Data (was PowerCranks Study)

"Phil Holman" wrote in message
nk.net...

"Jim Martin" wrote in message
...
Interesting that they finally got this study published. What journal
accepted it? When they presented the abstract at ACSM people lined up
at the
mic to bash the study. The moderator finally had to cut it off.

Any of them named Racer X by chance.

If memory serves those at the mic included Jeff Broker (then the head of
biomechanics at USOC), Dave Martin (Austalian Inst of Sport), a few others,
and me.

It hasn't been published yet

Yes, but what journal WILL it apear in?

Cheers,

Jim



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"Phil Holman" wrote in message
m...
"Robert Chung" wrote in message
...
Phil Holman wrote:

Significant is the 2% increase in Gross Efficiency of the PC group.

1. Anything about delta efficiency?
2. Any other significant differences between groups?

If you send me your real email I'll send you a copy. Per Jim Martin's
comment, this has not been published yet and according to the source
of the data, this was scheduled to happen in November. According to
Jim, it might be a challenge.

Phil Holman

Will you send a copy to me please? This hotmail address is good for 1 MB. If
it is larger, please let me know and I will give you another address.

Thanks

"Frank Day" wrote in message
om...
Was the criticism of the original study you heard similar to the
criticisms heard about "cold fusion" (impossible) or related to the
methods and design of the study?

If I recall correctly there were a three major concerns.

1) The study was not hypothesis driven. That is to say, the authors had no
reason, based on existing scientific literature, to hypothesize that
training with the power cranks would change efficiency. Cyclists may wish to
think that pedaling biomechanics will be improved and that the change in
biomechanics will improve efficiency. That is wishful thinking. No one has
ever reported a link between pedaling technique and efficiency. Indeed,
there is little to improve because almost no one produces substantial
negative power during the flexion phase at pedaling rates of under 100rpm.

2) If they had tried to express a hypothesis it could only be centered on a
notion that pulling up is inherently more metabolically efficient than
pushing down: that muscle that flex the leg are more efficient than those
that extend the leg. No one has ever reported such a difference and there is
no reason to hypothesize one.

3) The procedures for calibrating the metabolic system were not well
explained.

In my opinion the most reasonable explanation for their findings is that
something happened to their metabolic system between pre and post testing.

Cheers,

Jim


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Journal of Sports and Conditioning Research.

"Jim Martin" wrote in message Yes, but what journal WILL it apear in?

Cheers,

Jim

I am truly amazed. Rotor cranks does have some pros using them.
However, not to be a name dropper but has anybody looked at some of
the names of pros using PC's. Probably becaause PC's have paid them a
lot of money to do so - NOT! Or, they have been taken in by the hype?
Or, perhaps they see them as actually doing something useful? Perhaps
one of those two, but you will have to ask them.

Wonder why I keep getting emails from Belgium pros saying J. Musseuw
is telling them they need to get on PC's? Not easy for me to hypnotize
someone who doesn't speak much (if any) english.

Are they as good as Rotor Cranks. That really isn't the question,
becaause these two products do different things. The question is: Are
they as good as they claim? And, if not, how good are they? Or, are
they not worth anything?

This study, I think, goes some towards answering those questions.

Frank


(RK) wrote in message
Biopace still has its advocates. The question is: are they as good as
rotor Cranks? They are being used by some 2nd division pros, Spanish
triathletes, et al. They look to be an eccentric cam device intended
to eliminate the dead spot that Power Cranks emphasize for training.

http://www.rotorbike.com/eng/home.htm

RACER X wrote in message ...
Dude,

I already wrote the only review that matters. Why try to reinvent the wheel?

Racer X

Because, Dude, chowderhead's like you try to make us all think you now
**** from Shinola, but really you just don't want the more learned to
make their own judgements for fear they'll call you on your idiocy.

Now, if memory serves me, I believe a friend of mine reviewed this
paper, or a related one, about a year and a 1/2 ago. Perhaps I can
dig it up.

BTW: You wouldn't be related to Awesomebikedude?

"chris" wrote in message
om...
Any chance we can get the full citation? I'd like to review the full
paper.

