Powercranks

[Phil Holman]

"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> "Frank Day" <[email protected]> wrote in message
> news:[email protected]...
> > "Andy Coggan" <[email protected]> wrote in message
> news:<[email protected]>...
> > > "Frank Day" <[email protected]> wrote in message
> > > news:[email protected]...
> > > > "Andy Coggan" <[email protected]> wrote in message
> > > news:<[email protected]>...
> > > > > "Frank Day" <[email protected]> wrote in message
> > > > > news:[email protected]...
> > > > > > "Andy Coggan" <[email protected]> wrote in message
> > > news:<[email protected]>...
> > > > > > > "Frank Day" <[email protected]> wrote in message
> > > > > > > news:[email protected]...
> > > > > > > > have you ever seen someone unweight completely on the back stroke?
> > > > > > >
> > > > > > > Plenty of examples of this in the scientific literature.
> > > > > >
> > > > > > Not of sustained unweighting I suspect.
> > > > >
> > > > > "You suspect"? Geez...here you are pushing your invention on
the
> world,
> > > and
> > > > > you don't even seem to be aware of what has or hasn't already
been
> done!
> > > > >
> > > > > You want an example of "sustained unweighting"? Okay, go back
and
> look
> > > at
> > > > > the 1991 Coyle paper...almost half of the subjects in that
study
> > > > > demonstrated exactly that during 25 min of continuous
exercise.
> > > >
> > > > "almost half" were able to sustain unweighting (it is not clear
that
> > > > they were completely unweighted or just close but I haven't seen
the
> > > > paper)
> > >
> > > One of many, apparently.
> >
> > apparently! so did they completely unweight for 25 minutes or come close?
>
> Data were actually recorded only during the last min of each 5 min
stage,
> but since the subjects didn't know it was happening then presumably
yes,
> they did completely unweight for 25 min.
>
> > > > for all of 25 minutes. WOW!!! And the average race lasts how long?
> > >
> > > The test was only 25 min long, so it can't be said how long these
> athletes
> > > could have maintained that force application pattern. OTOH, they
weren't
> > > really aware that their force application pattern was being
measured, so
> > > presumably the data reflect their normal pedaling "style".
> >
> > So, did they completely unweight for that period or just come close?
>
> Depends on the subject - as I said, approximately half never showed
any
> negative torque *at all*.
>
> > If they completely unweighted, did they apply any positive force on the complete backstroke or
> > did they just manage to get to zero and hold it?
>
> Again, depends on the subject (as well as where in the upstroke they
were).
> Most were only slightly positive, but at least one subject obtained
~10% of
> their power by pulling up.
>
> > > >Even if that were so, it is not my experience in watching people get on my demonstration
> > > >bikes. About 1% of the people can pedal without falling out of synch for more than a minute.
> > >
> > > Falling out of synch doesn't necessarily mean that somebody isn't unweighting the rising
> > > pedal.
> >
> > It doesn't? What does it mean? All the PowerCrankers out there who
are
> > following this (any who happen to have not fallen asleep) are
anxious
> > to know.
>
> Falling out of synch would, by itself, simply mean that the two legs
are
> traveling at different speeds. I can certainly see how that would
usually be
> associated with fatigue/brief lack of positive torque on the upstroke,
but
> by itself doesn't prove it.

Different speeds means the upward moving leg has decelerated. How does a decelerating leg provide
positive drive to a chainring/BB at constant speed?

>
> > > > You just can't believe that it is possible for an elite to
improve
> > > > that much or to improve without improving VO2 max (which
according to
> > > > you can't really be improved)
> > >
> > > On the contrary, I'm constantly trying to dispel the mistaken
notion
> that
> > > VO2max is genetically fixed and can't be improved by training. My
point
> is
> > > that crippling somebody's ability to pedal a bike in a normal
fashion by
> > > using your cranks isn't going to increase VO2max, either acutely
or over
> a
> > > prolonged period of time.
> >
> > And you are basing that opinion on ...?
>
> The fact that muscle mass isn't limiting to VO2max, as well as the
fact that
> VO2max in elite endurance athletes is comparable across sports that
widely
> differ in the amount of muscle mass recruited.
>
> > > > so you shut your eyes to the data. Museeuw gets on them and 3 weeks later his agent is back
> > > > asking
for
> > > > cranks for his training partners. Hincapie gets on them and in
about
> > > > two weeks I start getting phone calls from people, "George says
I need
> > > > to get on these". I get a call from Telecom awhile back telling
me not
> > > > to use C. Evans as a user in my web advertising as he is under contract. I contact Mr. Evans
> > > > somewhat concerned that I don't
want to
> > > > get him in trouble and he says he will talk to them when the
team gets
> > > > together. I haven't heard anything more from him or them. I give
a 60
> > > > day moneyback guarantee and the return rate is about 5 in a
thousand.
> > > > Even PT Barnum wouldn't claim there are that many suckers out
there.
> > >
> > > Sure there are...and the pro cyclists whose names you drop seem to
be
> among
> > > them.
> >
> > Really?
>
> Yup - suckers. Or I guess you could just say that desperate times
calls for
> desperate measures.
>
> BTW, when *is* Hincapie finally going to win something really big,
anyway?
>
> > > > You are the "man of science" who has the blinders on, as far as
I am
> > > > concerned. The data is the data.
> > >
> > > And what data *are* (not is) those? So far there's one study
claiming
> large
> > > increase in efficiency as a result of training using Powercranks,
but
> that's
> > > it. Moreover, contrary to your claims no new world records have
been set
> by
> > > Powercrank users, and no unknowns/lesser lights have suddenly set
the
> world
> > > on fire as a result of their use.
> >
> > Wrong, I have listed a couple of new WR's on another post.
>
> Which, as others have pointed out, can readily be explained by
advances in
> aerodynamic design, not any increase in human power output.

