. Were you the world champion in '82 when you did your first test?
2. Did you see an 8% efficiency improvement in 7 years?
3. Do you have serial muscle biopsy results that can fully account for this efficiency improvement?

1. Irrelevant to the question at hand.

2. Slope is closer to 3%.

3. Nope. OTOH, I can tell you that I was >75% type I in my v. lateralis before the first measurements shown, which may explain why my efficiency hasn't improved as much as Armstrong's apparently did (i.e., a "ceiling effect").

In any case, we can definitely rule out one-legged pedaling drills or the use of PowerCranks...
Last edited by: Andrew Coggan: Sep 25, 08 9:43
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:
In Reply To:
Thanks for the data, congratulations on the improvement.

A couple of questions:

1. Were you the world champion in '82 when you did your first test?
2. Did you see an 8% efficiency improvement in 7 years?
3. Do you have serial muscle biopsy results that can fully account for this efficiency improvement?

1. Irrelevant to the question at hand.

2. Slope is closer to 3%.

3. Nope. OTOH, I can tell you that I was >75% type I in my v. lateralis before the first measurements shown, which may explain why my efficiency hasn't improved as much as Armstrong's apparently did (i.e., a "ceiling effect").

In any case, we can definitely rule out one-legged pedaling drills or the use of PowerCranks...
OTOH maybe you would have had MORE improvement with one legged drills or PCs.....

just sayin' ;-)

---

cat
Sponsored by Suntheanine, Lycored and Celadrin
http://www.lycored.com/web/content/library.asp http://suntheanine.com/Research.cfm http://celadrin.com/pages/studies.php
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:
In Reply To:
Thanks for the data, congratulations on the improvement.

A couple of questions:

1. Were you the world champion in '82 when you did your first test?
2. Did you see an 8% efficiency improvement in 7 years?
3. Do you have serial muscle biopsy results that can fully account for this efficiency improvement?

1. Irrelevant to the question at hand.

2. Slope is closer to 3%.

3. Nope. OTOH, I can tell you that I was >75% type I in my v. lateralis before the first measurements shown, which may explain why my efficiency hasn't improved as much as Armstrong's apparently did (i.e., a "ceiling effect").

In any case, we can definitely rule out one-legged pedaling drills or the use of PowerCranks...
1. is not irrelevant if we are discussing supporting the Coyle paper as it is unlikely that the current world champion is going to improve efficiency by simply training more with resulting marked change in muscle fibre type. That is what Coyle saw and then hypothesized.

Anyhow, it matters little if you used PC's or one-legged drills in seeing this improvement. You saw it. Now the question is how did it occur. You have zero data that would help answer that question, as did Coyle when he guessed at a mechanism in his paper.

Let's suppose your improvement did come about solely because you were able to change your fibre type to more efficient fibers, that still leaves open the question as to whether there are other ways that efficiency can be improved also.

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [TriToy] [ In reply to ]
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maybe you would have had MORE improvement with one legged drills or PCs.....

Maybe. OTOH, I've never tested anyone who was markedly more efficient than I am, so it would appear that I've reached some sort of upper limit.
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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Re: Does cycling efficiency increase over time/with training/maturation? [TriToy] [ In reply to ]
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define 'markedly'
As in, I don't recall ever testing anyone whose VO2 at a given power was lower than mine by a magnitude greater than the error of the measurement (which is +/- ~2%).
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:
maybe you would have had MORE improvement with one legged drills or PCs.....

Maybe. OTOH, I've never tested anyone who was markedly more efficient than I am, so it would appear that I've reached some sort of upper limit.
Is this some magical limit, like the 4 minute, mile perhaps? Just because you have not seen something does not make it impossible nor, necessarily, unlikely.

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:


3. Nope. OTOH, I can tell you that I was >75% type I in my v. lateralis before the first measurements shown, which may explain why my efficiency hasn't improved as much as Armstrong's apparently did (i.e., a "ceiling effect").
Let's assume all your improvements over these many years have come about because of fibre type conversion. If you started at 75% slowtwtich fibre concentration, exactly what would it have to be now to account for an approximate 10% GE improvement that I see in your data.

