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I heart team Zissou!
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All you thought you knew about lactic acid (and LT training) might be wrong....

back to the drawing board...or not. read on.

As published by the New York Times:

Lactic Acid Is Not Muscles' Foe, It's Fuel
By GINA KOLATA
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."
 

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You know back in my "uneducated" MTB riding days I thought lactic acid built up in your legs mainly when you were really slowly grinding away and dropping into an easier gear to spin it out was a way to get rid of it, which actually seemed to work for me for some reason. I guess it could have just been a placebo effect but now I'm starting to wonder about that, maybe that has something to do with why LA spins up climbs?
 

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jaseone said:
You know back in my "uneducated" MTB riding days I thought lactic acid built up in your legs mainly when you were really slowly grinding away and dropping into an easier gear to spin it out was a way to get rid of it, which actually seemed to work for me for some reason. I guess it could have just been a placebo effect but now I'm starting to wonder about that, maybe that has something to do with why LA spins up climbs?
Just because lactate isn't bad does not mean that its build up in the blood is not a good indicator. - TF
 

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Lance spins up climbs because spinning uses relatively more aerobic muscle fibers, rather than the fast-twitch fibers that can produce a great deal of power but fatigue faster. There is some overlap with why cars with smaller engines generally run at higher rev's -- the power is derived from many revolutions of the crank or the camshaft rather than, in a bike, slow, torquey revolutions or, in a car, slow torquey movements of big pistons.
Lance's lactic threshold is sky-high. What this means is that, with his huge aerobic engine, his muscles create lots of power without having to resort to anaerobic metabolism. It's not that lactic acid is bad for you, but it does signal that your muscles are working near their capacity. Lance doesn't much need to resort to anaerobic metabolism, because he's got such efficient aerobic metabolism.
 

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jaded bitter joy crusher
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Yes, it's well understood that lactate is fuel. Glucose and glycogen metabolize into pyruvate via a process called oxidative phosphorylation. If there's enough oxygen around, the pyruvate is then metabolized via the "TCA cycle."

When you have enough oxygen, most of the ATP that fuels your muscles is produced by metabolizing pyruvate aerobically in the TCA cycle, which runs about 100 times faster than oxidative phosphorylation.

If there's not enough oxygen, the pyruvate is anaerobically metabolized into lactate. This provides a little energy, but not nearly as much as the aerobic TCA cycle. Cells then secrete lactate into the blood, where it is transported to the liver and heart, which convert it back to pyruvate, which is eventually metabolized aerobically.

The significance of elevated blood lactate is that you don't have enough oxygen to get most of the energy out of your glucose and glycogen, so your muscles are having a hard time getting enough energy to sustain the effort.

The lactate is not the source of the problem, but an indicator of it. As Kolata writes, the problem is lack of oxygen.

Despite what Kolata says, this has been well-known for many years and the metabolic pathways of glucose and ATP have been spelled out in undergraduate biology textbooks for quite a long time.

An excellent description of metabolism in muscles can be found in Bicycling Science (MIT Press, 2004).
 

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Interesting stuff - although it should be mentioned that someone on a different message board noted that Gina Kolata had in the past had a hard time differentiating between myth and fact. So, YMMV...
 

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I thought lactic acid built up in your legs mainly when you were really slowly grinding away and dropping into an easier gear to spin it out was a way to get rid of it, which actually seemed to work for me for some reason.
you're not getting rid of lactic acid by spinning, you're reverting to an aerobic system for locomotion. By using the lower-torque/same-power locomotion, you're not stressing your anaerobic system but using your aerobic system, which doesn't use lactic acid, although neither system is entirely independent. When you are considered to be in your aerobic zone, some of your metabolism is still using your anaerobic system, and when you are anaerobic, full-on tunnel vision anaerobic, you still are using as much aerobic metabolism as you can. Consider the effort required for VO2 maximum efforts -- a lot. It hurts. Lots of lactic acid. At that point, your aerobic system is working as hard as it can, using as much O2 as your body will give it, but it still entails a fair amount of anaerobic metabolism.
I couldn't tell whether you already got this part -- I'm sorry for patronizing, if I am.
 

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So what is the explanation for the burn when you are anaerobic and can no longer put out and crack?

That is missing from their counter.


philippec said:
All you thought you knew about lactic acid (and LT training) might be wrong....

back to the drawing board...or not. read on.

As published by the New York Times:

Lactic Acid Is Not Muscles' Foe, It's Fuel
By GINA KOLATA
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.

....[snip!]

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."
 

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bas said:
So what is the explanation for the burn when you are anaerobic and can no longer put out and crack?

That is missing from their counter.
People with McArdle's Disease lack one of the enzymes in the glycolytic pathway. Consequently they produce little if any lactic acid when exercising and must rely on oxidative metabolism almost exclusively. Yet they experience considerable muscle discomfort. When lactic acid is accumulating any number of other metabolites are also accumulating (inorganic phospate, ADP, calcium, etc.).
 