The same applies to Boardman's aero assisted hour record. IOW, there is no proof or information that
you would accept.

>
> >Of course, they probably aren't the kinds of records you think are important so it will be easy
> >to discount them, I suspect.
>
> On the contrary, I think "speedbikes" (as Mark Weaver likes to call
them)
> are one of the coolest things going, and I'd jump at the chance to be involved in any such effort.
> However, it is precisly because of the
crucial
> importance of technology in this arena that I discount the records you
cite
> as proof that Powercranks work.
>
> >And the fact there is only one study. Well, there has to be a first. We will see what subsequent
> >studies show. Perhaps you are right. Maybe this is cold fusion.
>
> I think the snake oil analogy is more apt. At least the folks claiming
to
> have accomplished cold fusion weren't trying to make a fast buck on
their
> bogus claims

I don't think anyone who strives for scientific evidence can be put in the same category.

Phil Holman

 

[Frank Day]

"Andy Coggan" <[email protected]> wrote in message news:<[email protected]>...
> "Frank Day" <[email protected]> wrote in message
> news:[email protected]...
>
> > the abilty to exercise is not limited by the heart or lungs but, rather, by the ability of the
> > muscles being exercised to extract oxygen from the blood. It is the muscles in the legs and arms
> > that go anaerobic (ischemia) and not the heart,
>
> And the reason, ultimately*, that the muscles fail is because the heart can't provide them with
> enough O2-carrying blood. This is proven by the fact that per mass of active tissue, both blood
> flow and O2 uptake are much higher during small muscle mass (e.g., one leg kicking) vs. large
> muscle mass exercise.

It is true that the heart can't provide the tissues with enough O2 carrying blood, but this isn't
because the heart can't deliver more blood, but because there isn't enough capillary density to
deliver the blood flow required by the tissue. The heart can only deliver as much as the capillaries
in the tissue will allow. If you train harder you can develop more capillaries and more blood flow
can ensue and performance will increase. The heart adapts to this increased load. This is called
training effect.

>
> *Of course, mitochondrial respiratory capacity and hence substrate metabolism play a huge role in
> determining what fraction of the muscle's aerobic power output can be maintained for how
> long...but since the heart can't supply all the muscles in the body with all the blood flow and O2
> that they could consume, it is still ultimately the heart that sets the ceiling on sustainable
> exercise intensity.

We don't know how much the heart can supply. In the case of pathologic peripheral shunts or other
pathologicaal condtions cardiac output can be much greater than ever seen during exercise. The heart
seems capable of adapting to all sorts of conditions. VO2 max varies greatly amongst the various
sports and athletes, although when "appropriately corrected" for muscle mass, is reasaonably
constant. The real problem limiting exercise is not muscle capillary density but the fact that it is
not possible to pack much more in the muscle than we do now, at least in the elite athlete. In the
elite athlete, it is not possible to continue to increase the number of contractile elements,
mitochondria, and capillaries in a limited volume all at the same time. If we try to increase
capillary density we may do so at the expense of contractile elements. If we increase contractile
elements (lifting weights) we may do so at the expense of mitochondria or capillary density. It is
this need to balance all of these elements (all of which are necessary to exercise performance)
which really limits our capabilities, not the heart. The RAAM rider probably has a much greater
capillary density and mitochondrial density than most because he needs a much greater aerobic
capability than most, so he sacrifices strength for aerobic endurance. It is all a balancing act. It
appears that AC and i will always disagree on this point, most likely because of my weak background
in this area could never bring my understanding up to his level and I am an obstinent sort. However,
in healthy individuals, I see no evidence that the heart is the limiting factor in athletic
performance ever.
>
> Andy Coggan

 

[Frank Day]

"Andy Coggan" <[email protected]> wrote in message news:<[email protected]>...
> "Frank Day" <[email protected]> wrote in message
> news:[email protected]...
> > Even if pedal speed were allowed to vary and internal resistance were zero, this would not
> > become a peretual motion machine because it requires external energy to keep it going.
>
> Wrong. Wrong, wrong, wrong, wrong, and wrong.

Show me the calculations of how it is possible to vary the pedaling speed to keep the energy of the
rider is constant when pedaling. Isn't a constant energy without input or loss both a necessary and
sufficient condition for a perpetual motion machine? Pronouncements are not sufficient.

