Beware of PowerCranks



Andy Coggan wrote:
> On Jun 7, 6:35 pm, Howard Kveck <[email protected]> wrote:
>> In article <[email protected]>,
>> Andy Coggan <[email protected]> wrote:
>>
>>> eucapnic
>> First use of this word in this group (rbr).
>
> Seriously? Man, that's sad.
>
> Andy Coggan
>
Webster's doesn't have it (I checked) and Google comes up with some
strange hits, but it is most definitely not a mainstream word.
Not in the states, at least.
Bill Baka
 
In article
<[email protected]>,
Andy Coggan <[email protected]> wrote:

> Fact: CO2 plays only a very limited role in regulating ventilation
> during exercise.

Where is this fact documented? Blood CO2 level has a
profound effect on ventilation. There is a mechanism in
the brain that senses blood pH. When pH falls the
mechanism increases breathing rate. When pH rises the
mechanism decreases breathing rate. It is a dominant
mechanism as is evident from the phenomenon known as
Cheyne-Stokes respiration where the feed-back mechanism
is involved in a pathological oscillation of breathing rate.

--
Michael Press
 
"Bill" <[email protected]> wrote in message
news:g%[email protected]...
> Carl Sundquist wrote:
>>
>> "Bill" <[email protected]> wrote in message
>> news:[email protected]...
>>
>>> Not judging by the quality of doctors in my corner of the world.
>>> I was just thinking that VO2 max might be due to a more efficient
>>> whole body system than just lung capacity. That takes my 30 second
>>> full blast runs out of the equation then. Is there an equivalent
>>> bicycle event like a quarter mile drag race that would be the equal
>>> in terms of full burner on the legs and wait for the pulse and lungs
>>> to catch up?
>>
>> It's called a Wingate test.
>
> I just looked it up and that might be why my full tilt runs always run
> out of gas at about 30 seconds. That's also about my maximum full out
> attack time on the bike.
> Interesting stuff, so now I have some reading to do.
> Bill Baka

You asked about an event. For the over 50s on the track, there is the
500m which from a standing start runs some 37 seconds or so depending on
your ability. Talk about eyeballs out.

Phil H
 
"Michael Press" <[email protected]> wrote in message
news:[email protected]...
> In article
> <[email protected]>,
> Andy Coggan <[email protected]> wrote:
>
>> Fact: CO2 plays only a very limited role in regulating ventilation
>> during exercise.
>
> Where is this fact documented? Blood CO2 level has a
> profound effect on ventilation. There is a mechanism in
> the brain that senses blood pH. When pH falls the
> mechanism increases breathing rate. When pH rises the
> mechanism decreases breathing rate. It is a dominant
> mechanism as is evident from the phenomenon known as
> Cheyne-Stokes respiration where the feed-back mechanism
> is involved in a pathological oscillation of breathing rate.
>
My understanding for strenous exercise is, there are the initial
collateral impulses which stimulate both the contracting muscles and the
respiratory center. There is actually an initial drop in PCO2. However
after about a minute when PCO2 reaches normal levels again, the
mechanism which you mention kicks in. PCO2 being the main driver over pH
and O2.

