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MikeyOz
May 17th 06, 10:27 AM
was reading this on cool-running and thought that it might be of
interest to some people, I did not know the extent, but I know you can
exercise while in a lactate, certainly a little eye opening though, I
guess the more you train in that zone, the more your body gets used to
it.

> Lactic Acid Is Not Muscles' Foe, It's Fuel
> By GINA KOLATA
> Published: May 16, 2006
>
>
> Everyone who has even thought about exercising has heard the warnings
> about lactic acid. It builds up in your muscles. It is what makes your
> muscles burn. Its buildup is what makes your muscles tire and give
> out.
>
> Coaches and personal trainers tell athletes and exercisers that they
> have to learn to work out at just below their "lactic threshold," that
> point of diminishing returns when lactic acid starts to accumulate.
> Some athletes even have blood tests to find their personal lactic
> thresholds.
>
> But that, it turns out, is all wrong. Lactic acid is actually a fuel,
> not a caustic waste product. Muscles make it deliberately, producing it
> from glucose, and they burn it to obtain energy. The reason trained
> athletes can perform so hard and so long is because their intense
> training causes their muscles to adapt so they more readily and
> efficiently absorb lactic acid.
>
> The notion that lactic acid was bad took hold more than a century ago,
> said George A. Brooks, a professor in the department of integrative
> biology at the University of California, Berkeley. It stuck because it
> seemed to make so much sense.
>
> "It's one of the classic mistakes in the history of science," Dr.
> Brooks said.
>
> Its origins lie in a study by a Nobel laureate, Otto Meyerhof, who in
> the early years of the 20th century cut a frog in half and put its
> bottom half in a jar. The frog's muscles had no circulation — no source
> of oxygen or energy.
>
> Dr. Myerhoff gave the frog's leg electric shocks to make the muscles
> contract, but after a few twitches, the muscles stopped moving. Then,
> when Dr. Myerhoff examined the muscles, he discovered that they were
> bathed in lactic acid.
>
> A theory was born. Lack of oxygen to muscles leads to lactic acid,
> leads to fatigue.
>
> Athletes were told that they should spend most of their effort
> exercising aerobically, using glucose as a fuel. If they tried to spend
> too much time exercising harder, in the anaerobic zone, they were told,
> they would pay a price, that lactic acid would accumulate in the
> muscles, forcing them to stop.
>
> Few scientists questioned this view, Dr. Brooks said. But, he said, he
> became interested in it in the 1960's, when he was running track at
> Queens College and his coach told him that his performance was limited
> by a buildup of lactic acid.
>
> When he graduated and began working on a Ph.D. in exercise physiology,
> he decided to study the lactic acid hypothesis for his dissertation.
>
> "I gave rats radioactive lactic acid, and I found that they burned it
> faster than anything else I could give them," Dr. Brooks said.
>
> It looked as if lactic acid was there for a reason. It was a source of
> energy.
>
> Dr. Brooks said he published the finding in the late 70's. Other
> researchers challenged him at meetings and in print.
>
> "I had huge fights, I had terrible trouble getting my grants funded, I
> had my papers rejected," Dr. Brooks recalled. But he soldiered on,
> conducting more elaborate studies with rats and, years later, moving on
> to humans. Every time, with every study, his results were consistent
> with his radical idea.
>
> Eventually, other researchers confirmed the work. And gradually, the
> thinking among exercise physiologists began to change.
>
> "The evidence has continued to mount," said L. Bruce Gladden, a
> professor of health and human performance at Auburn University. "It
> became clear that it is not so simple as to say, Lactic acid is a bad
> thing and it causes fatigue."
>
> As for the idea that lactic acid causes muscle soreness, Dr. Gladden
> said, that never made sense.
>
> "Lactic acid will be gone from your muscles within an hour of
> exercise," he said. "You get sore one to three days later. The time
> frame is not consistent, and the mechanisms have not been found."
>
> The understanding now is that muscle cells convert glucose or glycogen
> to lactic acid. The lactic acid is taken up and used as a fuel by
> mitochondria, the energy factories in muscle cells.
>
> Mitochondria even have a special transporter protein to move the
> substance into them, Dr. Brooks found. Intense training makes a
> difference, he said, because it can make double the mitochondrial mass.
>
>
> It is clear that the old lactic acid theory cannot explain what is
> happening to muscles, Dr. Brooks and others said.
>
> Yet, Dr. Brooks said, even though coaches often believed in the myth of
> the lactic acid threshold, they ended up training athletes in the best
> way possible to increase their mitochondria. "Coaches have understood
> things the scientists didn't," he said.
>
> Through trial and error, coaches learned that athletic performance
> improved when athletes worked on endurance, running longer and longer
> distances, for example.
>
> That, it turns out, increased the mass of their muscle mitochondria,
> letting them burn more lactic acid and allowing the muscles to work
> harder and longer.
>
> Just before a race, coaches often tell athletes to train very hard in
> brief spurts.
>
> That extra stress increases the mitochondria mass even more, Dr. Brooks
> said, and is the reason for improved performance.
>
> And the scientists?
>
> They took much longer to figure it out.
>
> "They said, 'You're anaerobic, you need more oxygen,' " Dr. Brooks
> said. "The scientists were stuck in 1920."