 

[N Crowley]

dvt <[email protected]> wrote in message news:<[email protected]>...
> n crowley wrote:
> > T McNamara states that Anquetil attributed his success to tangential force and even discussed
> > it. This confirms what I have known for some time; physiologists, engineers and biomechanical
> > researchers may be experts in their own departments but on the subject of Anquetil's pedaling
> > they appear to have been brain dead for over half a century.
>
> That's a pretty big logical leap, noel. Can you fill in some of the gaps? Beginning with: Anquetil
> discussed the tangential force. Ending with: researchers "have been brain dead for over half a
> century."
>
> > It is interesting to note that while circular pedaling uses direct downward pressure to apply
> > maximum tangential force, Anquetil never came within 40 degrees of using direct downward
> > pressure.
>
> This is the closest I've seen you come to a coherent statement of your thesis. It's still not very
> coherent, but you might be getting closer. You ready to spill the beans? Or are you keeping it a
> secret so you can use it for some personal monetary benefit?
>
> > As Anquetil's special technique can
> > completely eliminate the dead spot area...
>
> See, that's a typical strong statement from you. Where's the backup?
>
> Dave dvt at psu dot edu


Brain dead or lack of innovative spirit with regard to pedaling technique, what's the difference. It
is much easier to attribute a rider's success to drugs that set about trying to discover if it could
be legally done by improved pedaling technique. When a rider believes that all pedaling is like
running up a hill and nothing is going to change that, need any more be said on that subject. As for
the elimination of the dead spot area, it was done by his ankling technique. Like everything else
about Anquetil, it was very different to any other ankling style and had many objectives. By using
the maximum range of ankle movement he could use the same direction for all power application to the
pedal and extend his main (continuous maximum tangential force application) pedal stroke to include
the TDC area (11 to 1 o'clock) while using the same muscle power generation technique throughout the
entire 11 to 5 o'clock area. All of this was necessary for the successful combination and
synchronization of arm resistance which was a vital part of his technique. The position of foot
(from ankle downwards) on pedal never changed, it was in the upper and lower leg that all the
changing of angles occurred. How will Pantani (R.I.P.) be remembered in 50 years time, will his name
automatically appear every time the subject of performance enhancing drugs is being discussed?

 

[Andy Coggan]

"Frank Day" <[email protected]> wrote in message
news:[email protected]...
> "Andy Coggan" <[email protected]> wrote in message news:
> > > Engaging a motor unit is not a guarantee of purfusion.
> >
> > It is if cardiac output is still below its maximum.
>
> No it is not, not if all the precapillary sphincters (that control blood flow to the local tissue)
> are open. Once that occurs the only way to increase blood flow to the muscle is to increase blood
> pressure.
> >
> > > If what you said was true then Olympic Kayakers would have the same VO2 max as Olympic Oarsman
> > > as Olympic cyclists, etc. It just isn't true. VO2 max is limited by the exercised muscle mass
> > > and not the cardiovascular system.
> >
> > Apparently you don't know the differences between VO2max and VO2peak. I suggest that you go read
> > Loring Rowell's now-classic review article to
learn
> > the difference.
>
> Guess I don't. Sorry I don't have it available. I did a google search and was only able to find
> books written on the subject.

Ever heard of a library, Frank? Surely there's one somewhere near you that carries medical journals.

> I will try to get a copy and read it but it ain't going to happen during this thread. Perhaps you
> could enlighten me (and the rest of the list) as to this difference.

It's simple:

1) VO2max = the highest attainable rate of O2 uptake, limited by maximal cardiac output/convective
O2 delivery.

2) VO2peak = anything less than true VO2max, even if it is the highest that that person can achieve
given the exercise modality. Limited by the inability to recruit (actually, sufficiently
vasodilate) enough muscle to drive cardiac output all the way to maximum.

Since trained cyclists can achieve a true VO2max while cycling, all of your claims with regards to
muscle mass are moot, at least when talking about sustainable power output (the energy for which
must be derived aerobically).

Andy Coggan

 

[Andy Coggan]

"Frank Day" <[email protected]> wrote in message
news:[email protected]...
> "Andy Coggan" <[email protected]> wrote in message
news:<[email protected]>...
> > "Frank Day" <[email protected]> wrote in message
> > news:[email protected]...
> >
> > > the abilty to exercise is not limited by the heart or lungs but, rather, by the ability of the
> > > muscles being exercised to extract oxygen from the blood. It is the muscles in the legs and
> > > arms that go anaerobic (ischemia) and not the heart,
> >
> > And the reason, ultimately*, that the muscles fail is because the heart can't provide them with
> > enough O2-carrying blood. This is proven by the
fact
> > that per mass of active tissue, both blood flow and O2 uptake are much higher during small
> > muscle mass (e.g., one leg kicking) vs. large muscle mass exercise.
>
> It is true that the heart can't provide the tissues with enough O2 carrying blood, but this isn't
> because the heart can't deliver more blood, but because there isn't enough capillary density to
> deliver the blood flow required by the tissue.

******** - as I told you, per unit of active tissue muscle blood flow is as much as three-fold
higher during small muscle mass exercise (e.g., 1 leg kicking) vs. large muscle mass exercise (e.g.,
cycling). This clearly demonstrates that there must be active vasocontriction even in exercising
muscle, a point proven by studies using vasodilating drugs. The reason for this vasoconstriction is
apparently to maintain blood pressure: since cardiac output cannot increase beyond that observed
at/near VO2max, the body can't "allow" a large amount of muscle to fully vasodilate because then
perfusion pressure would fall.