Chris

Chris, I've tried to email it to you but it comes back ....
This is an automatically generated Delivery Status Notification.

Delivery to the following recipients failed.





Phil Holman

Why don't you just wait until you can read the study then criticize
what was finally published. I think you will find most of the concerns
you addressed adequately covered, except for, of course, the bias that
there really can't be any improvement over current pedaling technique
("because almost no one produces substantial negative power during the
flexion phase at pedaling rates under 100 rpm") so any demonstrated
improvement must come from measurement error and I don't believe they
reproduced the technical manuals for the equipment they used
regarding specific calibration procedures beyond commenting on
calibration protocol. Although I am sure the authors could provide
that to you if that criticism remains after you read the article.

Frank

"Jim Martin" wrote in message ...
If I recall correctly there were a three major concerns.

1) The study was not hypothesis driven. That is to say, the authors had no
reason, based on existing scientific literature, to hypothesize that
training with the power cranks would change efficiency. Cyclists may wish to
think that pedaling biomechanics will be improved and that the change in
biomechanics will improve efficiency. That is wishful thinking. No one has
ever reported a link between pedaling technique and efficiency. Indeed,
there is little to improve because almost no one produces substantial
negative power during the flexion phase at pedaling rates of under 100rpm.

2) If they had tried to express a hypothesis it could only be centered on a
notion that pulling up is inherently more metabolically efficient than
pushing down: that muscle that flex the leg are more efficient than those
that extend the leg. No one has ever reported such a difference and there is
no reason to hypothesize one.

3) The procedures for calibrating the metabolic system were not well
explained.

In my opinion the most reasonable explanation for their findings is that
something happened to their metabolic system between pre and post testing.

Cheers,

Jim


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Jim,

Surely you are not saying that there is no evidence in the existing
scientific literature that cycling efficiency is not important or
cannot be changed. I think the literature supports that there is a
wide range of cycling efficiency documented in cyclists varying
usually from about 16% to 23% and, rarely, higher. I think it also
shows that better cyclists typically (but not always) have higher
efficiencies than less expert cyclists. Is there any evidence that
cycling efficiency cannot be changed (improved)? I think it is
generally accepted that improving efficiency is a laudable goal - I
have never heard anyone advocate reducing efficiency.

If there is a product that claims to increase cycling efficiency, one
does not have to have a mechanism by which it works (and, in fact, can
believe there is none and the claims are bogus), in order to study the
product and the claims, in order to debunk them. In choosing to do the
study the researcher can choose either the hypothesis that the device
works or the hypothesis that it doesn't. The data is then analyzed
with respect to the hypothesis. Based upon the statistical
significance of the data (assuming a good study design and no bias is
introduced into the study) the hypothesis is either "proven" or
"disproven" to most people.

Unfortunately for the debunkers, if the claims are substantiated by
the study, then one should not claim the study is bogus simply because
the researchers didn't propose a mechanism beforehand. Rather, the
question should be either: (for the non-believers) Can the study be
improved and is the study repeatable? or (for the believers) What is
the mechanism?

Frank

"Jim Martin" wrote in message ...
1) The study was not hypothesis driven. That is to say, the authors had no
reason, based on existing scientific literature, to hypothesize that
training with the power cranks would change efficiency. Cyclists may wish to
think that pedaling biomechanics will be improved and that the change in
biomechanics will improve efficiency. That is wishful thinking. No one has
ever reported a link between pedaling technique and efficiency. Indeed,
there is little to improve because almost no one produces substantial
negative power during the flexion phase at pedaling rates of under 100rpm.

"Jim Martin" wrote in message
...

"Frank Day" wrote in message
om...
Why don't you just wait until you can read the study then criticize
what was finally published.

I only wrote what I did because, two lines above in this thread, you
asked
me about the criticisms. (See: Was the criticism of the original study
you
heard similar to the
criticisms heard about "cold fusion" (impossible) or related to the
methods
and design of the study?)

Did you not want an answer till later?

I think Frank is justified in his response due to your first message
into this thread. I appreciate the insight you have provided and hope
you continue the discussion both now and later.

Phil Holman