Phil H
 
"Andy Coggan" <[email protected]> wrote in message
news:[email protected]...
> On Jun 7, 11:35 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>> "Andy Coggan" <[email protected]> wrote in message
>>
>> news:[email protected]...
>>
>>
>>
>> > On Jun 3, 9:01 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>> >> "A Muzi" <[email protected]> wrote in message
>>
>> >>news:[email protected]...
>>
>> >> >>>>> Ride Faster <[email protected]> wrote:
>> >> >>>>>> I had the same experience with PowerCranks. This product
>> >> >>>>>> is
>> >> >>>>>> garbage.
>>
>> >> >>>> "[email protected]" <[email protected]> wrote:
>> >> >>>>> It's really outrageous for them Powercrank to charge so much
>> >> >>>>> for a
>> >> >>>>> faulty design.
>>
>> >> >>> "Tim McNamara" <[email protected]> wrote
>> >> >>>> The proprietor of PowerCranks used to post here to rebut
>> >> >>>> criticisms, but
>> >> >>>> I haven't seen anything from him for a while. Basically I
>> >> >>>> suspect
>> >> >>>> that
>> >> >>>> the price is high because (1) he promises that his product
>> >> >>>> will
>> >> >>>> make you
>> >> >>>> faster for which competitive people will pay lots of money
>> >> >>>> and
>> >> >>>> (2)
>> >> >>>> his
>> >> >>>> business is small enough that he doesn't get much by way of
>> >> >>>> economies of
>> >> >>>> scale to bring his production costs down.
>>
>> >> >> "Phil Holman" <piholmanc@yourservice> wrote:
>> >> >>> Frank Day. His last posts here were after a scientific study
>> >> >>> showed
>> >> >>> a statistically significant 1.5% gross efficiency improvement.
>> >> >>> The
>> >> >>> experts here still wouldn't buy it.
>>
>> >> > [email protected] wrote:
>> >> >> No offense, but that sounds like 200 watts rising to 203 watts.
>>
>> >> > Wouldn't that be 200W reduced to a mere 197 watts?
>>
>> >> No, but I know what you are getting at. For the same 200 watt
>> >> output,
>> >> VO2 consumption reduces by 100*1.5/E = approx 6% less. From this
>> >> we
>> >> infer that for the same O2 consumption, the athlete can output 212
>> >> watts.
>>
>> > Can that be safely inferred?
>>
>> I don't think it's too much of a stretch for a very small
>> extrapolation.
>
> Actually, it is, because if efficiency were everything, we'd all be
> riding at much slower cadences than we normally do.

That just confuses the issue; we are not talking about a race to burn
fewest calories and the example used was at 70% effort. Anyhow, who
would pass up being more efficient at their max sustainble power output
and normal cadence etc.(which I know doesn't read over from this test
result).
>
> "The best predictor of performance is performance itself"

And no one is interested in why?

Phil H
 
Phil Holman wrote:
> "Bill" <[email protected]> wrote in message
> news:g%[email protected]...
>> Carl Sundquist wrote:
>>> "Bill" <[email protected]> wrote in message
>>> news:[email protected]...
>>>
>>>> Not judging by the quality of doctors in my corner of the world.
>>>> I was just thinking that VO2 max might be due to a more efficient
>>>> whole body system than just lung capacity. That takes my 30 second
>>>> full blast runs out of the equation then. Is there an equivalent
>>>> bicycle event like a quarter mile drag race that would be the equal
>>>> in terms of full burner on the legs and wait for the pulse and lungs
>>>> to catch up?
>>> It's called a Wingate test.
>> I just looked it up and that might be why my full tilt runs always run
>> out of gas at about 30 seconds. That's also about my maximum full out
>> attack time on the bike.
>> Interesting stuff, so now I have some reading to do.
>> Bill Baka
>
> You asked about an event. For the over 50s on the track, there is the
> 500m which from a standing start runs some 37 seconds or so depending on
> your ability. Talk about eyeballs out.
>
> Phil H
>
>
I just did it again, and I am waaay over 50, like 58, and didn't really
have to start heavy breathing until I was at about the 1,000 foot
finish. Of course I was still huffing and puffing all the way back, and
the really heavy breathing was only about 30 seconds after I was done
running. Eyeballs out almost describes it though, but I will run as long
as I am able, like maybe 90 or so, and the same with riding a bicycle.
My sister is 72 and still rides on occasion, but not regularly.
The trip odometer on my bike reads about 0.21 miles to the last point I
measured and I just went past that today on my second run. My runs may
or may not be as good as an hour long bike ride but I figure anything
that gets your heart working is a good thing.
Bill Baka
 
Tim McNamara wrote:
> In article <[email protected]>,
> Andy Coggan <[email protected]> wrote:
>
>> On Jun 7, 6:35 pm, Howard Kveck <[email protected]> wrote:
>>> In article <[email protected]>,
>>> Andy Coggan <[email protected]> wrote:
>>>
>>>> eucapnic
>>> First use of this word in this group (rbr).
>> Seriously? Man, that's sad.
>
> But isn't it correctly spelled "eucapneic?" There are at least zero
> hits on Google for "eucapnic" and 309 hits for "eucapneic."