As Loring Rowell put it: the heart's job during exercise is to maintain the highest possible blood
pressure against the smallest possible peripheral resistance.

>The heart can only deliver as much as the capillaries in the tissue will allow. If you train harder
>you can develop more capillaries and more blood flow can ensue and performance will increase. The
>heart adapts to this increased load. This is called training effect.

While capillarization does increase with training, this is but one factor contributing to the
improvements in VO2max/performance. More importantly, changes in capillarization are not required to
achieve increases in VO2max. This is shown, e.g., by the fact that acutely increasing convective O2
deliverly via EPO administration, transfusion, hyperoxia, or even expansion of plasma volume (in an
untrained person) increases VO2max w/o, obviously, any change in capillary density.

> > Andy Coggan

 

[Andy Coggan]

"Frank Day" <[email protected]> wrote in message
news:[email protected]...

> I am sorry I am unfamiliar with the literature that seems to say this is impossible and my
> knowedge of basic physics seems to have disappeared (I do think I had a little bit at one time).

What's that saying? Oh yeah: ignorance has no excuse.

> Oh well, I guess I will just have to remain the laughingstock of the scientific community (at
> least, those in the know).

Don't worry, you will.

Andy Coggan

 

[Andy Coggan]

"Phil Holman" <[email protected]> wrote in message
news:[email protected]...
>
> "Andy Coggan" <[email protected]> wrote in message
> news:[email protected]...
> > "Frank Day" <[email protected]> wrote in message
> > news:[email protected]...
> >
> > > the abilty to exercise is not limited by the heart or lungs but, rather, by the ability of the
> > > muscles being exercised to extract oxygen from the blood. It is the muscles in the legs and
> > > arms that go anaerobic (ischemia) and not the heart,
> >
> > And the reason, ultimately*, that the muscles fail is because the
> heart
> > can't provide them with enough O2-carrying blood. This is proven by
> the fact
> > that per mass of active tissue, both blood flow and O2 uptake are much higher during small
> > muscle mass (e.g., one leg kicking) vs. large
> muscle
> > mass exercise.
> >
> > *Of course, mitochondrial respiratory capacity and hence substrate metabolism play a huge role
> > in determining what fraction of the
> muscle's
> > aerobic power output can be maintained for how long...but since the
> heart
> > can't supply all the muscles in the body with all the blood flow and
> O2 that
> > they could consume, it is still ultimately the heart that sets the
> ceiling
> > on sustainable exercise intensity.
>
> This addresses the upper limit of muscle utilization but what sets the lower limit? At what point
> do we see exercise intensity drop off when we reduce muscle utilization. This question implies
> there is a precise threshold but the complexity of the limitations apparently makes this unclear.
> Your position is that the muscles used in normal pedaling can be trained up to elicit maximum
> capacity and that's it.

That's not my position, that's what direct measurements show.

>There are many articles in pub med which appear to be divided on this issue.

I defy you to point to one original article that contradicts anything I've written in this thread.

Andy Coggan

 

[Andy Coggan]

"Frank Day" <[email protected]> wrote in message
news:[email protected]...
> "Andy Coggan" <[email protected]> wrote in message
news:<[email protected]>...
> > "Frank Day" <[email protected]> wrote in message
> > news:[email protected]...
> > > Even if pedal speed were allowed to vary and internal resistance were zero, this would not
> > > become a peretual motion machine because it requires external energy to keep it going.
> >
> > Wrong. Wrong, wrong, wrong, wrong, and wrong.
>
> Show me the calculations of how it is possible to vary the pedaling speed to keep the energy of
> the rider is constant when pedaling.

Translation, please.

> Isn't a constant energy without input or loss both a necessary and sufficient condition for a
> perpetual motion machine?

Yes, it is.

Andy Coggan

 

[Andy Coggan]

"Tom Sherman" <[email protected]> wrote in message
news:[email protected]...
> Andy Coggan wrote:
>
> > ...
> >>Of course, they probably aren't the kinds of records you think are important so it will be easy
> >>to discount them, I suspect.
> >
> > On the contrary, I think "speedbikes" (as Mark Weaver likes to call
them)
> > are one of the coolest things going, and I'd jump at the chance to be involved in any such
> > effort. However, it is precisly because of the
crucial
> > importance of technology in this arena that I discount the records you
cite
> > as proof that Powercranks work....
>
> Who is Mark Weaver?
>
> Matt Weaver's website: <http://www.speed101.com/>.

My bad - thanks for setting the record straight.

Andy Coggan

 

[Andy Coggan]

"Terry Morse" <[email protected]> wrote in message
news:[email protected]...
> Andy Coggan wrote:
>
> > Terry Morse wrote:
> > > What changes in the body account for the other 50% of VO2max increase?
> >
> > Increased extraction of O2 from arterial blood.
>
> Okay, that extraction as I understand it shows up as a higher arterial-venous O2 difference (the
> "a-vO2 diff" in the literature). But what's the physiological cause for that increase, an increase
> in capillary density, or something else?

