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Nwlifter

Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.


https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.



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Average Al

Bill Sekerak wrote:



" If you like exercise you're probably doing it wrong. "- Arthur Jones




Possibly. But I am more interested in what works for me practically, than in some theoretical ideal that is extraordinarily difficult to put into practice, or sustain for lifetime.

Jones said something to the effect that properly performed strength training eliminated the need for cardiovascular conditioning. But what did he mean by the phrase "properly performed". Something like the West Point experiment? Maybe that worked for highly motivated 20 year old cadets being driven by a drill Sargent/trainer for a 12 week study? Anybody really going to be doing that for the rest of their lives? Jones certainly didn't follow his own advice, as I understand that he would not train at all for long stretches of time.

So how many HIT studios preach that HIT gives all the cardiovascular conditioning their clients need, and then routinely fail to come close to the level of intensity required to actually deliver the promised results?

Might not those clients be better served by doing something less intense and longer in duration, where the level of compliance is higher?
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Average Al

Bill Sekerak wrote:

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.


Yah... At one point, the thinking seemed to be that some Type II fibers were able to engage in a sort of type shifting, taking on characteristics that were better for strength or endurance, depending on how you trained. These shifts now are being attributed the existence of these hybrid fibers.

What is most interesting about this is the degree of plasticity that they seem to be finding, and how rapidly these fibers can adjust to training stress.

I wonder if this will change the interpretation of other observations about strength training:

- It seems pretty well established that explosiveness is more a matter of nature than nurture. This used to be explained as having to do with the amount of FT fiber you were born with. But maybe it has more to do with the kind of nervous system you were born with. Maybe people with more efficient or powerful nervous systems can do a better job of turning hybrids into fast twitch?

- I also wonder about the observation that, even among people who continue to train, there is a decline in the amount of FT fiber with age? Does the fact that we all have lots of hybrid fibers lend credence to the theory that the decline in explosiveness is due to effects of age on the nervous system, such that we can no longer turn hybrids into fast twitch?

- Other limits on muscle size still exist. Galpin talks about how the density of nuclei sites within a muscle affect how large it can grow, with higher density being better for growth. This could still be influenced by genetics. And guess what: taking steroids can increase the density, possibly in a permanent manner.
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Average Al

Bill Sekerak wrote:

I won't belabor the point but there are scientific absolutes that will never change.
As Aristotle stated A = A. Uranium decays at a known rate under certain circumstances and at another under different circumstances.
The square root of 144 is 12. Etc.etc
I know that many Universities have professors who teach you can never know anything as everything is always in flux. However that's total BS. They don't even recognize that the above statement is presented as an absolute thus it negates itself.


It isn't worth arguing about, but I am pretty sure that most professional scientists do not accept the notion of 'scientific absolutes'.

A=A is a logical proposition, not science.

That the square root of 144 is 12 is math, which isn't science.

The consistency of certain physical constants, like the speed of light, is based entirely on observation, not theory. The speed of light will continued to be viewed as something fixed until someone makes a valid measurement that shows something different.
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epdavis7

Average Al wrote:
Bill Sekerak wrote:

I won't belabor the point but there are scientific absolutes that will never change.
As Aristotle stated A = A. Uranium decays at a known rate under certain circumstances and at another under different circumstances.
The square root of 144 is 12. Etc.etc
I know that many Universities have professors who teach you can never know anything as everything is always in flux. However that's total BS. They don't even recognize that the above statement is presented as an absolute thus it negates itself.


It isn't worth arguing about, but I am pretty sure that most professional scientists do not accept the notion of 'scientific absolutes'.

A=A is a logical proposition, not science.

That the square root of 144 is 12 is math, which isn't science.

The consistency of certain physical constants, like the speed of light, is based entirely on observation, not theory. The speed of light will continued to be viewed as something fixed until someone makes a valid measurement that shows something different.


Is this within the realm of topic? When in the military we did primarily short runs that we were timed on. I got fairly good at running them quickly for someone of my size. Since I retired from the military I have been doing 10+ mile races. I can no longer run at the same pace I used to (some can be attributed to aging), but can run for much longer distances. Conversion from fast twitch to slow twitch?
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oldbutsteady

Bill,

Please get over your man crush with Jones, it is wearing a bit thin.

Any statement that begins with "I think.." is subjective and is an educated guess at best but you seem to take those as fact. I don't think most people are interested in what Jones did or didn't say or even who he is for that matter.

