Beware of PowerCranks

On Jun 6, 12:42 am, "Phil Holman" piholmanc@yourservice wrote:

BTW, do you ever discuss the gastric freezing debacle in your class?
When I used to teach intro I used that as my cautionary tale for RCTs
(I used tuberculous meningitis as my counter-example).

No, and searching through some articles it looks to be very
controversial. Is it universally resolved yet?

You mean gastric freezing? Yup. One of the side-effects is that
nowadays it's generally required that medical researchers declare
their potential conflicts of interest, like whether they own the
company making the gastric freezing machines. Or did you mean the
ethical line of when to do placebo controls? That's not universally
resolved. Remember the fast-tracking that HIV activists wanted the FDA
to do? Much of that fast-tracking was about whether placebo controls
were necessary.

Tim McNamara wrote:
Ummm. What? Ah. Circumcision.

Cosmetic ? Don't tell me this is another helmet thread.

Tim McNamara wrote:
In article ,
Bill wrote:

Now, sneaking in a question, does one full blast run per day make any
difference compared to a few hours on the bike? I'm thinking heart
condition mainly on this.

The literature I have seen in the last year or two has indicated that
sprint training has significant benefits for endurance. I don't think
your heart can tell if you're running or riding a bike.

Probably not, but my legs sure feel the difference. It could be geometry
related since I ride 3 different bikes. They all fit pretty good but
none is a custom fit. I think I can stay heart healthy with my 2 minute
blasts as opposed to watching television or sitting here at the computer.
I guess anything that raises you heart rate for a while is a good thing.
I try to get the run in first and then do the bike ride and when I get
home I sometimes do the run again.
I just hope that is a good plan.
Bill Baka

In article
,
Bill wrote:

I don't want to make a 'me' thing out of this post

Yes, you do.

--
Michael Press

In article
,
"Phil Holman" piholmanc@yourservice wrote:

wrote in message
...
Phil Holman writes:

Wouldn't that argument mean that if you did observe a change in
VO2Max (in ml/kg/min) then the previous value was faulty and
shouldn't be used as a basis for comparison? If one subscribed
to that argument, both the improvement and VO2Max and the
improvement in power should be discounted.

It depends on the definition of VO2max. I don't see how something
like this could be so fixed.

Yeah, I was engaging in Socratic dialog. I don't think VO2Max is
that fixed, either -- in part because of the kg vs. "lean" kg
issue. OTOH, one does have to worry about how well the initial
tests were done. Which sort of argues in favor of RCTs.

BTW, do you ever discuss the gastric freezing debacle in your
class? When I used to teach intro I used that as my cautionary
tale for RCTs (I used tuberculous meningitis as my
counter-example).

No, and searching through some articles it looks to be very
controversial. Is it universally resolved yet? For the success
stories we do the Linus Pauling vitamin C to prevent colds and the
largest medical experiment of all time with the Salk vaccine.

It's a shock to students when they see the higher contracted numbers
of polio in the placebo group. "You mean, if they had given the
vaccine to everyone there would be a couple of hundred less children
who contracted polio." Errrm.

This whole subject reappear under new guises because people do not
want to believe that there is a direct relationship between aerobic
capacity and performance on a bicycle.

Here we go again.


I spent years reading how ankling would improve climbing and top speed
and that it needed to be practiced diligently. That went away only to
be replaced by other beliefs that we can fabricate power by trickery.

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. 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.

As I understand it the proximate cause is mitochondrial
respiration rate overload. Cellular ATP hydrolysis in
excess of the mitochondrial respiration rate increases
H+ in the cell.

--
Michael Press

In article
.net
,
"Tom Kunich" cyclintom@yahoo. com wrote:

"Phil Holman" piholmanc@yourservice wrote in message
. ..

wrote in message
...
Phil Holman writes:

Wouldn't that argument mean that if you did observe a change in
VO2Max (in ml/kg/min) then the previous value was faulty and
shouldn't be used as a basis for comparison? If one subscribed
to that argument, both the improvement and VO2Max and the
improvement in power should be discounted.

