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Powercranks - Page 6

post #76 of 391

Re: Powercranks

"Andy Coggan" <acoggan@earthlink.net> wrote in message
news:3d9Ub.11660$F23.9804@newsread2.....earthlink.net...
> "Phil Holman" <philjud@earthlink.not> wrote in message
> news:aVVTb.10968$F23.2757@newsread2.....earthlink.net...
>
> > And it just so happens that the limiting factor for cycling occurs
at
> > the point when the quads and glutes are fully developed and engaged
and
> > not one muscle fibre more (tongue in cheek) What a
coincidence.....don't
> > you think?
>
> Never heard of the principle of symmorphosis, eh Phil?
>
One doesn't even need to look that one up. The pertinent question is does engaging more muscle mass
drive improvements in aerobic capacity. Try extracting an overwhelming definitive answer to that
question from the articles in pub med. The other outstanding question is the significance of the
published test showing improvements in GE.

Phil Holman
post #77 of 391

Re: Powercranks

"Andy Coggan" <acoggan@earthlink.net> wrote in message
news:K99Ub.11657$F23.5705@newsread2.....earthlink.net...
> "Andrew Bradley" <andbrad2002@yahoo.co.uk> wrote in message
> news:53029f74.0402040402.471f44fe@posting.google.com...
> > fday@powercranks.com (Frank Day) wrote in message
> news:<69319bd2.0402031433.3875828a@posting.google.com>...
> >
> > >Most significant to my mind was the improvement in pedaling efficiency (watts per VO2
> > >uptake) from
21
> > > to 23% which correlated with a 14 bpm drop in HR at the same power (155 to 141) if I remember
> > > the number correctly. The non PC group showed some improvement but it was insignificant
> > > statistically.
There
> > > was no improvement in VO2 max at the end for either group.
> >
> > If you said "Powercranks are more efficient" I'd say yes, because
you
> > use a lower cadence and lower cadence is more efficient. But here cadence was fixed at 80rpm.
> >
> > Are these the results you expected? I would have thought, if
anything,
> > VO2 max would have come out higher due to the "more muscle groups" thing.
> >
> > Do you have an explanation of what was found here?
> >
> > The study didn't come up with a convincing explanation, especially
not
> > (speaking of training the 9 o'clock to TDC sector):
> >
> > "Training this third phase with powercranks may give a more
effective
> > pedal stroke, reducing or eliminating any negative torque produced (and thus, wasted energy) and
> > allowing more energy to be transfered
to
> > the forward movement of the bicycle."
>
> The study in question also didn't have an appropriate "attention
control"
> group - which may explain why it was published in the journal that it
was.
>

Your lack of commentary on the physiological aspects of this test are very noticeable.

Phil Holman
post #78 of 391

Re: Powercranks

"Andy Coggan" <acoggan@earthlink.net> wrote in message news:<M69Ub.11652$F23.5666@newsread2.news.pas.earthlink.net>...
> "Frank Day" <fday@powercranks.com> wrote in message
> news:69319bd2.0402040704.4e19fd30@posting.google.com...
> > aerobic capacity follows the muscle capacity. sports activities are not limited by the ability
> > of the heart and lungs but by the limiting muscle or muscle groups going anaerobic.
> >
> > It is that simple folks.
>
> Sorry, but it's not that simple. First, skeletal muscle is not anaerobic at any intensity less
> than 100% of VO2max. Second, convective O2 delivery (determined by cardiac output and arterial O2
> content) does indeed limit aerobic capacity (i.e., VO2max).
>
> Andy Coggan

What have you been smokin'? Isometric contraction can take any muscle anaerobic without any change
in cardiac output because blood flow stops to any muscle if the intramuscular pressure is greater
than arterial pressure. If we were to put you in a hand cycle I can assure you your arms would go
anaerobic well before you reached your VO2 max.

And what is this "convective O2 delivery" you are talking about? All O2 delivery is by diffusion and
the rate is determined by the diffusion gradiant. It diffuses across the lung, is passively
transported to the tissues by the arteries, where it is transported to the cells from the
capillaries again by diffusion and where CO2 is picked up for passive transport back to the lungs
where is diffuses across into the alveoli for exhalation. As long as the hemoglobin concentration is
normal, the diffusion gradiant in the muscle is the limiting factor, not the ability of the heart to
deliver blood to the tissue. You could artificially double the delivery of blood to the tissue and
not increase the delivery of oxygen to the tissue. Oxygen delivery is not limited by cardiac output
limitations.