An increase in perfused capillary bed volume may contribute to an increase in O2 extraction by
increasing capillary mean transit time, thus allowing for more complete "unloading" of hemoglobin.
However, as it turns out the percentage increase in capillary density tends to parallel quite
closely the percentage increase in VO2max/maximal cardiac output - this suggests that capillary mean
transit time is only maintained, not increased, as a result of training. This in turn implies that
other factors must be operative as well, in particular a reduction in the mean intramuscular pO2
that helps "pull" more O2 from the blood. A lower intramuscular pO2 during maximal exercise after as
compared to before training would be an expected consequence of having many more mitochondria*
acting as O2 "sinks".

*In reality, a more extensive mitochondrial reticulum...and since O2 is much more soluble in lipid
membranes than in aqueous solutions, this detail may be a factor as well.

Andy Coggan

 

[Phil Holman]

"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> "Phil Holman" <[email protected]> wrote in message
>>Your position is that the muscles used in normal pedaling can be trained up to elicit maximum
>>capacity and that's it.
>
> That's not my position, that's what direct measurements show.
>
> >There are many articles in pub med which appear to be divided
>>on this issue.
>
> I defy you to point to one original article that contradicts anything I've written in this thread.

This has already been demonstrated by the WR produced in answer to your statement in spite of your
response which btw would also apply to Boardman's aero assisted WR. IOW, no example of a WR would
satisfy you. However, as far as pub med articles .......

Andy Coggan states "Since trained cyclists can achieve a true VO2max while cycling, all of your
(Frank Day's) claims with regards to muscle mass are moot, at least when talking about sustainable
power output (the energy for which must be derived aerobically)".

1/VersaClimbing elicits higher VO2max than does treadmill running or rowing ergometry.

Brahler CJ, Blank SE

Department of Kinesiology and Leisure Studies, Washington State University, Pullman 99164-1410, USA.

Collegiate varsity oarswomen and coxswain (N = 11) completed maximal aerobic exercise tests on a
treadmill, a rowing ergometer, and a simulated climbing machine. Successful completion of each test
was evidenced by a plateau in oxygen consumption in response to increasing work rates. VO2max (l.min-
1), and minute ventilation (VE, l.min-1) at VO2max were significantly greater (P < 0.05) during
simulated climbing compared to treadmill running and rowing ergometry. Maximal heart rate (beats.min-
1) was significantly greater (P < 0.05) during climbing and running than during rowing. Findings
indicate that progressive, incremental, whole-body climbing exercise elicits significantly greater
VO2max values for collegiate oarswomen and coxswain than does graded treadmill running or
progressive rowing ergometry.end

The way this can apply to trained cyclists is by illustrating how greater VO2max values can be
attained outside of one's own discipline (one that uses more muscle mass than cycling) by using even
more muscle mass thus contradicting your statement that muscle mass is moot.

2/Peak oxygen consumption and ventilatory thresholds on six modes of exercise.

Smith TD, Thomas TR, Londeree BR, Zhang Q, Ziogas G

Department of Health and Exercise Sciences, University of Missouri, Columbia 65211, USA.

In order to compare responses on six modes of exercise for maximal oxygen consumption (VO2peak) and
ventilatory thresholds (VT-1, VT-2), 10 male recreational exercisers (23 +/- 3 yrs) completed
incremental maximal tests on treadmill, stationary skier, shuffle skier, stepper, stationary cycle,
and rower. After extensive habituation, VO2peak, VT-1, and VT-2 were determined during each maximal
bout. A MANOVA followed by ANOVAs, Tukey post hoc tests, and noncentral F tests indicated that the
treadmill elicited a significantly higher peak oxygen consumption than did the other modes, and the
skier and stepper values were higher than the rower. VO2 at VT-1 was higher on the treadmill than
cycle. The treadmill also elicited a higher VO2 at VT-2 than the shuffle skier, cycle, and rower.
However, no differences were observed among modes for VT-1 and VT-2 when expressed as a percentage
of VO2peak. These results suggest that the treadmill elicits a higher aerobic capacity measure than
other modes, but the ventilatory threshold responses (% VO2peak) are similar among modes.end

This again illustrates how a higher aerobic capacity is elicited by more muscle mass i.e.
treadmill running.
3/Laboratoire des Sciences de l'Activite Physique, Universite Laval, Ste-Foy, Quebec, Canada.

The objective of this study was to evaluate the viability of using a single test in which
cardiorespiratory variables are measured, to establish training guidelines in running and/or cycling
training activities. Six triathletes (two females and four males), six runners (two females and four
males) and six males cyclists, all with 5.5 years of serious training and still involved in racing,
were tested on a treadmill and cycle ergometer. Cardiorespiratory variables [e.g., heart rate (HR),
minute ventilation, carbon dioxide output (VCO2)] were calculated relative to fixed percentages of
maximal oxygen uptake (VO2max; from 50 to 100%). The entire group of subjects had significantly (P <
0.05) higher values of VO2max on the treadmill compared with the cycle ergometer [mean (SEM) 4.7
(0.8) and 4.4 (0.9)
l.min-1, respectively], and differences between tests averaged 10.5% for runners, 6.1% for
triathletes and 2.8% for cyclists.end

Again this contradicts your statement that muscle mass is moot. While some trained cyclists may be
able to achieve a true V02max this obviously isn't the case for all athletes and cyclists. This also
illustrates the greater PC potential for triathletes which possibly explains why their use is more
popular in that sport.

