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alexamezaga1 wrote:I have a question about classes of muscle fibers: I have seen both type IIb and type IIx muscle fibers from different sources, but no sources include both. Are these just different names for the same thing?

Pretty sure they are the same thing. The muscles fibers types are as I know:

Slow Oxidative Fibers (SO) Type I
Fast Oxidative-Glycolytic fibers (FOG) Type IIa
Fast Glycolytic Fibers (FG) Type IIb

alexamezaga1 wrote:I have a question about classes of muscle fibers: I have seen both type IIb and type IIx muscle fibers from different sources, but no sources include both. Are these just different names for the same thing?

Yes, they are both the same type of muscle fibers. (fast-twitch)

Terbin73 wrote:

alexamezaga1 wrote:I have a question about classes of muscle fibers: I have seen both type IIb and type IIx muscle fibers from different sources, but no sources include both. Are these just different names for the same thing?

Yes, they are both the same type of muscle fibers. (fast-twitch)

Based on my (1 minute-long, admittedly) research, they are different (I found a source discussing the effects of the ratio between the two types).

Unome wrote:

Terbin73 wrote:

alexamezaga1 wrote:I have a question about classes of muscle fibers: I have seen both type IIb and type IIx muscle fibers from different sources, but no sources include both. Are these just different names for the same thing?

Yes, they are both the same type of muscle fibers. (fast-twitch)

Based on my (1 minute-long, admittedly) research, they are different (I found a source discussing the effects of the ratio between the two types).

Really? On http://greatist.com/fitness/what-are-fa ... ch-muscles, they are both referred to as the same thing.
This quote - "Fast-twitch muscles break down into two categories: moderate fast-twitch (type IIa) and fast-twitch (type IIb or IIx)." explains it.
Here is another quote from http://athletics.wikia.com/wiki/Type_II_Muscle_Fiber. "Type IIb fast-twitch fibers, or fast glycolytic fibres (also known as Type IIx), are recruited for very short-duration high-intensity bursts of power such as maximal and near-maximal lifts and short sprints.
Could you please link me to the article that you found

Terbin73 wrote:

Unome wrote:

Terbin73 wrote:
Yes, they are both the same type of muscle fibers. (fast-twitch)

Based on my (1 minute-long, admittedly) research, they are different (I found a source discussing the effects of the ratio between the two types).

Really? On http://greatist.com/fitness/what-are-fa ... ch-muscles, they are both referred to as the same thing.
This quote - "Fast-twitch muscles break down into two categories: moderate fast-twitch (type IIa) and fast-twitch (type IIb or IIx)." explains it.
Here is another quote from http://athletics.wikia.com/wiki/Type_II_Muscle_Fiber. "Type IIb fast-twitch fibers, or fast glycolytic fibres (also known as Type IIx), are recruited for very short-duration high-intensity bursts of power such as maximal and near-maximal lifts and short sprints.
Could you please link me to the article that you found

Now you have me curious too Unome. Most sources I have read will distinguish at most 3 muscle fiber types. Sooooo are you saying there are four muscle fiber types?

Mystery solved.
https://books.google.com/books?id=BC9Si ... le&f=false
Type IID/X was isolated in rat diaphragm, and its homolog in humans is type IIB. So some people adopted type IIX to be politically correct. So it's different in rats but the same in humans.

Uber wrote:Mystery solved.
https://books.google.com/books?id=BC9Si ... le&f=false
Type IID/X was isolated in rat diaphragm, and its homolog in humans is type IIB. So some people adopted type IIX to be politically correct. So it's different in rats but the same in humans.

Good job, Uber

sciolyFTW_aku wrote:

Uber wrote:Mystery solved.
https://books.google.com/books?id=BC9Si ... le&f=false
Type IID/X was isolated in rat diaphragm, and its homolog in humans is type IIB. So some people adopted type IIX to be politically correct. So it's different in rats but the same in humans.

Good job, Uber

ahaha the case of the Muscle Fiber Type IIx has been solved!!!!

Fluorine wrote:

sciolyFTW_aku wrote:

Uber wrote:Mystery solved.
https://books.google.com/books?id=BC9Si ... le&f=false
Type IID/X was isolated in rat diaphragm, and its homolog in humans is type IIB. So some people adopted type IIX to be politically correct. So it's different in rats but the same in humans.

Good job, Uber

ahaha the case of the Muscle Fiber Type IIx has been solved!!!!

Aha! Now I understand. I guess both of us were right

Does anyone have a good source for different muscle groups and their included muscles? For example the quadriceps (It's the only group I've been able to find)