Everyone here has read his stuff ad infinitum and nothing new will be or can be learned from any of his statements.

Lastly, much of what he regurgitated was well known long before he uttered it but you don't seem to realize or care about that small fact.

OBS


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AndyMitch

I?d like to re-visit the chicken or the egg argument
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Nwlifter

AndyMitch wrote:
I?d like to re-visit the chicken or the egg argument


Me too lol
I posit that the chicken had to come first, an egg can't hatch without also a chicken to sit on it, but a chicken can exist without an egg.....
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entsminger

Virginia, USA

Bill,

Please get over your man crush with Jones, it is wearing a bit thin.

==Scott==
Ha ha !
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S.M.Punisher

Nwlifter wrote:
I posit that the chicken had to come first, an egg can't hatch without also a chicken to sit on it, but a chicken can exist without an egg.....


I'm going with the egg. For a chicken to be a chicken, one might say that by nature it had to have come from an egg; but an egg could have been an egg regardless of whether it had come from a chicken.

You could say that for it to have been an egg capable of a chicken, it had to have come from one; but I say that for the first time the egg had been capable of anything, why not the chicken?
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Nwlifter

S.M.Punisher wrote:
Nwlifter wrote:
I posit that the chicken had to come first, an egg can't hatch without also a chicken to sit on it, but a chicken can exist without an egg.....

I'm going with the egg. For a chicken to be a chicken, one might say that by nature it had to have come from an egg; but an egg could have been an egg regardless of whether it had come from a chicken.

You could say that for it to have been an egg capable of a chicken, it had to have come from one; but I say that for the first time the egg had been capable of anything, why not the chicken?


So who laid the egg? ;)
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oldbutsteady

I think Grant came first but I could be wrong...

OBS
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BorisV

Maryland, USA

Nwlifter wrote:
Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.





The idea of something having a very distinctive nature and characteristics (ST fibers) converting into another thing which has a completely different nature and characteristics (FT fibers) doesn't look very plausible to me. I would say that anaerobic training may wake up some FT fibers which were previously dormant, but I don't buy into the idea of conversion of ST fibers into FT fibers. For the same reason muscles can't be converted into fat and vice versa. From the practical viewpoint, how many of you have checked their fiber type and did it several times during your training carrier? Presuming you are engaged in anaerobic training, did you see any significant changes in your fiber types? I didn't. Coincidentally, I tested my fiber type just yesterday, and previously I tested them may be 10 years ago. Nothing has changed, and all my fiber types are predominantly ST, although I almost exclusively train anaerobically.
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Nwlifter

BorisV wrote:
Nwlifter wrote:
Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.





The idea of something having a very distinctive nature and characteristics (ST fibers) converting into another thing which has a completely different nature and characteristics (FT fibers) doesn't look very plausible to me. I would say that anaerobic training may wake up some FT fibers which were previously dormant, but I don't buy into the idea of conversion of ST fibers into FT fibers. For the same reason muscles can't be converted into fat and vice versa. From the practical viewpoint, how many of you have checked their fiber type and did it several times during your training carrier? Presuming you are engaged in anaerobic training, did you see any significant changes in your fiber types? I didn't. Coincidentally, I tested my fiber type just yesterday, and previously I tested them may be 10 years ago. Nothing has changed, and all my fiber types are predominantly ST, although I almost exclusively train anaerobically.


There aren't any 'dormant' fibers though, no such thing. All fibers are alive and innervated by nerves.

But myosin heavy chain variations are nothing like 'fat to muscle', all fibers are capable of expressing variations in how they express, the neural inputs determine (signal) how they should 'express'. An ST and and FT fiber are the same, one just has more of something things and less of another and visa versa.
they have even done tests where they moved the nerve from one MU to another and the fibers then slowly changed to match that neural input.
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Nwlifter

BorisV wrote:
Nwlifter wrote:
Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.





The idea of something having a very distinctive nature and characteristics (ST fibers) converting into another thing which has a completely different nature and characteristics (FT fibers) doesn't look very plausible to me. I would say that anaerobic training may wake up some FT fibers which were previously dormant, but I don't buy into the idea of conversion of ST fibers into FT fibers. For the same reason muscles can't be converted into fat and vice versa. From the practical viewpoint, how many of you have checked their fiber type and did it several times during your training carrier? Presuming you are engaged in anaerobic training, did you see any significant changes in your fiber types? I didn't. Coincidentally, I tested my fiber type just yesterday, and previously I tested them may be 10 years ago. Nothing has changed, and all my fiber types are predominantly ST, although I almost exclusively train anaerobically.


missed one point...
so you had full body muscle biopsies? That's the only way to check fiber type.
That 'how many reps with an RM' is more than inaccurate... SO many other things affect that more than 'fiber type'. Neural efficiency, practice, glycogen content, capillary density, mitochondrial density, pain tolerance, neural inhibitions,... etc.
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oldbutsteady

Boris,

If you didn't change your training routine why would you think the muscle fibers would change?