Phil Holman

 

[Phil Holman]

"Andy Coggan" <[email protected]> wrote in message news:b89Xb.2642

> As Andrew Bradley has explained to you (and explained to you, and explained to you, and
> explained to
you), NO -
> none, zero, nada, zip - energy is lost simply due to the legs going
'round
> and 'round. Rather, ALL - every little bit - of the energy loss occurs BEFORE the energy is
> transferred to the limb segments in the first
place
> (this loss being due to the viscoelastic elements in muscle).

The weights used on the legs resulted in significant energy increases and is an indication that the
losses due to just the legs going around are not nada.

http://tinyurl.com/24qxc

Phil Holman

 

[Frank Day]

"Andy Coggan" <[email protected]> wrote in message news:<[email protected]>...
> "Frank Day" <[email protected]> wrote in message
> news:[email protected]...
> > "Andy Coggan" <[email protected]> wrote in message news:
> > > > Engaging a motor unit is not a guarantee of purfusion.
> > >
> > > It is if cardiac output is still below its maximum.
> >
> > No it is not, not if all the precapillary sphincters (that control blood flow to the local
> > tissue) are open. Once that occurs the only way to increase blood flow to the muscle is to
> > increase blood pressure.
> > >
> > > > If what you said was true then Olympic Kayakers would have the same VO2 max as Olympic
> > > > Oarsman as Olympic cyclists, etc. It just isn't true. VO2 max is limited by the exercised
> > > > muscle mass and not the cardiovascular system.
> > >
> > > Apparently you don't know the differences between VO2max and VO2peak. I suggest that you go
> > > read Loring Rowell's now-classic review article to
> learn
> > > the difference.
> >
> > Guess I don't. Sorry I don't have it available. I did a google search and was only able to find
> > books written on the subject.
>
> Ever heard of a library, Frank? Surely there's one somewhere near you that carries medical
> journals.
>
> > I will try to get a copy and read it but it ain't going to happen during this thread. Perhaps
> > you could enlighten me (and the rest of the list) as to this difference.
>
> It's simple:
>
> 1) VO2max = the highest attainable rate of O2 uptake, limited by maximal cardiac output/convective
> O2 delivery.
>
> 2) VO2peak = anything less than true VO2max, even if it is the highest that that person can
> achieve given the exercise modality. Limited by the inability to recruit (actually,
> sufficiently vasodilate) enough muscle to drive cardiac output all the way to maximum.
>
> Since trained cyclists can achieve a true VO2max while cycling, all of your claims with regards to
> muscle mass are moot, at least when talking about sustainable power output (the energy for which
> must be derived aerobically).

I believe you misinterpret what VO2 max means. It is not the highest possible VO2 uptake that could
ever be attained by this individual. It is the highest attainable VO2 by that individual in his/her
current state of training. If it were possible to test VO2 max as you seemingly define it, it would
never be necessary to repeat it. VO2 max can be changed by athletes. It can be improved in young
athletes and it decreases as we get older (albeit slowly).

By virtue of your definition of VO2 Peak, it seems to me that you are accepting that VO2 uptake
(and, hence, VO2 max) depends greatly on the amount of muscle mass that is recruited.

Further, how on earth does one know one has actually tested "true" VO2 max as you define it. These
tests are always effort dependant and never truly objective. To say that cyclists can attain "true"
VO2 max goes against the facts as I understand them as I understand that triathletes frequently will
have higher measured VO2 max running than when cycling. Of course, in your mind triathletes are not
"trained cyclists" which would explain this discrepancy. That is not a sufficient explanation to me.

 

[Frank Day]

"Andy Coggan" <[email protected]> wrote in message news:<[email protected]>...
> "Frank Day" <[email protected]> wrote in message
> news:[email protected]...
>
> > I am sorry I am unfamiliar with the literature that seems to say this is impossible and my
> > knowedge of basic physics seems to have disappeared (I do think I had a little bit at one time).
>
> What's that saying? Oh yeah: ignorance has no excuse.

No, ignorance is bliss.
>
> > Oh well, I guess I will just have to remain the laughingstock of the scientific community (at
> > least, those in the know).
>
> Don't worry, you will.

After my company fails maybe I can get a job as a late-night toalk show host (gee, just what I need,
another career). I am sure you will write a recommendation for me. When I need it, I will ask.