--
MikeyOz

Michael Warner
May 17th 06, 10:42 AM
On Wed, 17 May 2006 19:27:01 +1000, MikeyOz wrote:

>> Lactic Acid Is Not Muscles' Foe, It's Fuel

Which says what about athletes like Lance Armstrong, who produce
much less lactic acid for the same effort as their competitors, and
do better? Perhaps they're better at using their primary energy
source, glycogen, and don't need its help.

--
Home page: http://members.westnet.com.au/mvw

Bleve
May 17th 06, 11:37 AM
MikeyOz wrote:
> was reading this on cool-running and thought that it might be of
> interest to some people, I did not know the extent, but I know you can
> exercise while in a lactate, certainly a little eye opening though, I
> guess the more you train in that zone, the more your body gets used to
> it.

Gina's a long way out of date, Mikey! The whole blood lactate thing
was turfed years ago, and it's only still floating around because a lot
of old coaching manuals are still in print. There's a lot more guesses
at what causes DOMS etc too, it's not blood lactate, which is, as is
pointed out in your cite, a fuel. It's also interesting to discuss the
various "thresholds" that persist in training folklore - anaerobic
thresholds, lactate thresholds etc. Most of these are pretty-much
********, it seems.

Have some fun. go googling for the lactate shuffle, it's quite
fascinating.

warrwych
May 17th 06, 11:37 PM
Bleve Wrote:
> MikeyOz wrote:
> > was reading this on cool-running and thought that it might be of
> > interest to some people, I did not know the extent, but I know you
> can
> > exercise while in a lactate, certainly a little eye opening though,
> I
> > guess the more you train in that zone, the more your body gets used
> to
> > it.
>
> Gina's a long way out of date, Mikey! The whole blood lactate thing
> was turfed years ago, and it's only still floating around because a
> lot
> of old coaching manuals are still in print. There's a lot more guesses
> at what causes DOMS etc too, it's not blood lactate, which is, as is
> pointed out in your cite, a fuel. It's also interesting to discuss
> the
> various "thresholds" that persist in training folklore - anaerobic
> thresholds, lactate thresholds etc. Most of these are pretty-much
> ********, it seems.
>
> Have some fun. go googling for the lactate shuffle, it's quite
> fascinating.


the latest theory is over accumulation of hydrogen. But don't ask any
of the exercise physes from the AIS about it - they known NUTHIN', or
so they claim.......

which indicates to me it's 1) political (ie we aint tellin' nobody what
we know) 2) related to funding opportunities (ie grants for research,
see point 1); 3) they really DON't know how the energy systems work,
but are afraid to admit it


--
warrwych

Bean Long
May 17th 06, 11:58 PM
Graham Lamb and George Stephenson at La Trobe Zoology recently showed
that adding lactic acid to fatigued rat(?) muscle fibres allowed them to
continue contracting as the lactate stimulated the electrical current
required to generate contraction. I think this was presented on "Catalyst"


--
Bean

Remove "yourfinger" before replying

Bean Long
May 18th 06, 12:00 AM
http://www.abc.net.au/catalyst/stories/s1314443.htm
--
Bean

Remove "yourfinger" before replying

warrwych
May 18th 06, 12:34 AM
http://www.cytosport.com/science/lacticacid.html

It's from the Cytosports supplements site, but provides some "food for
thought" (apologies for the bad pun).


