Interval training and lactic acid threshold came up in the "coaching" feature on the OLN Paris- Roubaix coverage. Here's a link, and links from this page are good too:

http://sportsmedicine.about.com/cs/exercisephysiology/a/aa091301a.htm

I suppose I've been training around this threshold for years, but we never had a term for it.

I recently (in the last six months) encountered a report (I think it was on the radio) about the misunderstood effects of lactic acid build-up. The long-held assumption was that lactic acid buildup contributes to muscular failure -- that your muscles can't sustain the level of lactic acid that builds up with anaerobic effort, which causes muscular fatigue to failure.
As you soon will see, I remember few salient details, but, anyway, a recent study had suggested that lactic acid buildup may be uncomfortable but that the acid buildup in itself doesn't contribute to muscle failure. If anything, the increased lactic acid concentration was associated with increased endurance. I forget the protocols, but the upshot was that we may need to rethink some of the assumptions about lactic acid. If the study was correct, it wouldn't moot training at threshold, which clearly provides benefits, but it would stop us from thinking that lactic acid causes any damage.

Interval training and lactic acid threshold came up in the "coaching" feature on the OLN Paris- Roubaix coverage. Here's a link, and links from this page are good too:

http://sportsmedicine.about.com/cs/exercisephysiology/a/aa091301a.htm

I suppose I've been training around this threshold for years, but we never had a term for it.

Carmichael is a hack...

Carmichael is a hack...

OK, show me something better, more informed, more authoratative.

-- Easy to throw stones, much more constructive to build with them.

OK, show me something better, more informed, more authoratative.

-- Easy to throw stones, much more constructive to build with them.
Off the top of my head, http://www.cyclingpeakssoftware.com/levels.html for starters, there's a lot more especially work by Burke, Coyle, or Jeukendrup.

OK, Coggan's site is authoratative, but I get really alienated when I search a site for information and discover that it's little more than an ad and an attempt to sell me something.

"Lactate threshold" searched on Google gets about 110,000 links. Some are books, products, sales pitches. Some are informational sites. You'll have to excuse me if I prefer the informational sites. I'm just an old academic who still thinks the purpose of the internet is to share data and information rather than its being a portal to a more profitable sales margin.

LT is a new concept for me. I've seen it posted, seen it used in discussions. But I'd not seen it defined nor an explanation as to how one determines an LT.

But I understand the concept now, and can find one.

OK, Coggan's site is authoratative, but I get really alienated when I search a site for information and discover that it's little more than an ad and an attempt to sell me something.

"Lactate threshold" searched on Google gets about 110,000 links. Some are books, products, sales pitches. Some are informational sites. You'll have to excuse me if I prefer the informational sites. I'm just an old academic who still thinks the purpose of the internet is to share data and information rather than its being a portal to a more profitable sales margin.

LT is a new concept for me. I've seen it posted, seen it used in discussions. But I'd not seen it defined nor an explanation as to how one determines an LT.

But I understand the concept now, and can find one.

And CTS is not selling something? Of course they are, they're selling their services.

From what I hear from a few different folks on the inside of CTS, is that he doesn't really do much at all of the coaching, most of the other coaches on staff create the workouts, do the scientific legwork, and such. When I said Carmichael is a hack, I meant, him. His staff is top notch on the other hand, and CTS is great. He... Eh, not so much.

It basically was a problem of seeing a correlation between muscle fatigue (an inability to maintain a given force or power output) and lactic acid accumulation and assuming there was a causal relationship. In fairness there was some single cell work that also suggested lactic acid caused fatigue.

Then evidence to the contrary came out, the early single cell work was done at low non-physiologic temps, when repeated at physiologic temps there was no fatiguing effect of adding lactic acid and in fact, you can see a reversal by adding lactic acid. Once magnetic resonsance spectroscopy became available, you could actually measure the pH of muscle and calculate the intramuscular lactic acid levels rather than relying on blood lactic acid levels. Using this technique the correlation between lactic acid and fatigue breaks down.