It depends on the definition of VO2max. I don't see how something
like this could be so fixed.

Yeah, I was engaging in Socratic dialog. I don't think VO2Max is
that fixed, either -- in part because of the kg vs. "lean" kg
issue. OTOH, one does have to worry about how well the initial
tests were done. Which sort of argues in favor of RCTs.

BTW, do you ever discuss the gastric freezing debacle in your
class? When I used to teach intro I used that as my cautionary
tale for RCTs (I used tuberculous meningitis as my
counter-example).

No, and searching through some articles it looks to be very
controversial. Is it universally resolved yet? For the success
stories we do the Linus Pauling vitamin C to prevent colds and the
largest medical experiment of all time with the Salk vaccine.

It's a shock to students when they see the higher contracted numbers
of polio in the placebo group. "You mean, if they had given the
vaccine to everyone there would be a couple of hundred less children
who contracted polio." Errrm.

This whole subject reappear under new guises because people do not
want to believe that there is a direct relationship between aerobic
capacity and performance on a bicycle.

Here we go again.


I spent years reading how ankling would improve climbing and top speed
and that it needed to be practiced diligently. That went away only to
be replaced by other beliefs that we can fabricate power by trickery.

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. 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.

As proof of what Phil has to say about this - when you're staggeringly out
of breath and can hardly move your blood oxygen is still more than 90%.
Normal blood oxygen runs about 98%.

I have an ex-brother in law who was the longest surviving person without a
main coronary artery. Until he got a partial heart transplant in 1999 his
blood oxygen was normally 70% or less. Proof that blood oxygen is NOT the
problem in climbing - rather lactac and excess CO2 is. BTW - he's still
alive at about 55 years old now.

No, lactate is not the problem.
You should know because you posted this URL:
URL:http://ajpregu.physiology.org/cgi/content/full/287/3/R502

--
Michael Press

Michael Press wrote:
In article
,
Bill wrote:

I don't want to make a 'me' thing out of this post

Yes, you do.

There's no "me" in "team".

In article ,
says...
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.

Are you sure enough to stand behind that 100%. My lung capacity has not
changed since last years summer, but my conditioning has gotten rather
lax due to a winter spent more with the computer than the bike. I
definitely can't climb as well as last summer and it isn't due to lung
capacity. Want to rethink that one? There is also the ability to use
what air you do take in with each breath and the amount of reserve
energy in your legs.
I'm waiting for the big equation now. ;)
Bill Baka

I think he's saying that lung capacity is what *ultimately* limits your
aerobic capabilities for climing or TT'ing, when you are at the best
physical condition your genetics allow you to be. If you haven't been
training, then other things will limit you before you max out your lung
capacity.

--
Remove the ns_ from if replying by e-mail (but keep posts in the
newsgroups if possible).

In article ,
Donald Munro wrote:

Tim McNamara wrote:
Ummm. What? Ah. Circumcision.

Cosmetic ? Don't tell me this is another helmet thread.

LOL! Circumcision is actually a controversial procedure even though
it's taken for granted. For one thing, it is generally done without
anesthesia under the myth that infants don't feel pain. For another,
the owner of the penis is not consulted before the procedure is done.
And for a third, the procedure is really quite unnecessary. It's done
mainly out of mindless tradition, although there are of course multiple
religions that practice circumcision for various hygienic or other
faith-based reasons.

Some people get quite perturbed about the subject and consider it to be
genital mutilation and a human rights issue. Some of the threads I have
seen on the topic are far more intense than any helmet thread.

"Tim McNamara" wrote in message news:timmcn-
....
Some people get quite perturbed about the subject and consider it to be
genital mutilation and a human rights issue. Some of the threads I have
seen on the topic are far more intense than any helmet thread.

Think how intense it would be if infants could post. Probably talk like it
was all about them...


--
Curtis L. Russell
Odenton, MD (USA)
Just someone on two wheels...