--
warrwych

Bleve
May 18th 06, 01:28 AM
warrwych wrote:
> Bleve Wrote:
> > MikeyOz wrote:
> > > was reading this on cool-running and thought that it might be of
> > > interest to some people, I did not know the extent, but I know you
> > can
> > > exercise while in a lactate, certainly a little eye opening though,
> > I
> > > guess the more you train in that zone, the more your body gets used
> > to
> > > it.
> >
> > Gina's a long way out of date, Mikey! The whole blood lactate thing
> > was turfed years ago, and it's only still floating around because a
> > lot
> > of old coaching manuals are still in print. There's a lot more guesses
> > at what causes DOMS etc too, it's not blood lactate, which is, as is
> > pointed out in your cite, a fuel. It's also interesting to discuss
> > the
> > various "thresholds" that persist in training folklore - anaerobic
> > thresholds, lactate thresholds etc. Most of these are pretty-much
> > ********, it seems.
> >
> > Have some fun. go googling for the lactate shuffle, it's quite
> > fascinating.
>
>
> the latest theory is over accumulation of hydrogen. But don't ask any
> of the exercise physes from the AIS about it - they known NUTHIN', or
> so they claim.......

I know a number of pursuit riders who use bicarb as a buffer to keep H+
(or is it P+?) in control for a short time. Whether or not it works?
I dunno ...


>
> which indicates to me it's 1) political (ie we aint tellin' nobody what
> we know) 2) related to funding opportunities (ie grants for research,
> see point 1); 3) they really DON't know how the energy systems work,
> but are afraid to admit it

Here's more of the "rub" with sports "science" - too many secrets, too
much bluff and bull**** to cover up either a lack of knowledge, or some
performance enhancing technique that may let everyone else improve too.
And, there's plain old cheating too .. using secret/special training
techniques to launder doping-boosted performances.

Tamyka Bell
May 18th 06, 01:30 AM
MikeyOz wrote:
>
> was reading this on cool-running and thought that it might be of
> interest to some people, I did not know the extent, but I know you can
> exercise while in a lactate, certainly a little eye opening though, I
> guess the more you train in that zone, the more your body gets used to
> it.

On CR, they said it was new, published in NYTimes or something. I read
the same (almost word for word) article in US Runners World well over a
year ago, and kept a copy of it (around here somewhere...)

Tam

Vincent Patrick
May 18th 06, 03:17 PM
Bleve wrote:

>
> warrwych wrote:
>> Bleve Wrote:
>> > MikeyOz wrote:
>> > > was reading this on cool-running and thought that it might be of
>> > > interest to some people, I did not know the extent, but I know you
>> > can
>> > > exercise while in a lactate, certainly a little eye opening though,
>> > I
>> > > guess the more you train in that zone, the more your body gets used
>> > to
>> > > it.
>> >
>> > Gina's a long way out of date, Mikey! The whole blood lactate thing
>> > was turfed years ago, and it's only still floating around because a
>> > lot
>> > of old coaching manuals are still in print. There's a lot more guesses
>> > at what causes DOMS etc too, it's not blood lactate, which is, as is
>> > pointed out in your cite, a fuel. It's also interesting to discuss
>> > the
>> > various "thresholds" that persist in training folklore - anaerobic
>> > thresholds, lactate thresholds etc. Most of these are pretty-much
>> > ********, it seems.
>> >
>> > Have some fun. go googling for the lactate shuffle, it's quite
>> > fascinating.
>>
>>
>> the latest theory is over accumulation of hydrogen. But don't ask any
>> of the exercise physes from the AIS about it - they known NUTHIN', or
>> so they claim.......
>
> I know a number of pursuit riders who use bicarb as a buffer to keep H+
> (or is it P+?) in control for a short time. Whether or not it works?
> I dunno ...

<nerd>
It's pH, where if you remember high school, pH = -log([H+]). The
decription 'hydrogen' is most likely just a poorly reported reference to
the hydrogen ion concentration [H+]. In that case a high hydrogen level
would mean an acid build up, but not necessarily due to lactic acid.
</nerd>

Getting creative (I'm making this bit up), the term 'hydrogen' might even be
used as a measure of the reducing-oxidising (redox) potential in the muscle
cell environment. In that case a 'high hydrogen level' might be used to
describe a lack of available oxygen species which are energy rich, and an
excess of reduced species which are energy poor.

Notice no mention of ATP, ADP, mitochondria, or how your enzymes change with
training. If you want to know more, there is quite a bit of information on
the web, such as the old-ish but readable overview at:
http://www.cytosport.com/science/lacticacid.html

Cheers,

Vince
"Please don't get me started on chemistry"

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