So lactic acid per se has been largely dismissed as a causitive agent in fatigue. This has always been hinted at by people with McArdle's disease that lack an enzyme in the glycolytic pathway and therefore don't produce lactic acid, yet show an extreme intolerance to exercise and rapidly fatigue.

George Brooks has done work for the last couple of decades that has largely shifted the paradigm of lactic acid as bad end product of glycolysis leading to fatigue to lactic acid as the body's way of transporting the products of glycolysis from areas of low oxidative capacity (like type II fibers) to areas of high oxidative capacity (Type I fibers, heart, liver) where more ATP can be produced.

Accumulation of blood lactate acid is merely an indication that the muscular work you are performing is out-stripping your body's oxidative capacity, hence there is no more tissue to oxidize the lactic acid, but there are certainly other things happening in the muscle at this point that could be causing fatigue and are just much harder to measure. Factors such as inorganic phosphate accumulation and disruption of the normal calcium handling processes that regulate muscle contraction.

whoaa.
say amen, my brother.
cool, man. I got it. Sort of. Enough of it, anyway.
I am gathering that nothing you're saying really changes the equation in terms of the value of training at threshold -- as a measure of where the muscles fail, it is what it is -- but it debunks the harmful effect of lactic acid mantra which we see so darn often. Like so much conventional wisdom, like the correlation between unguarded piles of corn and rats born in them or the rooster causing the sun to rise, it's useful enough to a point, but it isn't right, and we shouldn't extrapolate beyond what we know. Cycling is particularly this way, I think (LSD, KOPS, anyone? should I go on?).

Off the top of my head, http://www.cyclingpeakssoftware.com/levels.html for starters, there's a lot more especially work by Burke, Coyle, or Jeukendrup.
I wouldn't cite Burke as evidence that Carmichael's a hack. Burke clearly thought very highly of Carmichael.

Look up Chris Carmichael in the index of Burke's Serious Cycling. There are quite a few entries where Burke cites Carmichael's coaching advice as authoritative. Burke also invited Carmichael to write the foreward as well as a two-page bit on using power meters in training. This doesn't prove that Carmichael is good, but it does prove that Burke thought he was.

(that were written recently.) Lactic Acid is not what causes muscle damage. I've read that the build up can actually help the muscles produce more energy or eliminate fatigue. However, it is a good indicator that the muscles and body have gone into the anerobic zone. There are a lot of other complex reactions occuring once you are in the anerobic zones that cause muscle damage, fatigue, and if in the zone too long the body will start converting muscle tissues to energy on a rather large scale.

The important point is Lactic Threshold is still a very important transission point to be aware of in training. If you are really hung up on this, use the term Maximum Sustainable Workload (for most people very close to the same HR as LT).

The bottom line is when you feel the burn, muscle damage is probably occuring. Not due the Lactic Acid (it is a side effect) but due to the more complex things going on in the muscles while they are trying to create energy without enough oxygen. This damage is a good thing if you train correctly and don't over do it for too long. During the rebuilding process the body often over adapts to the stress and this makes you stronger and improves your anerobic threshold and your ability to opertate anerobically (if you rest properly between these hard efforts)


It basically was a problem of seeing a correlation between muscle fatigue (an inability to maintain a given force or power output) and lactic acid accumulation and assuming there was a causal relationship. In fairness there was some single cell work that also suggested lactic acid caused fatigue.

Then evidence to the contrary came out, the early single cell work was done at low non-physiologic temps, when repeated at physiologic temps there was no fatiguing effect of adding lactic acid and in fact, you can see a reversal by adding lactic acid. Once magnetic resonsance spectroscopy became available, you could actually measure the pH of muscle and calculate the intramuscular lactic acid levels rather than relying on blood lactic acid levels. Using this technique the correlation between lactic acid and fatigue breaks down.