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I don't think that muscle fatigue and the sensations it causes are very well understood. But one thing that has been established is that it ain't the lactic acid that causes failure. An excessive level seems to correlate with failure, but it pretty clearly doesn't cause it.
That never made sense, when you think about it.
So much of what passes for accepted wisdom in cycledom doesn't much make sense. Lance worked his ass off every winter, and look what happened to him, and Floyd worked hard last winter, and look what is happening to him, and Basso said that he worked hard last winter, and look at him, and the guys from yore who did cyclocross worked their asses off all winter, and you'll still hear coaches say, don't go hard in winter, because you'll ruin your training. Well, you may ruin your mood, but you won't ruin your body.
Jan appears to take the older view pretty seriously, though.
 

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bill said:
So much of what passes for accepted wisdom in cycledom doesn't much make sense.
I think in the case of lactic acid it made a lot of sense in that there was a good correlation with fatigue and a good bit of basic science to support a causal relationship. However, there was always the McArdle's patients to argue against it. As experimental techniques improved it became clear that the correlation between lactic acid accumulation (and the associated acidosis) and fatigue wasn't so tight. There really has been a paradigm shift in the view of the role of lactic acid in exercise metabolism thanks largely to GA Brooks.
 

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TurboTurtle said:
Just because lactate isn't bad does not mean that its build up in the blood is not a good indicator. - TF
Of course with power meters being so readily available these days there is almost no reason for a cyclist/coach to measure any "indicator". Watts tells you pretty much all you need to know regardless of what physiolocially is happening as a consequence of or in order to produce that work.
 

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The article is useless from a training perspective. Is that supposed to mean that we can continue to pedal even when our muscle is so fatigue that you can't produce more power any more??? Is that supposed to mean that we can TT "forever" at vo2max because LT is a fuel now????

Dwayne Barry said:
Of course with power meters being so readily available these days there is almost no reason for a cyclist/coach to measure any "indicator". Watts tells you pretty much all you need to know regardless of what physiolocially is happening as a consequence of or in order to produce that work.
 

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Orbea_Carbon_Force said:
The article is useless from a training perspective. Is that supposed to mean that we can continue to pedal even when our muscle is so fatigue that you can't produce more power any more??? Is that supposed to mean that we can TT "forever" at vo2max because LT is a fuel now????
I don't think it was meant to be a training article but rather an article debunking a commonly held belief related to training and endurance exercise performance.
 

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Awright, maybe that's overstated. Let's just say that the first time I heard the alternative theory -- that it increased endurance rather than defeated it -- it made perfect sense. Why would the body produce this substance to use for extreme effort -- and its role in producing energy has long been understood -- that would cause fatigue?
But you do have to admit that there is a whole lot of other bunk that passes for received wisdom. Sometimes it's close enough to be plausible and even sort of work, just as the Earth being the center of the Universe was close enough for a really, really long time.
 

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philippec said:
All you thought you knew about lactic acid (and LT training) might be wrong....

back to the drawing board...or not. read on.

."
It seems you didn't read the article.:mad2: It clearly states that the accepted training regimens are bang on, and it was just the scientists that misunderstood what the lactic acid was used for.
 

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LyncStar said:
It seems you didn't read the article.:mad2: It clearly states that the accepted training regimens are bang on, and it was just the scientists that misunderstood what the lactic acid was used for.
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.
well, the coaches misunderstood it, too, but their methods for developing lactic acid "tolerance" have turned out to be effective, arguably for the wrong reasons.
 

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surista said:
it should be mentioned that someone on a different message board noted that Gina Kolata had in the past had a hard time differentiating between myth and fact.
Would you like to be a bit more specific?

Kolata has made some bad calls before (such as her plugging Jim Watson's "news" about angiostatin) but for the most part, she's a superb reporter on medical science and you'd be hard pressed to find someone who does the job better.

This article is a dud, and I can guess how it happened. Kolata is an enthusiastic cyclist and has written about bicycling as well as science for the Times. My guess is that she had uncritically accepted a lot of nonsense about lactate in the past (from Bicycling magazine etc.), so when she found out she was wrong, she assumed it was news to scientists as well.

But this dud doesn't mean that she's generally a hack. Everyone has a bad day and on average, Kolata is a damned fine reporter.
 

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I read an article in Men's Fitness about a year ago that said essentially the same thing. It stated that it is commonly believed that lactic acid causes muscle soreness but it they are not sure exactly what causes soreness. One thought was that it was microscopic tears in the muscle fibers.
 

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bill said:
well, the coaches misunderstood it, too, but their methods for developing lactic acid "tolerance" have turned out to be effective, arguably for the wrong reasons.
Who cares? I think most cyclists couldn't give a rat's a$$ about the "whys" of training and just want to make sure that the "hows" they've been told are correct.:p
 
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