You are blowing smoke. What is your evidence for such hogwash? Give me a reference in a standard
medical text please.
post #79 of 391

Re: Powercranks

"Phil Holman" <philjud@earthlink.not> wrote in message
news:RMgUb.12190$F23.11149@newsread2....earthlink.net...
>
> "Andy Coggan" <acoggan@earthlink.net> wrote in message
> news:3d9Ub.11660$F23.9804@newsread2.....earthlink.net...
> > "Phil Holman" <philjud@earthlink.not> wrote in message
> > news:aVVTb.10968$F23.2757@newsread2.....earthlink.net...
> >
> > > And it just so happens that the limiting factor for cycling occurs
> at
> > > the point when the quads and glutes are fully developed and engaged
> and
> > > not one muscle fibre more (tongue in cheek) What a
> coincidence.....don't
> > > you think?
> >
> > Never heard of the principle of symmorphosis, eh Phil?
> >
> One doesn't even need to look that one up.

Why not? Knowledge of the concept - even the mere fact that it exists - reveals the fallacy of
your argument.

Andy Coggan
post #80 of 391

Re: Powercranks

"Andy Coggan" <acoggan@earthlink.net> wrote in message
news:aliUb.12324$F23.3936@newsread2.....earthlink.net...
> "Phil Holman" <philjud@earthlink.not> wrote in message
> news:RMgUb.12190$F23.11149@newsread2....earthlink.net...
> >
> > "Andy Coggan" <acoggan@earthlink.net> wrote in message
> > news:3d9Ub.11660$F23.9804@newsread2.....earthlink.net...
> > > "Phil Holman" <philjud@earthlink.not> wrote in message
> > > news:aVVTb.10968$F23.2757@newsread2.....earthlink.net...
> > >
> > > > And it just so happens that the limiting factor for cycling
occurs
> > at
> > > > the point when the quads and glutes are fully developed and
engaged
> > and
> > > > not one muscle fibre more (tongue in cheek) What a
> > coincidence.....don't
> > > > you think?
> > >
> > > Never heard of the principle of symmorphosis, eh Phil?
> > >
> > One doesn't even need to look that one up.
>
> Why not? Knowledge of the concept - even the mere fact that it
exists -
> reveals the fallacy of your argument.
>
If it were that simple why the apparent excess of lung capacity?

Phil Holman
post #81 of 391

Re: Powercranks

"Frank Day" <fday@powercranks.com> wrote in message
news:69319bd2.0402041540.7b890a6c@posting.google.com...
> "Andy Coggan" <acoggan@earthlink.net> wrote in message news:
> > The study in question also didn't have an appropriate "attention
control"
> > group - which may explain why it was published in the journal that it
was.
> >
> > Andy Coggan
>
> I have read a lot of studies and never heard of an "attention control" group. Now you can teach me
> what it is and why this might explain why it was published in the journal it was, beyond it didn't
> meet your high standards.
>
> How would you have designed this study?

An "attention control" group receives the same additional attention that an experimental group
receives, but in a different form. The purpose of such a group is to help determine whether any
treatment effect observed is really due to the treatment, or is some unspecific response resulting
simply from taking part in experimental study.