So lactic acid per se has been largely dismissed as a causitive agent in fatigue. This has always been hinted at by people with McArdle's disease that lack an enzyme in the glycolytic pathway and therefore don't produce lactic acid, yet show an extreme intolerance to exercise and rapidly fatigue.

George Brooks has done work for the last couple of decades that has largely shifted the paradigm of lactic acid as bad end product of glycolysis leading to fatigue to lactic acid as the body's way of transporting the products of glycolysis from areas of low oxidative capacity (like type II fibers) to areas of high oxidative capacity (Type I fibers, heart, liver) where more ATP can be produced.

Accumulation of blood lactate acid is merely an indication that the muscular work you are performing is out-stripping your body's oxidative capacity, hence there is no more tissue to oxidize the lactic acid, but there are certainly other things happening in the muscle at this point that could be causing fatigue and are just much harder to measure. Factors such as inorganic phosphate accumulation and disruption of the normal calcium handling processes that regulate muscle contraction.

I wouldn't cite Burke as evidence that Carmichael's a hack. Burke clearly thought very highly of Carmichael.

Look up Chris Carmichael in the index of Burke's Serious Cycling. There are quite a few entries where Burke cites Carmichael's coaching advice as authoritative. Burke also invited Carmichael to write the foreward as well as a two-page bit on using power meters in training. This doesn't prove that Carmichael is good, but it does prove that Burke thought he was.
You might try to actually read and comprehend posts before commenting on them. Nowhere did I say Charmichael is a hack or comment on him in any way. There was a request for more authoritative publications than the one originally referenced and I believe I provided a lead to several.

(that were written recently.) Lactic Acid is not what causes muscle damage. I've read that the build up can actually help the muscles produce more energy or eliminate fatigue. However, it is a good indicator that the muscles and body have gone into the anerobic zone. There are a lot of other complex reactions occuring once you are in the anerobic zones that cause muscle damage, fatigue, and if in the zone too long the body will start converting muscle tissues to energy on a rather large scale.

The important point is Lactic Threshold is still a very important transission point to be aware of in training. If you are really hung up on this, use the term Maximum Sustainable Workload (for most people very close to the same HR as LT).

The bottom line is when you feel the burn, muscle damage is probably occuring. Not due the Lactic Acid (it is a side effect) but due to the more complex things going on in the muscles while they are trying to create energy without enough oxygen. This damage is a good thing if you train correctly and don't over do it for too long. During the rebuilding process the body often over adapts to the stress and this makes you stronger and improves your anerobic threshold and your ability to opertate anerobically (if you rest properly between these hard efforts)

My understanding is that as lactic acid accumulates you are also getting a large amount of Hydrogen ions flying around the muscle. This is what an acid does by definition, but it is still incorrect to say the acid is causing the damage. The resulting hydrogen ions are what destroy the muscle. My gut tells me I read this in Dave Morris' book, Performance Cycling, but I don't have a source handy,

Silas

LT is a new concept for me. I've seen it posted, seen it used in discussions. But I'd not seen it defined nor an explanation as to how one determines an LT.



You still haven't, the term LT has been widely misused to mean any number of things. The original ex.phys. definition is along the lines of a 1mmol rise above baseline during a graded/step test. This is now commonly refered to as OBLA or onset of blood lactate. many coaches have used LT to mean either a 4mmol/L blood lactate concentration.

Since both of these definitions require lab or psuedo-lab settings various feild tests have been proposed to determine LT. (30min TT, 60min TT or correlation with VT)

There are now a plethora of terms to try and define a sustainable aerobic state with the current favorite seeming to be MLSS or "steady state", the intensity at which lactate does not show increasing accumulation. This definition does have some sort of time dependancy though

"Lactic Acid is not what causes muscle damage. I've read that the build up can actually help the muscles produce more energy or eliminate fatigue. However, it is a good indicator that the muscles and body have gone into the anerobic zone. There are a lot of other complex reactions occuring once you are in the anerobic zones that cause muscle damage, fatigue, and if in the zone too long the body will start converting muscle tissues to energy on a rather large scale."