http://www.merriam-webster.com/dictionary/eucapneic

Not found here.
Is this an intentional wild goose chase?
BB
 
On Fri, 08 Jun 2007 19:39:40 -0500, Tim McNamara
<[email protected]> wrote:

>In article <[email protected]>,
> Andy Coggan <[email protected]> wrote:
>
>> On Jun 7, 6:35 pm, Howard Kveck <[email protected]> wrote:
>> > In article <[email protected]>,
>> > Andy Coggan <[email protected]> wrote:
>> >
>> > > eucapnic
>> >
>> > First use of this word in this group (rbr).
>>
>> Seriously? Man, that's sad.
>
>But isn't it correctly spelled "eucapneic?" There are at least zero
>hits on Google for "eucapnic" and 309 hits for "eucapneic."

Dear Tim,

Try the related eucapnia:

http://cancerweb.ncl.ac.uk/cgi-bin/omd?query=eucapnia&action=Search+OMD

Cheers,

Carl Fogel
 
"Phil Holman" <piholmanc@yourservice> wrote in message
news:[email protected]...
>
> "Michael Press" <[email protected]> wrote in message
> news:[email protected]...
>> In article
>> <[email protected]>,
>> Andy Coggan <[email protected]> wrote:
>>
>>> Fact: CO2 plays only a very limited role in regulating ventilation
>>> during exercise.
>>
>> Where is this fact documented? Blood CO2 level has a
>> profound effect on ventilation. There is a mechanism in
>> the brain that senses blood pH. When pH falls the
>> mechanism increases breathing rate. When pH rises the
>> mechanism decreases breathing rate. It is a dominant
>> mechanism as is evident from the phenomenon known as
>> Cheyne-Stokes respiration where the feed-back mechanism
>> is involved in a pathological oscillation of breathing rate.
>>
> My understanding for strenous exercise is, there are the initial
> collateral impulses which stimulate both the contracting muscles and the
> respiratory center. There is actually an initial drop in PCO2. However
> after about a minute when PCO2 reaches normal levels again, the mechanism
> which you mention kicks in. PCO2 being the main driver over pH and O2.

When your cellular and blood levels of CO2 rise you begin breathing faster.
Unfortunately for you, oxygen has a high priority in your blood stream and
so as you breath harder your expiration of CO2 remains pretty much constant
despite increased demand. As you breath harder the blood picks up more
oxygen and takes up all the space that CO2 wants.

So all that puffing and panting isn't to get more oxygen but to get rid of
more CO2.
 
In article <[email protected]>,
Bill <[email protected]> wrote:

> Tim McNamara wrote:
> > In article <[email protected]>,
> > Andy Coggan <[email protected]> wrote:
> >
> >> On Jun 7, 6:35 pm, Howard Kveck <[email protected]>
> >> wrote:
> >>> In article
> >>> <[email protected]>,
> >>> Andy Coggan <[email protected]> wrote:
> >>>
> >>>> eucapnic
> >>> First use of this word in this group (rbr).
> >> Seriously? Man, that's sad.
> >
> > But isn't it correctly spelled "eucapneic?" There are at least
> > zero hits on Google for "eucapnic" and 309 hits for "eucapneic."
>
> http://www.merriam-webster.com/dictionary/eucapneic
>
> Not found here. Is this an intentional wild goose chase?

No. "--pnea" is a stem word related to breathing, coming from the Greek
word "pneuma" IIRC. Used mainly in medical parlance, such as "apnea"
(as in "sleep apnea) and "dyspnea." "Ecucapneic" or "dyspneic" would be
the state of eucapnia or dysnpea. In medical terms the prefix "eu--"
generally means "normal:" euthyroid, euthymic, etc. Eucapnea appears
to be having a PC02 in the normal range.

"Pneumonia" is a related word, as are "pneumatic tires."
 