Andy Coggan
post #82 of 391

Re: Powercranks

"Phil Holman" <philjud@earthlink.not> wrote in message
news:JbhUb.12223$F23.6821@newsread2.....earthlink.net...
>
> "Andy Coggan" <acoggan@earthlink.net> wrote in message
> news:K99Ub.11657$F23.5705@newsread2.....earthlink.net...
> > "Andrew Bradley" <andbrad2002@yahoo.co.uk> wrote in message
> > news:53029f74.0402040402.471f44fe@posting.google.com...
> > > fday@powercranks.com (Frank Day) wrote in message
> > news:<69319bd2.0402031433.3875828a@posting.google.com>...
> > >
> > > >Most significant to my mind was the improvement in pedaling efficiency (watts per VO2 uptake)
> > > >from
> 21
> > > > to 23% which correlated with a 14 bpm drop in HR at the same power (155 to 141) if I
> > > > remember the number correctly. The non PC group showed some improvement but it was
> > > > insignificant statistically.
> There
> > > > was no improvement in VO2 max at the end for either group.
> > >
> > > If you said "Powercranks are more efficient" I'd say yes, because
> you
> > > use a lower cadence and lower cadence is more efficient. But here cadence was fixed at 80rpm.
> > >
> > > Are these the results you expected? I would have thought, if
> anything,
> > > VO2 max would have come out higher due to the "more muscle groups" thing.
> > >
> > > Do you have an explanation of what was found here?
> > >
> > > The study didn't come up with a convincing explanation, especially
> not
> > > (speaking of training the 9 o'clock to TDC sector):
> > >
> > > "Training this third phase with powercranks may give a more
> effective
> > > pedal stroke, reducing or eliminating any negative torque produced (and thus, wasted energy)
> > > and allowing more energy to be transfered
> to
> > > the forward movement of the bicycle."
> >
> > The study in question also didn't have an appropriate "attention
> control"
> > group - which may explain why it was published in the journal that it
> was.
> >
>
> Your lack of commentary on the physiological aspects of this test are very noticeable.

You want some commentary? Okay, here it is: I don't believe the results, and I predict that they
cannot be replicated.

Andy Coggan
post #83 of 391

Re: Powercranks

"Andy Coggan" <acoggan@earthlink.net> wrote in message
news:cmiUb.12326$F23.3523@newsread2.....earthlink.net...
> "Phil Holman" <philjud@earthlink.not> wrote in message
> news:JbhUb.12223$F23.6821@newsread2.....earthlink.net...
> >
> > "Andy Coggan" <acoggan@earthlink.net> wrote in message
> > news:K99Ub.11657$F23.5705@newsread2.....earthlink.net...
> > > "Andrew Bradley" <andbrad2002@yahoo.co.uk> wrote in message
> > > news:53029f74.0402040402.471f44fe@posting.google.com...
> > > > fday@powercranks.com (Frank Day) wrote in message
> > > news:<69319bd2.0402031433.3875828a@posting.google.com>...
> > > >
> > > > >Most significant to my mind was the improvement in pedaling efficiency (watts per VO2
> > > > >uptake)
from
> > 21
> > > > > to 23% which correlated with a 14 bpm drop in HR at the same
power
> > > > > (155 to 141) if I remember the number correctly. The non PC
group
> > > > > showed some improvement but it was insignificant
statistically.
> > There
> > > > > was no improvement in VO2 max at the end for either group.
> > > >
> > > > If you said "Powercranks are more efficient" I'd say yes,
because
> > you
> > > > use a lower cadence and lower cadence is more efficient. But
here
> > > > cadence was fixed at 80rpm.
> > > >
> > > > Are these the results you expected? I would have thought, if
> > anything,
> > > > VO2 max would have come out higher due to the "more muscle
groups"
> > > > thing.
> > > >
> > > > Do you have an explanation of what was found here?
> > > >
> > > > The study didn't come up with a convincing explanation,
especially
> > not
> > > > (speaking of training the 9 o'clock to TDC sector):
> > > >
> > > > "Training this third phase with powercranks may give a more
> > effective
> > > > pedal stroke, reducing or eliminating any negative torque
produced
> > > > (and thus, wasted energy) and allowing more energy to be
transfered
> > to
> > > > the forward movement of the bicycle."
> > >
> > > The study in question also didn't have an appropriate "attention
> > control"
> > > group - which may explain why it was published in the journal that
it
> > was.
> > >
> >
> > Your lack of commentary on the physiological aspects of this test
are
> > very noticeable.
>
> You want some commentary? Okay, here it is: I don't believe the
results, and
> I predict that they cannot be replicated.
>
Thanks, in that case I won't waste my time until this point is cleared up. How is your testing of
Rotor Cranks going?