Another question, at 250 watts, what percentage of your leg muscle fibres must fire each time to generate that force, assuming your technique hasn't changed? IOW, what percentage of your max power is that number?

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [Frank Day] [ In reply to ]
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In Reply To:
Let's assume all your improvements over these many years have come about because of fibre type conversion. If you started at 75% slowtwtich fibre concentration, exactly what would it have to be now to account for an approximate 10% GE improvement that I see in your data.


Well based on the linear regression shown in Fig. 1A of this study:

http://www.ncbi.nlm.nih.gov/...anel.Pubmed_RVDocSum

a 10% (relative, not absolute) improvement in gross efficiency would correspond to about a 20% (absolute, not relative) change in type 1 fiber percentage.

In Reply To:
Another question, at 250 watts, what percentage of your leg muscle fibres must fire each time to generate that force, assuming your technique hasn't changed? IOW, what percentage of your max power is that number?

The % of motor units recruited is actually much more closely related to the percentage of VO2max elicited, not the % of maximal power (or force). IOW, we appear to rely (primarily) on recruitment up to ~100% of VO2max, then rate-coding is called into play thereafter. So, to answer your question: about 65-70%.
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:

The % of motor units recruited is actually much more closely related to the percentage of VO2max elicited, not the % of maximal power (or force). IOW, we appear to rely (primarily) on recruitment up to ~100% of VO2max, then rate-coding is called into play thereafter. So, to answer your question: about 65-70%.
This is interesting. What does rate-coding mean?
From context I'm guessing something to do with fiber type of different motor units?



Erik
Strava
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Re: Does cycling efficiency increase over time/with training/maturation? [mcdoublee] [ In reply to ]
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What does rate-coding mean?

Increasing force output by increasing the frequency with which particular motor units are activated, as opposed to increasing force output by activating more motor units (i.e., "recruitment").
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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Interesting. Is it a bit of evidence to support the fact that guys in "advanced" years can do very well at IM distances? Even though VO2 max and power at VO2 max may start declining past the mid-thirties, there may yet still be small gains to be made in efficiency at sub-maximal power.

My only comment is that six data points seems pretty sparse considering the "100+" tests. And 4 of the points are bunched in one 5-year period. If you throw out the '82 point, then suddenly the curve starts to look rather flat. Even flat, however, seems to be evidence of increased efficiency because you're at least staving off the ravages of aging.

Don't get all the negative posts about this considering you went out of your way to explain this isn't a Nature article.
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:
In Reply To:
Let's assume all your improvements over these many years have come about because of fibre type conversion. If you started at 75% slowtwtich fibre concentration, exactly what would it have to be now to account for an approximate 10% GE improvement that I see in your data.


Well based on the linear regression shown in Fig. 1A of this study:

http://www.ncbi.nlm.nih.gov/...anel.Pubmed_RVDocSum

a 10% (relative, not absolute) improvement in gross efficiency would correspond to about a 20% (absolute, not relative) change in type 1 fiber percentage.

In Reply To:
Another question, at 250 watts, what percentage of your leg muscle fibres must fire each time to generate that force, assuming your technique hasn't changed? IOW, what percentage of your max power is that number?

The % of motor units recruited is actually much more closely related to the percentage of VO2max elicited, not the % of maximal power (or force). IOW, we appear to rely (primarily) on recruitment up to ~100% of VO2max, then rate-coding is called into play thereafter. So, to answer your question: about 65-70%.
So, let me get this straight. To see the improvement in efficiency over the years and have it solely attributable to changes in fibre type you would now have to have approximately 95% Type I fibres. Could you point to a study that suggests how one would train to achieve such a change.