On 25 May 2007 20:47:35 -0700, [email protected] wrote:

>[snip]

Great advice. I'd add also that people should:

Beware of looking like an idiot by feeding a Crossposted Troll
 
Tim McNamara wrote:
> In article <[email protected]>,
> Bill <[email protected]> wrote:
>
>> Tim McNamara wrote:
>>> In article <[email protected]>,
>>> Andy Coggan <[email protected]> wrote:
>>>
>>>> On Jun 7, 6:35 pm, Howard Kveck <[email protected]>
>>>> wrote:
>>>>> In article
>>>>> <[email protected]>,
>>>>> Andy Coggan <[email protected]> wrote:
>>>>>
>>>>>> eucapnic
>>>>> First use of this word in this group (rbr).
>>>> Seriously? Man, that's sad.
>>> But isn't it correctly spelled "eucapneic?" There are at least
>>> zero hits on Google for "eucapnic" and 309 hits for "eucapneic."
>> http://www.merriam-webster.com/dictionary/eucapneic
>>
>> Not found here. Is this an intentional wild goose chase?
>
> No. "--pnea" is a stem word related to breathing, coming from the Greek
> word "pneuma" IIRC. Used mainly in medical parlance, such as "apnea"
> (as in "sleep apnea) and "dyspnea." "Ecucapneic" or "dyspneic" would be
> the state of eucapnia or dysnpea. In medical terms the prefix "eu--"
> generally means "normal:" euthyroid, euthymic, etc. Eucapnea appears
> to be having a PC02 in the normal range.
>
> "Pneumonia" is a related word, as are "pneumatic tires."

I kind of was suspicious of the apne part of it since I have insomnia
and my doctor had me do a sleep study where they checked for apnea,
which I told him I did NOT have. He said I had to do it or be put down
as refusing treatment. Pneu is familiar since I have a lot of air
powered tools and a compressor. Putting the eu before the rest
definitely took me on a mental detour.
Your explanation does make sense, even if it is not in the Webster's
dictionary.
Bill Baka
 
In article <[email protected]>,
Bill <[email protected]> wrote:

> Tim McNamara wrote:
> > In article <[email protected]>,
> > Bill <[email protected]> wrote:
> >
> >> Tim McNamara wrote:
> >>> In article
> >>> <[email protected]>,
> >>> Andy Coggan <[email protected]> wrote:
> >>>
> >>>> On Jun 7, 6:35 pm, Howard Kveck <[email protected]>
> >>>> wrote:
> >>>>> In article
> >>>>> <[email protected]>,
> >>>>> Andy Coggan <[email protected]> wrote:
> >>>>>
> >>>>>> eucapnic
> >>>>> First use of this word in this group (rbr).
> >>>> Seriously? Man, that's sad.
> >>> But isn't it correctly spelled "eucapneic?" There are at least
> >>> zero hits on Google for "eucapnic" and 309 hits for "eucapneic."
> >> http://www.merriam-webster.com/dictionary/eucapneic
> >>
> >> Not found here. Is this an intentional wild goose chase?
> >
> > No. "--pnea" is a stem word related to breathing, coming from the
> > Greek word "pneuma" IIRC. Used mainly in medical parlance, such as
> > "apnea" (as in "sleep apnea) and "dyspnea." "Ecucapneic" or
> > "dyspneic" would be the state of eucapnia or dysnpea. In medical
> > terms the prefix "eu--" generally means "normal:" euthyroid,
> > euthymic, etc. Eucapnea appears to be having a PC02 in the normal
> > range.
> >
> > "Pneumonia" is a related word, as are "pneumatic tires."
>
> I kind of was suspicious of the apne part of it since I have insomnia
> and my doctor had me do a sleep study where they checked for apnea,
> which I told him I did NOT have. He said I had to do it or be put
> down as refusing treatment.

You wouldn't know whether you have sleep apnea (there are two types:
obstructive sleep apnea which is caused mechanically by closing of the
airway; and central sleep apnea which is neurologically caused) as
you're asleep at the time. Anyone you sleep with would probably know,
however. If you're awake and aware of being awake, however, that's
usually not sleep apnea.

http://www.nlm.nih.gov/medlineplus/ency/article/003997.htm

A friend of mine was diagnosed about 10 years ago with OSA. He had been
chronically tired with low energy and thought he was depressed. The OSA
was diagnosed and he was given a CPAP machine- it was amazing from the
very first night he used it. He was energetic and happy and about 50
times more active than he was. His motivation was so much better than
he got a new job that just about doubled his income. I was just
astonished at the difference. Basically he operated with a serious
sleep deficit for years.