Phil Holman
post #84 of 391

Re: Powercranks

Per Elmsäter wrote:
>
> Another side question when I have both of you in this thread

I think it's important to clarify that Andy is the Real Deal and I'm just slummin' here while I wait
for Het Volk.
post #85 of 391

Re: Powercranks

"Andrew Bradley" <andbrad2002@yahoo.co.uk> wrote in message news:<mpdUb.191$Y%6.29781@wards.force9.net>...
> Frank Day <fday@powercranks.com> wrote in message
> news:69319bd2.0402041042.43c8b552@posting.google.com...
> ><snip> Simply not fighting onself by completely unweighting the recovery leg is enough to account
> >for this gain.
>
> Surely that just just means you pull up instead of pushing down harder, where's the gain? (that's
> why I said i wasn't convinced when they used this argument in the study)

No, because we are humans and not machines so we do not have an unlimited ability to just increase
force. Muscles loose efficiency if they are contracting "too hard" so allowing the muscle to
contract less hard, because it doesn't have to push up the recover foot improves contractile
efficiency so more "work" is done for less energy. Since the pulling up leg is also at a low force
contractile state it will also be more efficient than the one alone. By spreading out the effort
allows one to come up to the higher forces if one needs to which is what allows the power increases.
Something has to explain the HR drop from 155 to 141 at the same power in 6 weeks and it couldn't
possibly be training effect, at least not in my experience. Perhaps it is another mechanism but that
is how I explain it.

>
> >Another explanation is that coordination changes such that forces are better directed along the
> >tangential improving efficiency.
>
> I don't see an obvious link between pedal force angle and efficiency.

The driving force is actually the torque, not the pedal force. The highest torque occurs when the
pedal force is directed at 90 degrees to the crank arm. Anything other than 90 degrees means the
muscle is contracting just as hard but doing less work than possible. It is simple mechanics. If the
negative forces on the recovery portion of the stroke could be eliminated and the forces could all
be converted to become tangential to the circle cycling efficiency could probably be improved close
to 35 - 40%. That is almost a doubling of what most people are doing now.

>
> An outside possibility is that there is less negative muscle work on the upstroke than on the
> downstroke. (There will likely be a bit of negative muscle work on the downstroke via one or both
> calf muscles being forcibly lengthened, perhaps a bit of antagonistic hamstring work.)

With Powercranks, it is impossible to apply negative force on the upstroke but the tests were done
on regular cranks so it might have occurred, In fact, it probably did, just less intense.

>
> But even assuming a perfectly efficient upstroke, we can't tell whether this kind of effect could
> account for the results since we don't actually know how powerful the upstrokes were. (It would
> have been nice to see pedal forces measured).

You are right. Additional study is required to be able to determine exactly the mechanism of the
efficiency improvement. My mechanisms are conjecture I admit.
post #86 of 391

Re: Powercranks

dvt wrote:
>>
>> Here's the pointer to the abstract that Phil posted earlier: http://tinyurl.com/2nthp
>>
>> Read it again. It's a 2% improvement in efficiency, not in power.
>
> That means the rider can produce the same power with 11.6% less energy in the "after" case. That
> would be noticeable.

1. It may sound big but it may not necessarily be noticeable. How much do you eat during a 40K TT?
Multiply that by 1.11.
2. It may sound big and it's enormous, especially for six weeks of training (3X per week, 1 hour per
workout). Depending on how suspicious your nature is, this is part of the reason why some critics
have wondered whether the experiment was properly controlled.
3. Efficiency is an odd thing to have hung one's a priori hypothesis on. The allure and promise of
PowerCranks is that they make you faster, not that they let you eat less. Let's say you have a
race car and a guy says if you make this change in the engine you'll get more power. You make the
change and rather than test the change in horsepower, you set up the test with the a priori
hypothesis that gas mileage will improve. Hmmm. Anyway, the test shows that the gas mileage *has*
improved. Is this supporting evidence that you'll get more power from that engine?
post #87 of 391