OBS
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BorisV

Maryland, USA

Nwlifter wrote:
BorisV wrote:
Nwlifter wrote:
Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.





The idea of something having a very distinctive nature and characteristics (ST fibers) converting into another thing which has a completely different nature and characteristics (FT fibers) doesn't look very plausible to me. I would say that anaerobic training may wake up some FT fibers which were previously dormant, but I don't buy into the idea of conversion of ST fibers into FT fibers. For the same reason muscles can't be converted into fat and vice versa. From the practical viewpoint, how many of you have checked their fiber type and did it several times during your training carrier? Presuming you are engaged in anaerobic training, did you see any significant changes in your fiber types? I didn't. Coincidentally, I tested my fiber type just yesterday, and previously I tested them may be 10 years ago. Nothing has changed, and all my fiber types are predominantly ST, although I almost exclusively train anaerobically.

missed one point...
so you had full body muscle biopsies? That's the only way to check fiber type.
That 'how many reps with an RM' is more than inaccurate... SO many other things affect that more than 'fiber type'. Neural efficiency, practice, glycogen content, capillary density, mitochondrial density, pain tolerance, neural inhibitions,... etc.


I don't think one need to have a full body muscle biopsy to evaluate predominant fiber type in main muscle groups. I used both tests suggested by IART (both 1RM method and based on TUT), and both gave the same results. Moreover, with my 30 years experience of training it would be a crime not to see certain patterns in how my muscles react to different loads, TUTs, rep scheme, cadence, density, set scheme, intensity, frequency, volume and overall demands. It certainly didn't work for me - I didn't get more FT fibers as a result of my training (and I used different methods of training during my 30 years in the iron game) and I haven't seen a single person with preponderance of ST fibers who, as a result of anaerobic training along, converted his/her body into a muscle machine with predominantly FT fibers and who, following a proper training, got a tremendous muscle growth (since FT fibers are sensitive to stimulation and responsible for most muscle size and a maximum strength potential). Of course, setting aside guys on steroids and other artificial compounds. I witnessed the effect of trenbolone on an average guy.
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BorisV

Maryland, USA

oldbutsteady wrote:
Boris,

If you didn't change your training routine why would you think the muscle fibers would change?

OBS


OBS, why do you think I didn't and do not change my routines regularly? In my 30 years of training I tried many methods, and for the last 5 years I have been changing my routines every other week. There could be a change in the set/rep/cadence and/or frequency/volume/intensity/density and/or exercise choice and/or number of body parts per workout, or different methods (too many to mention here). I become psychologically and physically accustomed to any routine very shortly - even repeating the same routine same or next week doesn't produce the same effect on the muscle fullness and pump. I moved from pure HIT training and do it only sporadically as a matter of variation.
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oldbutsteady

Boris,

I stand corrected I thought you said you're training was mostly aerobic, I misread.

My apologies

OBS
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BorisV

Maryland, USA

Nwlifter wrote:
BorisV wrote:
Nwlifter wrote:
Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.





The idea of something having a very distinctive nature and characteristics (ST fibers) converting into another thing which has a completely different nature and characteristics (FT fibers) doesn't look very plausible to me. I would say that anaerobic training may wake up some FT fibers which were previously dormant, but I don't buy into the idea of conversion of ST fibers into FT fibers. For the same reason muscles can't be converted into fat and vice versa. From the practical viewpoint, how many of you have checked their fiber type and did it several times during your training carrier? Presuming you are engaged in anaerobic training, did you see any significant changes in your fiber types? I didn't. Coincidentally, I tested my fiber type just yesterday, and previously I tested them may be 10 years ago. Nothing has changed, and all my fiber types are predominantly ST, although I almost exclusively train anaerobically.

There aren't any 'dormant' fibers though, no such thing. All fibers are alive and innervated by nerves.