 

[Frank Day]

"Andy Coggan" <[email protected]> wrote in message news:<[email protected]>...
> "Frank Day" <[email protected]> wrote in message
> news:[email protected]...
> > "Andy Coggan" <[email protected]> wrote in message
> news:<[email protected]>...
> > > "Frank Day" <[email protected]> wrote in message
> > > news:[email protected]...
> > >
> > > > the abilty to exercise is not limited by the heart or lungs but, rather, by the ability of
> > > > the muscles being exercised to extract oxygen from the blood. It is the muscles in the legs
> > > > and arms that go anaerobic (ischemia) and not the heart,
> > >
> > > And the reason, ultimately*, that the muscles fail is because the heart can't provide them
> > > with enough O2-carrying blood. This is proven by the
> fact
> > > that per mass of active tissue, both blood flow and O2 uptake are much higher during small
> > > muscle mass (e.g., one leg kicking) vs. large muscle mass exercise.
> >
> > It is true that the heart can't provide the tissues with enough O2 carrying blood, but this
> > isn't because the heart can't deliver more blood, but because there isn't enough capillary
> > density to deliver the blood flow required by the tissue.
>
> ******** - as I told you, per unit of active tissue muscle blood flow is as much as three-fold
> higher during small muscle mass exercise (e.g., 1 leg kicking) vs. large muscle mass exercise
> (e.g., cycling). This clearly demonstrates that there must be active vasocontriction even in
> exercising muscle, a point proven by studies using vasodilating drugs. The reason for this
> vasoconstriction is apparently to maintain blood pressure: since cardiac output cannot increase
> beyond that observed at/near VO2max, the body can't "allow" a large amount of muscle to fully
> vasodilate because then perfusion pressure would fall.

I would love to see that study that showed that a leg was able to do three times more work being
used alone than when being used in concert with the other. That would mean we should all be pedaling
with just one leg because 3 times 1 is more than 1 times 2. Or, was it just shown that blood flow
was increase but oxygen utilization wasn't. Or what. Blood flow is not power. Your study proves
nothing as regards this argument.
>
> As Loring Rowell put it: the heart's job during exercise is to maintain the highest possible blood
> pressure against the smallest possible peripheral resistance.
>
> >The heart can only deliver as much as the capillaries in the tissue will allow. If you train
> >harder you can develop more capillaries and more blood flow can ensue and performance will
> >increase. The heart adapts to this increased load. This is called training effect.
>
> While capillarization does increase with training, this is but one factor contributing to the
> improvements in VO2max/performance. More importantly, changes in capillarization are not required
> to achieve increases in VO2max. This is shown, e.g., by the fact that acutely increasing
> convective O2 deliverly via EPO administration, transfusion, hyperoxia, or even expansion of
> plasma volume (in an untrained person) increases VO2max w/o, obviously, any change in capillary
> density.

All you say doesn't change the fact that the ability to utilize oxygen is limited by the local
tissue conditions, which includes hemoglobin concentration, oxygen saturation, capillary density,
mitochondrial density, contractile element density, etc. etc. The healthy heart does not change,
affect or limit any of these things because it changes in concert with the same stimulation
(training). It always has a little in reserve. If it didn't, we would all risk death everytime we
exercised vigorously. If we were to transplant my heart in Lance Armstrong, I concede the heart
would be the limiting factor to his performance. Lucky for him he doesn't have my heart.

Frank

 

[Frank Day]

"Andy Coggan" <[email protected]> wrote in message news:<[email protected]>...
> "Frank Day" <[email protected]> wrote in message
> news:[email protected]...
> > "Andy Coggan" <[email protected]> wrote in message
> news:<[email protected]>...
> > > "Frank Day" <[email protected]> wrote in message
> > > news:[email protected]...
> > > > Even if pedal speed were allowed to vary and internal resistance were zero, this would not
> > > > become a peretual motion machine because it requires external energy to keep it going.
> > >
> > > Wrong. Wrong, wrong, wrong, wrong, and wrong.
> >
> > Show me the calculations of how it is possible to vary the pedaling speed to keep the energy of
> > the rider is constant when pedaling.
>
> Translation, please. Andrew Bradley was the one who said it was possible. I say it ain't.
>
> > Isn't a constant energy without input or loss both a necessary and sufficient condition for a
> > perpetual motion machine?
>
> Yes, it is.

Then, just look at the thighs during pedaling. they both pretty much cancel each other out from a
potential energy point of view, one going up when the other is going down. But, from a kinetic
energy point of view, they are both pretty much as maximum speed (albeit in opposite dierection but
that is of no consequence from an energy perspective because the velocity is squared) and both
pretty much at minimum speed (zero) at the same time. How on earth does one do things with the other
elements of the body to zero these out? it can't be done as far as I am concerned so even if all the
viscoelastic losses and bearing losses are zero, this is cannot be a perpetual motion machine.

Just account for the thighs please and I will come over to the dark side.

Frank

 

[Frank Day]

"Andy Coggan" <[email protected]> wrote in message news:<[email protected]>...
> "Terry Morse" <[email protected]> wrote in message news:tmorse-
> [email protected]...
> > Andy Coggan wrote:
> >
> > > Terry Morse wrote:
> > > > What changes in the body account for the other 50% of VO2max increase?
> > >
> > > Increased extraction of O2 from arterial blood.
> >
> > Okay, that extraction as I understand it shows up as a higher arterial-venous O2 difference (the
> > "a-vO2 diff" in the literature). But what's the physiological cause for that increase, an
> > increase in capillary density, or something else?
>
> An increase in perfused capillary bed volume may contribute to an increase in O2 extraction by
> increasing capillary mean transit time, thus allowing for more complete "unloading" of hemoglobin.
> However, as it turns out the percentage increase in capillary density tends to parallel quite
> closely the percentage increase in VO2max/maximal cardiac output - this suggests that capillary
> mean transit time is only maintained, not increased, as a result of training. This in turn implies
> that other factors must be operative as well, in particular a reduction in the mean intramuscular
> pO2 that helps "pull" more O2 from the blood. A lower intramuscular pO2 during maximal exercise
> after as compared to before training would be an expected consequence of having many more
> mitochondria* acting as O2 "sinks".
>
> *In reality, a more extensive mitochondrial reticulum...and since O2 is much more soluble in lipid
> membranes than in aqueous solutions, this detail may be a factor as well.