Re: Powercranks

"Robert Chung" <invalid@nospam.com> wrote in message
news:4021d9a5$0$11214$626a54ce@news.free.fr...
> dvt wrote:
> >>
> >> Here's the pointer to the abstract that Phil posted earlier: http://tinyurl.com/2nthp
> >>
> >> Read it again. It's a 2% improvement in efficiency, not in power.
> >
> > That means the rider can produce the same power with 11.6% less energy in the "after" case. That
> > would be noticeable.
>
> 1. It may sound big but it may not necessarily be noticeable. How much
do
> you eat during a 40K TT? Multiply that by 1.11.
> 2. It may sound big and it's enormous, especially for six weeks of training (3X per week, 1 hour
> per workout). Depending on how
suspicious
> your nature is, this is part of the reason why some critics have
wondered
> whether the experiment was properly controlled.
> 3. Efficiency is an odd thing to have hung one's a priori hypothesis
on.
> The allure and promise of PowerCranks is that they make you faster,
not
> that they let you eat less. Let's say you have a race car and a guy
says
> if you make this change in the engine you'll get more power. You make
the
> change and rather than test the change in horsepower, you set up the
test
> with the a priori hypothesis that gas mileage will improve. Hmmm.
Anyway,
> the test shows that the gas mileage *has* improved. Is this supporting evidence that you'll get
> more power from that engine?

I tend to look at it this way. If I produce 1000watts of power with a 22% efficiency then 220 watts
will propel me forward. If my efficiency increases to 25% then my useful power output will increase
to 250 watts.

Phil Holman
post #88 of 391

Re: Powercranks

In article <69319bd2.0402050753.752de5aa@posting.google.com>,
Frank Day <fday@powercranks.com> wrote:
> I didn't see that the PC group reeceived any additional attention.

They had a crank that they would recognise as new and interesting. The control group had normal
cranks. Anyone who's tried to verify if new software is more productive than the older stuff will
know this problem: the people who have the new stuff feel more loved. It's hard to control for.

ian
post #89 of 391

Re: Powercranks

Terry Morse <tmorse@spamcop.net> wrote in message news:<tmorse-29E75C.16103004022004@news.covad.net>...
> You're bringing up a completely different argument, then trying to refute it. Let's stick to the
> subject. The heart's blood carrying capacity does indeed have an impact on the lactate threshold.
> When the heart can carry more blood to the liver and kidneys during exercise, the clearing of
> lactate is increased, and the lactate threshold is increased.
>
> Given your invention, I can understand why you fixate on muscle development as the only tool to
> improve performance. This fixation leads to oversimplification, as evidenced above. The human body
> is a system, with tightly coupled components.

No I am not. In a prior life I was trained as an anesthesiolgist. I understand cardiopulmonary
physiology and delivery of oxygen to the tissues. I realize the body has tightly coupled components.
That is the job of an anesthesiologist, to understand these couplings and manage them as best as
possible under the most severe conditions (simple exercise pales in comparison to some of them).

Oxygen does no good until it gets to the mitochondria. One must look at all of the steps involved in
getting oxygen from the atmosphere to the mitochondria to understand the limiter. By the same
notion, lactate is also produced in the mitochondria and one must look at all of its effects and how
the body handles it before one can understand its effects on performance. Mentioning the liver
ignores how the lactate gets from the mitochondria to the liver and what happens in between.
Further, blood flow to the liver is passive and pretty much constant under normal conditions and has
no effect on lactate threshold although, how fast it metabolizes lactate (enzyme system) does
determine how much production can be tolerated long term and the rate of recovery from severe
anaerobic efforts.

It is not possible to explain all of these nuances to most of you because you don't have the medical
background to understand them.

Frank
post #90 of 391

Re: Powercranks

Terry Morse <tmorse@spamcop.net> wrote in message news:<tmorse-FB9F9E.22375804022004@news.covad.net>...
> Frank Day wrote:
>
> > > Andy Coggan
> >
> > What have you been smokin'?
>
> Um, Frank,
>
> You are so out of your league:
>
> http://tinyurl.com/2rajq

I don't think so. At least as regards the the issues being discussed here. When he puts forth some
science to refute my statements other than "I pronounce me right and you wrong" "arguments" then I
will listen. A big resume may convince some that pronouncements are based on science and not bias
but not me when I have independent substantial knowledge of the subject under discussion.

Evidence of AC's bias can be found in a later post in this thread: "You want some commentary? Okay,
here it is: I don't believe the results, and I predict that they cannot be replicated."

As an academic he should be embarassed to write that. I predict he won't be.

Frank
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