But myosin heavy chain variations are nothing like 'fat to muscle', all fibers are capable of expressing variations in how they express, the neural inputs determine (signal) how they should 'express'. An ST and and FT fiber are the same, one just has more of something things and less of another and visa versa.
they have even done tests where they moved the nerve from one MU to another and the fibers then slowly changed to match that neural input.


By "dormant" I meant the cells and fibers that are not used even in high-intensity efforts, like "satellite" cells. Hardly the body will use all of the available fibers - makes no sense from the survival standpoint. So all the time there will be a certain reserve.
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Nwlifter

Average Al wrote:
Bill Sekerak wrote:

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

Yah... At one point, the thinking seemed to be that some Type II fibers were able to engage in a sort of type shifting, taking on characteristics that were better for strength or endurance, depending on how you trained. These shifts now are being attributed the existence of these hybrid fibers.

What is most interesting about this is the degree of plasticity that they seem to be finding, and how rapidly these fibers can adjust to training stress.

I wonder if this will change the interpretation of other observations about strength training:

- It seems pretty well established that explosiveness is more a matter of nature than nurture. This used to be explained as having to do with the amount of FT fiber you were born with. But maybe it has more to do with the kind of nervous system you were born with. Maybe people with more efficient or powerful nervous systems can do a better job of turning hybrids into fast twitch?

- I also wonder about the observation that, even among people who continue to train, there is a decline in the amount of FT fiber with age? Does the fact that we all have lots of hybrid fibers lend credence to the theory that the decline in explosiveness is due to effects of age on the nervous system, such that we can no longer turn hybrids into fast twitch?

- Other limits on muscle size still exist. Galpin talks about how the density of nuclei sites within a muscle affect how large it can grow, with higher density being better for growth. This could still be influenced by genetics. And guess what: taking steroids can increase the density, possibly in a permanent manner.


Training also increase myo-nuclei number, for some lucky people, their satellite cells donate like mad, for others, they don't nearly as much.
Each nuclei is a 'protein factory', so it makes sense, the number you have determines cell size.
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Nwlifter

BorisV wrote:
Nwlifter wrote:
BorisV wrote:
Nwlifter wrote:
Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.





The idea of something having a very distinctive nature and characteristics (ST fibers) converting into another thing which has a completely different nature and characteristics (FT fibers) doesn't look very plausible to me. I would say that anaerobic training may wake up some FT fibers which were previously dormant, but I don't buy into the idea of conversion of ST fibers into FT fibers. For the same reason muscles can't be converted into fat and vice versa. From the practical viewpoint, how many of you have checked their fiber type and did it several times during your training carrier? Presuming you are engaged in anaerobic training, did you see any significant changes in your fiber types? I didn't. Coincidentally, I tested my fiber type just yesterday, and previously I tested them may be 10 years ago. Nothing has changed, and all my fiber types are predominantly ST, although I almost exclusively train anaerobically.

missed one point...
so you had full body muscle biopsies? That's the only way to check fiber type.
That 'how many reps with an RM' is more than inaccurate... SO many other things affect that more than 'fiber type'. Neural efficiency, practice, glycogen content, capillary density, mitochondrial density, pain tolerance, neural inhibitions,... etc.

I don't think one need to have a full body muscle biopsy to evaluate predominant fiber type in main muscle groups. I used both tests suggested by IART (both 1RM method and based on TUT), and both gave the same results. Moreover, with my 30 years experience of training it would be a crime not to see certain patterns in how my muscles react to different loads, TUTs, rep scheme, cadence, density, set scheme, intensity, frequency, volume and overall demands. It certainly didn't work for me - I didn't get more FT fibers as a result of my training (and I used different methods of training during my 30 years in the iron game) and I haven't seen a single person with preponderance of ST fibers who, as a result of anaerobic training along, converted his/her body into a muscle machine with predominantly FT fibers and who, following a proper training, got a tremendous muscle growth (since FT fibers are sensitive to stimulation and responsible for most muscle size and a maximum strength potential). Of course, setting aside guys on steroids and other artificial compounds. I witnessed the effect of trenbolone on an average guy.


Actually one would need massive biospies to 'see' and know actual fiber type.

but those kinds of tests are very inaccurate. Too many other factors influence 'reps with some RM' .

then knowing our fibers do alter MHC expression with training, it's really all invalid.

It's also though not so much about FT fibers, they have biopsied pro bodybuilders, they ST fibers are pretty big too and just as responsible for their size as their FT fibers.
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BorisV

Maryland, USA

Nwlifter wrote:
BorisV wrote:
Nwlifter wrote:
BorisV wrote:
Nwlifter wrote:
Bill Sekerak wrote:
Average Al wrote:
I know that science oriented threads get a mixed reception here. Never-the-less, I saw one that seems worthy of mention, should your interests lie in that direction.