We can agree that power comes from a combination of recruited fibers and the "contractility" of those fibres, what you have chosen to call rate-coding. However, I would presume that VO2 max for a cyclist occurs somewhere near their max power output, which is why I asked the question. Regardless of how I asked the question, if you did this testing at 250 watts, what percentage of your Vo2 max does this represent? and what percentage of your muscle fibers do you think are being recruited to do this job? If it is substantially less than 75% why do you think there were any substantial numbers of type I fibers being utilized during this testing back in the 80's or now, which there would have to be to see any increase in efficiency at this power.

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [trail] [ In reply to ]
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Interesting. Is it a bit of evidence to support the fact that guys in "advanced" years can do very well at IM distances? Even though VO2 max and power at VO2 max may start declining past the mid-thirties, there may yet still be small gains to be made in efficiency at sub-maximal power.

You don't have to even bring aging into it - it has long been hypothesized that the reason that (male) endurance athletes tend to peak in their late 20s/early 30s is because efficiency continues to slowly improve even after VO2max and LT have plateaued.

In Reply To:
My only comment is that six data points seems pretty sparse considering the "100+" tests.

Indeed, it is, but that's simply because I haven't made a habit of measuring my gross efficiency, and and used specific criteria to filter the data to make it as "clean" as possible.

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And 4 of the points are bunched in one 5-year period. If you throw out the '82 point, then suddenly the curve starts to look rather flat.

I agree.

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Even flat, however, seems to be evidence of increased efficiency because you're at least staving off the ravages of aging.

Well, except that you wouldn't expect cycling efficiency to decrease with age.
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Re: Does cycling efficiency increase over time/with training/maturation? [Frank Day] [ In reply to ]
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So, let me get this straight. To see the improvement in efficiency over the years and have it solely attributable to changes in fibre type you would now have to have approximately 95% Type I fibres.

Based on the cross-sectional study from Coyle's lab, anyway.

In Reply To:
Could you point to a study that suggests how one would train to achieve such a change.

Nope.

In Reply To:
We can agree that power comes from a combination of recruited fibers and the "contractility" of those fibres, what you have chosen to call rate-coding.

Uh, no: contractility is something else entirely.

In Reply To:
However, I would presume that VO2 max for a cyclist occurs somewhere near their max power output

That's a really bad presumption (assumption). For example, my max power is >900 W, even though I reach VO2 max at ~350 W.

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if you did this testing at 250 watts, what percentage of your Vo2 max does this represent?

65-70%

In Reply To:
and what percentage of your muscle fibers do you think are being recruited to do this job?

Roughly 65-70% (at least in the v. lateralis).

In Reply To:
If it is substantially less than 75% why do you think there were any substantial numbers of type I fibers being utilized during this testing back in the 80's or now, which there would have to be to see any increase in efficiency at this power.

That's a good question. In return, here's one for you: why are you ranting about fiber type when I never said anything about it in my original post, and have never claimed that a change in fiber type is why my efficiency has apparently improved??
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:

That's a good question. In return, here's one for you: why are you ranting about fiber type when I never said anything about it in my original post, and have never claimed that a change in fiber type is why my efficiency has apparently improved??

Ugh, because this is what you wrote in the original post:
Quote:
I've mentioned several times before that the data I have on myself is consistent with what Coyle reported for Armstrong
And, that was the mechanism Coyle claimed caused this improvement and you have consistently said, in supporting Coyles conclusion, that was the only way such improvement could be had. I wondered if your data would support such a conclusion. I submit it does not nor is it even plausible.

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [Frank Day] [ In reply to ]
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In Reply To:
In Reply To:

That's a good question. In return, here's one for you: why are you ranting about fiber type when I never said anything about it in my original post, and have never claimed that a change in fiber type is why my efficiency has apparently improved??

Ugh, because this is what you wrote in the original post:
Quote:
I've mentioned several times before that the data I have on myself is consistent with what Coyle reported for Armstrong
Data, Frank...data.
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:
In Reply To:
In Reply To:

That's a good question. In return, here's one for you: why are you ranting about fiber type when I never said anything about it in my original post, and have never claimed that a change in fiber type is why my efficiency has apparently improved??