There are many causes of insomnia: depression, anxiety, bipolar
disorder, substance abuse, breathing disorders, pain, etc. etc. When
all those are ruled out then there is "primary insomnia:"

http://www.emedicine.com/med/topic3128.htm

> Pneu is familiar since I have a lot of air powered tools and a
> compressor. Putting the eu before the rest definitely took me on a
> mental detour. Your explanation does make sense, even if it is not in
> the Webster's dictionary.

I find "acapnia" in the NIH online medical dictionary but not "eucapnea"
or "eucapnia." That's despite the fact that the term is found in
literature searches. Odd. Obviously not a commonly used word even in
medicine.
 
Tim McNamara wrote:
> In article <[email protected]>,
> Bill <[email protected]> wrote:
>> I kind of was suspicious of the apne part of it since I have insomnia
>> and my doctor had me do a sleep study where they checked for apnea,
>> which I told him I did NOT have. He said I had to do it or be put
>> down as refusing treatment.
>
> You wouldn't know whether you have sleep apnea (there are two types:
> obstructive sleep apnea which is caused mechanically by closing of the
> airway; and central sleep apnea which is neurologically caused) as
> you're asleep at the time. Anyone you sleep with would probably know,
> however. If you're awake and aware of being awake, however, that's
> usually not sleep apnea.
>
> http://www.nlm.nih.gov/medlineplus/ency/article/003997.htm

I don't have apnea and knew it before going in for the test. I had an
arrogant doctor that insisted he knew more about my insomnia than I do.
He is no longer working in this area, so that tells me my opinion of him
must have been shared by other patients.
>
> A friend of mine was diagnosed about 10 years ago with OSA. He had been
> chronically tired with low energy and thought he was depressed. The OSA
> was diagnosed and he was given a CPAP machine- it was amazing from the
> very first night he used it. He was energetic and happy and about 50
> times more active than he was. His motivation was so much better than
> he got a new job that just about doubled his income. I was just
> astonished at the difference. Basically he operated with a serious
> sleep deficit for years.
>
> There are many causes of insomnia: depression, anxiety, bipolar
> disorder, substance abuse, breathing disorders, pain, etc. etc. When
> all those are ruled out then there is "primary insomnia:"
>
> http://www.emedicine.com/med/topic3128.htm

Bingo!
Falling asleep at all is my problem but once I get to sleep I am out for
a good 4 hours at a time. Really deep sleep seems to be beyond me since
I am usually in REM, or I have marathon dreams in high speed. Even after
riding and hiking around 100 miles I am not tired enough to just drop
off like many people can do.
It's total frustration.
I missed a cycling event this year due to falling asleep about the time
I was supposed to be getting up.
>
>> Pneu is familiar since I have a lot of air powered tools and a
>> compressor. Putting the eu before the rest definitely took me on a
>> mental detour. Your explanation does make sense, even if it is not in
>> the Webster's dictionary.
>
> I find "acapnia" in the NIH online medical dictionary but not "eucapnea"
> or "eucapnia." That's despite the fact that the term is found in
> literature searches. Odd. Obviously not a commonly used word even in
> medicine.

Ummm, correct. There are very few words I have never heard of since my
mother was a poet and my father worked as a newspaper proofreader and
printer. My sister, older, always had fun nailing me with big words,
too. Reading the Dictionary was my best defense.
Bill Baka
 