I think you're confounding a number of issues here. My comments really pertain only to muscle fatigue, which can certainly occur do to muscle damage, but I think in most cycling situations this would not be the couse of fatigue. Primarily because cycling involves exclusively concentric contractions (force is produced as the muscles shortens) rather than eccentric contractions (force produced as the muscles lengthened). This is, in part, why guys can ride 5 or 6 hours a day for 3 weeks with daily high-intensity efforts and not implode, where as marathon running, which involves eccentric contractions of the quads, is done only occassionally and produces significant muscle damage.

"The important point is Lactic Threshold is still a very important transission point to be aware of in training. If you are really hung up on this, use the term Maximum Sustainable Workload (for most people very close to the same HR as LT)."

I would argue not really. Power is what matters, using your sustainable power output to determine work zones seems to make the most sense to me, regardless of what is going on physiologically.

"The bottom line is when you feel the burn, muscle damage is probably occuring. Not due the Lactic Acid (it is a side effect) but due to the more complex things going on in the muscles while they are trying to create energy without enough oxygen. This damage is a good thing if you train correctly and don't over do it for too long. During the rebuilding process the body often over adapts to the stress and this makes you stronger and improves your anerobic threshold and your ability to opertate anerobically (if you rest properly between these hard efforts)"

I'm not sure that is entirely true. Certainly the main culprit in muscle damage is high-force eccentric contractions, which don't occur in cycling. Does acidosis cause muscle damage of another sort? I don't think there is any answer to that. Certainly, acidosis is not good for cells and can damage things, but I'm not sure if the acidosis that occurs during intense endurance exercise is sufficient to actually cause damage. Again, I'm not sure the adaptations that occur with endurance exercise (fiber-type shift toward type I fibers, increase mitochondrial density and enzyme levels, increased capillirization of the muscle, increased stroke volume of the heart) are stimulated by "break down" and rebuilding of the muscle per se.

I agree that Charmichael isn't a hack. He is a very smart person who uses other peoples ideas to promote himself. I have my doubts that he has ever come up with an original idea of his own.

My understanding is that as lactic acid accumulates you are also getting a large amount of Hydrogen ions flying around the muscle. This is what an acid does by definition, but it is still incorrect to say the acid is causing the damage. The resulting hydrogen ions are what destroy the muscle. My gut tells me I read this in Dave Morris' book, Performance Cycling, but I don't have a source handy,

Silas

I'm fairly certain, there is no "destroying" of muscle going on during high intensity efforts resulting in acidosis in the muscle. At least I've never read or seen anything about it. OTOH, it is quite easy to "destroy" muscle fibers by subjecting them to high forces as they lengthen. This is what produces delayed-onset muscle soreness (DOMS) following weightlifting or hiking downhill with a backback. In animal models, you can quite literally see the damaged fibers with microscopy. The fact that DOMS isn't typically associated with cycling suggests to me that it is unlikely to produce physical damage to the muscle.

"Lactic Acid is not what causes muscle damage. I've read that the build up can actually help the muscles produce more energy or eliminate fatigue. However, it is a good indicator that the muscles and body have gone into the anerobic zone. There are a lot of other complex reactions occuring once you are in the anerobic zones that cause muscle damage, fatigue, and if in the zone too long the body will start converting muscle tissues to energy on a rather large scale."

I think you're confounding a number of issues here. My comments really pertain only to muscle fatigue, which can certainly occur do to muscle damage, but I think in most cycling situations this would not be the couse of fatigue. Primarily because cycling involves exclusively concentric contractions (force is produced as the muscles shortens) rather than eccentric contractions (force produced as the muscles lengthened). This is, in part, why guys can ride 5 or 6 hours a day for 3 weeks with daily high-intensity efforts and not implode, where as marathon running, which involves eccentric contractions of the quads, is done only occassionally and produces significant muscle damage.