Look, from my (as I have recently come to understand) uninformed background it is really quite
simple. There are several things that come into play (which makes it not quite so simple in
practice). What is the energy use (what are the demands for oxygen by the mitochondria that are
making energy molecules necessary for muscle contraction?) that needs to be made up. What is the
furthest distance that oxygen must diffuse from the end capillary (where oxygen concentration is
lowest) to one of these active mitochodria. And, how much oxygen is in the blood (hemogglobin
concentration) which determines how fast it will drop as it passes through the capillaries. As
demand in the muscles increase, additional capillaries will open up, reducing the distance from the
active capillaries to to the mitochodria. Once they are all opened and once the concentration at the
end capillary drops to a point that the diffusion gradiant to the furthest away mitochodria is not
sufficient to supply the necessary amount of oxygen then anaerobic metabolism ensues in that
mitochondria (LT) and any additional effort just makes it worse and the end is near.

 

[Andrew Bradley]

[email protected] (Frank Day) wrote in message news:<[email protected]>...
> "Andy Coggan" <[email protected]> wrote in message
> news:<[email protected]>...
> > > > > Even if pedal speed were allowed to vary and internal resistance were zero, this would
> > > > > not become a peretual motion machine because it requires external energy to keep it
> > > > > going.
> > > >
> > > > Wrong. Wrong, wrong, wrong, wrong, and wrong.
> > >
> > > Show me the calculations of how it is possible to vary the pedaling speed to keep the energy
> > > of the rider is constant when pedaling.

Reminds me of the time I was with a bloke suffering from concussion. Every five minutes he would
ask, "What happened to me then?"

> > Translation, please.
>Andrew Bradley was the one who said it was possible. I say it ain't.

Your calculation is highly chainring dependent thats the point, leading to a fatal _underestimation_
of the losses in certain cases.

> >
> > > Isn't a constant energy without input or loss both a necessary and sufficient condition for a
> > > perpetual motion machine?
> >
> > Yes, it is.
>
> Then, just look at the thighs during pedaling. they both pretty much cancel each other out from a
> potential energy point of view, one going up when the other is going down. But, from a kinetic
> energy point of view, they are both pretty much as maximum speed (albeit in opposite dierection
> but that is of no consequence from an energy perspective because the velocity is squared) and both
> pretty much at minimum speed (zero) at the same time. How on earth does one do things with the
> other elements of the body to zero these out?

Your analysis is roughly correct, the low in energy occurs roughly at TDC/BDC, and the high at mid
stroke, so you fit a traditional elliptical to speed the legs up over tops and slow them down mid
stroke. Energy variation is reduced. What more do you want Frank???

Incidentally, there is a theory that Biopace (ie the opposite of traditional elliptical) was
designed to "smooth out" the drive to the wheel via mechanical energy "storage". The idea presumably
being that more mechanical energy is fed into the drivetrain where the muscles don't work much.

>it can't be done as far as I am concerned so even if all the viscoelastic losses and bearing losses
>are zero, this is cannot be a perpetual motion machine.

You presumably feel that some form of osmosis to the ether accounts for the energy loss. Chain off,
your model _is_ a perpetual motion machine (note the word "model").

Your calculations apply equally well to a system of steel rods and hinges with the hips firmly
stabilised and ankles locked. Why not build one and think about whether your method accounts for the
energy losses there. It is not a balanced flywheel as Phil points out, so it may not spin for long,
but the energy loss is via the hinges and bearings. Having contemplated modelling the losses in this
model you may not feel up to the task of modelling energy losses in real legs.

>Just account for the thighs please and I will come over to the dark
side.

The "energy saver" ring slows the thighs down where they move fastest. But don't overlook the lower
leg Frank, and don't overlook shoes, pedals and cranks. Consider this: if the funny ring that gives
zero mechanical energy variation turns out to be impractical, fit heavier pedals - the chainring
can then be rounder. By increasing pedal weight, the energy-saver can in theory be as round as you
want. Reductio ad absurdum for the energy-saving chainrings and by the same token your calculation
method, I feel.

Andrew Bradley

 

[Andrew Bradley]

Andrew Bradley <[email protected]> wrote in message
news:[email protected]...

>
> You presumably feel that some form of osmosis to the ether accounts for the energy loss. Chain
> off, your model _is_ a perpetual motion machine (note the word "model").

Let me add that chain ON , given a friction free drivetrain, a fixed wheel and life-like system
momentum (eg massive flywheel) your model gives a perpetual motion machine with real life crank
angular velocity profile.

Andrew Bradley