Ugh, because this is what you wrote in the original post:
Quote:
I've mentioned several times before that the data I have on myself is consistent with what Coyle reported for Armstrong
Data, Frank...data.
Coyle reported that the changes were due to muscle efficiency changes from changing fiber types. You are showing an apparent efficiency improvement as Coyle reported. But, your data (since we have some muscle biopsy data) is not consistent Coyles explanation as to how Armstrong's efficiency improved.

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [Frank Day] [ In reply to ]
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In Reply To:
In Reply To:
In Reply To:
In Reply To:

That's a good question. In return, here's one for you: why are you ranting about fiber type when I never said anything about it in my original post, and have never claimed that a change in fiber type is why my efficiency has apparently improved??

Ugh, because this is what you wrote in the original post:
Quote:
I've mentioned several times before that the data I have on myself is consistent with what Coyle reported for Armstrong
Data, Frank...data.
Coyle reported that the changes were due to muscle efficiency changes from changing fiber types. You are showing an apparent efficiency improvement as Coyle reported. But, your data (since we have some muscle biopsy data) is not consistent Coyles explanation as to how Armstrong's efficiency improved.
No, Coyle hypothesized that Armstrong's efficiency improved as a result of a change in fiber type. My data are neither consistent nor inconsistent with this hypothesis, since longitudinal measurements are lacking.
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Re: Does cycling efficiency increase over time/with training/maturation? [Andrew Coggan] [ In reply to ]
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In Reply To:
In Reply To:
In Reply To:
In Reply To:
In Reply To:

That's a good question. In return, here's one for you: why are you ranting about fiber type when I never said anything about it in my original post, and have never claimed that a change in fiber type is why my efficiency has apparently improved??

Ugh, because this is what you wrote in the original post:
Quote:
I've mentioned several times before that the data I have on myself is consistent with what Coyle reported for Armstrong
Data, Frank...data.
Coyle reported that the changes were due to muscle efficiency changes from changing fiber types. You are showing an apparent efficiency improvement as Coyle reported. But, your data (since we have some muscle biopsy data) is not consistent Coyles explanation as to how Armstrong's efficiency improved.
No, Coyle hypothesized that Armstrong's efficiency improved as a result of a change in fiber type. My data are neither consistent nor inconsistent with this hypothesis, since longitudinal measurements are lacking.
Coyle put it in the title of the paper as to what the paper showed. That is a statement from Coyle that makes it more than a hypothesis in my mind. 99.9% of the people who read this paper believe that is what he showed. In his discussion it is the only possible explanation he gave (even though couched as a hypothesis) and you have defended him as stating it is the only plausible explanation. The Armstrong data does not support that explanation and your data does not support that explanation. In fact, your data would tend to refute that explanation as it is most unlikely that you improved the fibre mix in your legs to 95% Type I, what it would take to see the efficiency improvements you saw from that mechanism alone according to you.

--------------
Frank,
An original Ironman and the Inventor of PowerCranks
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Re: Does cycling efficiency increase over time/with training/maturation? [Frank Day] [ In reply to ]
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Coyle put it in the title of the paper as to what the paper showed.

Yeah: and the title says nothing about fiber type (or training, for that matter).

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In his discussion it is the only possible explanation he gave (even though couched as a hypothesis) and you have defended him as stating it is the only plausible explanation.

And IMO (which is far more valued among "The Fraternity" than yours), it is the only really plausible explanation. (Which is not to say that I would have written the paper the same way, or accepted it as it was written.)

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The Armstrong data does not support that explanation and your data does not support that explanation. In fact, your data would tend to refute that explanation as it is most unlikely that you improved the fibre mix in your legs to 95% Type I

To play devil's advocate: why? It's been reported that the percentage of type I fibers increases with age, so why couldn't someone who is 75% type I in their early 20s progress to 95% type I fibers over 20+ years?

Another point to consider: there doesn't have to be a change in histochemically-demonstrable fiber type percentage for there to be a reduction in myosin ATPase activity, and it is the latter that is really the issue here...
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