But these cyclist are not riding above LT or Max Sustainable Workload or what ever you want to call an anerobic efforts for 5-6 hours a day for 3 weeks straight. Most of that work is below LT and in an Aerobic state. I'm only capable of staying in the anerobic state for a couple of minutes at most. A really good cyclist can stay there for about 5 minutes the elites a little more.

It is a very bad idea to be doing anerobic intervals every day because the body does not have to to rebuild and repair the damage caused by such workouts and this can do more harm than good. My points was that at above LT damage occurs, not directly due to Lactic Acid but it occurs due to other bits of chemistry.

It is a very bad idea to be doing anerobic intervals every day because the body does not have to to rebuild and repair the damage caused by such workouts and this can do more harm than good. My points was that at above LT damage occurs, not directly due to Lactic Acid but it occurs due to other bits of chemistry.

My point was that I'm far from certain that that is true and if fact, if I had to put money on it, I would bet it is not the case. The literature is full of evidence for muscle damage from high force contraction, especially eccentric ones. I'm simply saying I can't recall ever seeing anything about supra-LT work actually causing damage to the cells. It certainly is a commonly held cycling "truism" but that doesn't mean it's an actual reflection of reality.

I'm fairly certain, there is no "destroying" of muscle going on during high intensity efforts resulting in acidosis in the muscle. At least I've never read or seen anything about it. OTOH, it is quite easy to "destroy" muscle fibers by subjecting them to high forces as they lengthen. This is what produces delayed-onset muscle soreness (DOMS) following weightlifting or hiking downhill with a backback. In animal models, you can quite literally see the damaged fibers with microscopy. The fact that DOMS isn't typically associated with cycling suggests to me that it is unlikely to produce physical damage to the muscle.


Dwayne, you are exactly right. When I got home today I checked out my book, and here's the quote:

"However, during intense excercise when lactic acid (and hydrogen ion) production is excessive, hydrogen ions accumulate in the muscle, which inhibits glycolysis, hinders energy production and interferes with the mechanical aspects of muscle contraction. In short, the accumulation of hydrogen ions can stop an athlete from performing all but the lightest of exercise." Performance Cycling, pg.20

So, no mention of damage at all, but somehow that concept was stuck in my head. The real deal is that lactic acid buildup continues until it reaches a point of no return and forces the body to recover. I'm sure we've all had this feeling upon being dropped just before the top of a hill.

Silas

"However, during intense excercise when lactic acid (and hydrogen ion) production is excessive, hydrogen ions accumulate in the muscle, which inhibits glycolysis, hinders energy production and interferes with the mechanical aspects of muscle contraction. In short, the accumulation of hydrogen ions can stop an athlete from performing all but the lightest of exercise." Performance Cycling, pg.20

That is certainly one possibility, but it undoubtably isn't the only one. For example if you start a full out sprint from rest you'll use the phoshocreatine (PCr) stores to rapidly replace the ATP you're consuming. Well your power will start dropping in a matter of seconds, but the breakdown of PCr and generation of ATP actually consumes H+ ions (i.e. the muslce is becoming more alkaline rather than acidic) so fatigue is occuring while the muslce is actually becoming less acidic, hard to say acidosis is the cause of fatigue in this instance. At the other end of the spectrum when you stop exercising, PCr is replenished and this produces H+ ions so the muscle continues to become more acidic for a time, yet force/power starts to recover quite rapidly. So here again you have a breakdown of the association of fatigue & acidosis.


"The real deal is that lactic acid buildup continues until it reaches a point of no return and forces the body to recover. I'm sure we've all had this feeling upon being dropped just before the top of a hill."

Let's be clear here. It's not the lactic acid per se, it is the H+ ions which cause a drop in the pH of the cells (i.e. acidosis) and are thought to contribute to fatigue in some instances. I think it's been pretty well established that the lactic acid itself isn't a player. And just to complicate matters, not that I would pretend to understand it, but apparently a biochemical arguement can be made that the source of the excess H+ ions during intense exercise isn't from the producition of lactate but rather from the breakdown of ATP itself.