It can be found at the Men's Health web site, under the title "How Scientists Use Your Muscles to Predict Your Mortality". It is written by Lou Schuler, based on the work of Andy Galpin, who appears to be one of the current leading experts on muscle fiber characteristics.

The subject of the article is broader than the title might imply. He talks a lot about the latest thinking on muscle fiber type, which is now viewed as much more complex (6 fiber classification, instead of the old I, IIA, and IIX or IIB).

It seems we all have a high percentage of what are called Hybrid Fibers, things which have mixed characteristics. So there are I/IIa fibers, and IIa/IIx fibers and even I/IIa/IIx fibers. What is interesting is that these hybrid fibers seem to be able to shift type according to how you train. So a hybrid I/IIx will shift to type I if you do a lot of endurance work. And IIa/IIx will shift toward IIx if you do a lot of fast explosive lifting.

Galpin has a web site which includes a detailed article about the history and evolution of thinking about fiber classification, along with what he thinks we do and don't know about this area.

Highly recommended.

Yeah, I wasn't aware of the new " subdivisions " but I've known about changing muscle fiber type or at least changes in function for a long time.
I discussed this with Arthur in 1995.
I came to the conclusion,from reading a ton of MedX research papers published and unpublished, that it was possible to train predominantly fast twitch muscle type as you would train predominantly slow twitch fiber and " turn " it into fiber type with slow twitch characterizations but not visa versa.
If the study you reference indicates that predominantly slow twitch fiber type could be changed into predominantly fast twitch fiber that would be news but I would be very skeptical.

https://renaissanceperiodizati...

"An epic study the very next year saw the ST fibers convert to FT following 6 weeks of ?anaerobic training?, and revert right back to ST after the training then changed to aerobic (19)."

Jansson E, Sjodin B, Tesch P. Changes in muscle fibre type distribution in man after physical training. A sign of fibre type transformation Acta Physiol Scand. 1978;104(2):235-7.





The idea of something having a very distinctive nature and characteristics (ST fibers) converting into another thing which has a completely different nature and characteristics (FT fibers) doesn't look very plausible to me. I would say that anaerobic training may wake up some FT fibers which were previously dormant, but I don't buy into the idea of conversion of ST fibers into FT fibers. For the same reason muscles can't be converted into fat and vice versa. From the practical viewpoint, how many of you have checked their fiber type and did it several times during your training carrier? Presuming you are engaged in anaerobic training, did you see any significant changes in your fiber types? I didn't. Coincidentally, I tested my fiber type just yesterday, and previously I tested them may be 10 years ago. Nothing has changed, and all my fiber types are predominantly ST, although I almost exclusively train anaerobically.

missed one point...
so you had full body muscle biopsies? That's the only way to check fiber type.
That 'how many reps with an RM' is more than inaccurate... SO many other things affect that more than 'fiber type'. Neural efficiency, practice, glycogen content, capillary density, mitochondrial density, pain tolerance, neural inhibitions,... etc.

I don't think one need to have a full body muscle biopsy to evaluate predominant fiber type in main muscle groups. I used both tests suggested by IART (both 1RM method and based on TUT), and both gave the same results. Moreover, with my 30 years experience of training it would be a crime not to see certain patterns in how my muscles react to different loads, TUTs, rep scheme, cadence, density, set scheme, intensity, frequency, volume and overall demands. It certainly didn't work for me - I didn't get more FT fibers as a result of my training (and I used different methods of training during my 30 years in the iron game) and I haven't seen a single person with preponderance of ST fibers who, as a result of anaerobic training along, converted his/her body into a muscle machine with predominantly FT fibers and who, following a proper training, got a tremendous muscle growth (since FT fibers are sensitive to stimulation and responsible for most muscle size and a maximum strength potential). Of course, setting aside guys on steroids and other artificial compounds. I witnessed the effect of trenbolone on an average guy.


Actually one would need massive biospies to 'see' and know actual fiber type.

but those kinds of tests are very inaccurate. Too many other factors influence 'reps with some RM' .

then knowing our fibers do alter MHC expression with training, it's really all invalid.

It's also though not so much about FT fibers, they have biopsied pro bodybuilders, they ST fibers are pretty big too and just as responsible for their size as their FT fibers.