On Jun 7, 11:57 am, Andy Coggan <[email protected]> wrote:
> On Jun 5, 11:04 pm, "Phil Holman" <piholmanc@yourservice> wrote:
>
> > <[email protected]> wrote in message
> > > In recent times, steam RR locomotives, although not rated in Horse
> > > Power (but rather "tractive effort", the pull at which the wheels
> > > would spin) had a conversion chart to HP based on grate area in the
> > > fire box which governs how much heat can be transferred to steam in
> > > the boiler. Grate area is closely similar to lung displacement for
> > > physically fit racers. That is what limits climbing or TT ability,
> > > not ankling, pedaling style or other external means.
>
> > You continue to repeat this misconception. Lung displacement or lung
> > capacity is not the limiting factor in climbing or TTing or cycling in
> > general. If you understood the cause and effect elements you would
> > understand that extreme "out of breath" is caused by excess CO2 in the
> > blood stream as a result of lactic buffering.
>
> Great! Now we have one engineer feeding misconceptions about how
> physiology functions to another engineer...

No, now we have an exercise physiologist trying to correct someone
with a correct understanding of the limiter. I am truly amazed that
you haven't figured out what is going on here yet.

>
> Fact: CO2 plays only a very limited role in regulating ventilation
> during exercise.

Fact: There are two main drivers for ventilation. CO2 and O2. The main
one is CO2. The body adjusts ventilation to maintain the arterial
partial pressure of CO2 at 40torr. CO2 is the prime determiner of
ventilatory function at all times except during extreme hypoxia, which
never occurs during normal exercise.

>
> > That is, the limits of
> > aerobic capacity were reached upstream (cardiac output, blood muscle
> > interface limitations etc) and no further limitations are imposed by the
> > lungs. It wouldn't matter if you doubled lung capacity, blood lactate
> > concentrations wouldn't change and this is the culminating event in
> > limiting aerobic performance. Heavy breathing is an effect not a cause.
>
> In fact, mild-to-moderate arterial desaturation tends to occur during
> maximal exercise in a significant portion of the population (at least
> discounting young, healthy, untrained men!), indicating that, at least
> to some extent, aerobic capacity (i.e., VO2max) is limited, in part,
> by pulmonary function.
>
> Andy Coggan

Phoeey. A small arterial desaturation is most likely explained by
increased left to right shunting and ventilation perfusion mismatch at
the extremes and is probably has no effect on performance because of
the oxyhemoglobin saturation curve. There could be other explanations
also such as a shift in the curve due to changes in pH. Small levels
of desaturation have almost no effect on oxygen carrying capacity to
the tissues.
 
In article <[email protected]>,
[email protected] wrote:

> On Jun 7, 11:57 am, Andy Coggan <[email protected]> wrote:
>
> > In fact, mild-to-moderate arterial desaturation tends to occur
> > during maximal exercise in a significant portion of the population
> > (at least discounting young, healthy, untrained men!), indicating
> > that, at least to some extent, aerobic capacity (i.e., VO2max) is
> > limited, in part, by pulmonary function.
>
> Phoeey. A small arterial desaturation is most likely explained by
> increased left to right shunting

Left to right shunting from where to where through what? This term is
usually used to indicate left to right shunting through an atrial septal
defect or cases of tricuspid atresia. There should be little or no left
to right shunting through a patent foramen ovale and should be no
shunting at all in a normal heart. So I am not clear to what you refer.
Thanks.
 
On Jul 30, 2:53 pm, Tim McNamara <[email protected]> wrote:
> In article <[email protected]>,
>
> [email protected] wrote:
> > On Jun 7, 11:57 am, Andy Coggan <[email protected]> wrote:
>
> > > In fact, mild-to-moderate arterial desaturation tends to occur
> > > during maximal exercise in a significant portion of the population
> > > (at least discounting young, healthy, untrained men!), indicating
> > > that, at least to some extent, aerobic capacity (i.e., VO2max) is
> > > limited, in part, by pulmonary function.
>
> > Phoeey. A small arterial desaturation is most likely explained by
> > increased left to right shunting
>
> Left to right shunting from where to where through what? This term is
> usually used to indicate left to right shunting through an atrial septal
> defect or cases of tricuspid atresia. There should be little or no left
> to right shunting through a patent foramen ovale and should be no
> shunting at all in a normal heart. So I am not clear to what you refer.
> Thanks.

My bad, I should have said increased right to left shunting although
this is not so much as a physiological shunt but as a ventilation
perfusion defect behaving as a shunt.
 
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