And still the idea of transformation of ST figures in FT by means of anaerobic training looks like alchemy to me. Sharon A. Plowman, Denise L. Smith "Exercise Physiology for health, fitness and performance", Third Edition, 2011, clearly states "the difference between ST and FT fibers appears to be absolute - like the difference between black and white". From the structural aspects ST and FT differ dramatically: muscle fiber diameter, mitochondrial density, capillary density, myoglobin content. Same applies to functional aspects like contraction time, relaxation time, force production and fatigability. However, metabolic aspects of muscle fibers are not absolute characteristics as much as continuum (oxidative to glycolythic: this continuum involves shades of gray, unlike the black-or-white typing of slow or fast twitch fibers. The basic distribution of fiber type appears to be genetically determined. It is generally thought that exercise training does not alter the contractile properties of muscle fibers. The possibility remains, however, that training adaptations can alter the metabolic capabilities of muscle fibers sufficiently to change the classification of fiber types within FT fibers (that is, from FG to FOG or vice versa). It is thought that if you perform endurance type events for a sustained period of time, some of the type IIX fibers transform into type IIA fibers. However, there is no consensus on the subject. It may well be that the FG type fibers show enhancements of the oxidative capacity after high intensity endurance training which brings them to a level at which they are able to perform oxidative metabolism as effectively as slow twitch fibers of untrained subjects. This would be brought about by an increase in mitochondrial size and number and the associated related changes, not a change in fiber type.
Regarding pro bodybuilders - honestly, I would not consider them to be in human category, so in my book of things this argument is not convincing. Knowing what impact steroids and other PEDs can have on ones physique, there is no doubt that they change the structure and characteristics of muscle fibers. But we should we, mere mortals, take this into account when we talk about natural bodybuilding?
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Nwlifter

BorisV wrote:


And still the idea of transformation of ST figures in FT by means of anaerobic training looks like alchemy to me. Sharon A. Plowman, Denise L. Smith "Exercise Physiology for health, fitness and performance", Third Edition, 2011, clearly states "the difference between ST and FT fibers appears to be absolute - like the difference between black and white". From the structural aspects ST and FT differ dramatically: muscle fiber diameter, mitochondrial density, capillary density, myoglobin content. Same applies to functional aspects like contraction time, relaxation time, force production and fatigability. However, metabolic aspects of muscle fibers are not absolute characteristics as much as continuum (oxidative to glycolythic: this continuum involves shades of gray, unlike the black-or-white typing of slow or fast twitch fibers. The basic distribution of fiber type appears to be genetically determined. It is generally thought that exercise training does not alter the contractile properties of muscle fibers. The possibility remains, however, that training adaptations can alter the metabolic capabilities of muscle fibers sufficiently to change the classification of fiber types within FT fibers (that is, from FG to FOG or vice versa). It is thought that if you perform endurance type events for a sustained period of time, some of the type IIX fibers transform into type IIA fibers. However, there is no consensus on the subject. It may well be that the FG type fibers show enhancements of the oxidative capacity after high intensity endurance training which brings them to a level at which they are able to perform oxidative metabolism as effectively as slow twitch fibers of untrained subjects. This would be brought about by an increase in mitochondrial size and number and the associated related changes, not a change in fiber type.
Regarding pro bodybuilders - honestly, I would not consider them to be in human category, so in my book of things this argument is not convincing. Knowing what impact steroids and other PEDs can have on ones physique, there is no doubt that they change the structure and characteristics of muscle fibers. But we should we, mere mortals, take this into account when we talk about natural bodybuilding?


It may 'seem' like that but I guess it's not correct, once they 'see' it happen, that kinda answers the question to me...

well, many athletes show type one hypertrophy, it's not shocking actually. It's merely about stressing them in a way that stimulates them. Bodybuilders that use higher volume and mix in lighter loads are stimulating them to grow.
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hit4me

Florida, USA

S.M.Punisher wrote:
Nwlifter wrote:
I posit that the chicken had to come first, an egg can't hatch without also a chicken to sit on it, but a chicken can exist without an egg.....

I'm going with the egg. For a chicken to be a chicken, one might say that by nature it had to have come from an egg; but an egg could have been an egg regardless of whether it had come from a chicken.

You could say that for it to have been an egg capable of a chicken, it had to have come from one; but I say that for the first time the egg had been capable of anything, why not the chicken?


I believe in Genesis...so I would say the chicken came first
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