Okay, I have a question for all you scientific muscle-heads.

As I understand it, and I could be misinformed, there are 3 types of muscle fibres:

1) high endurance, low force
2) medium endurance, medium force
3) low endurance, high force

and as your force resistance is increased to muscle failure, more mucle fibres are recuited, from Type 1-3. Thus spawning the corresponding theory that high intensity training to muscle failure recruits all 3 muscle types, to their maximum capabilities.

So here is experience/question:

I have a 1 year old son, he weights 22 lbs. A couple of weeks ago I had to carry him home from the subway station, the power went out so I had to carry him from 3 subway stations away from my home. It was an hour walk. I carried him with my left arm, I'm right handed, and I didn't alternate from arm to arm for the entire 1 hr walk. When I got home, and finally put him down, my left bicep was numb. I assumed that it would work itself back to life, but it didn't. It still bothers me, so I assume that I must have strained something, probably a Type 1 muscle fibre.

Now whenever I pick him up, my left bicep hurts like hell. So I figure I'm in trouble, but here's the interesting thing: At the gym, if I try to perform 6 bicep curls with 25 lbs, my left bicep hurts, I can feel a sharp sting, deep inside the muscle, and the pain doesn't go away very quickly, it will last for several minutes after I finish the set.

But this is what's really strange, when I perform 6 bicep curls with 50 lbs, my normal curling load, no problem, I have some initial pain with the first rep, but then it goes away as the reps increase, and I have no pain after I finish the set.

So what's the deal? Does this mean that the theory of complete fibre recruitment from Type 1-3 is wrong? This seems to suggest that when my type 3 muscle fibres are working to their max, my type 1 fibres are not. Or is this just some peculiarity of my injury?

If this is the case, then HIT might not be building all 3 muscle fibres, to their maximum capabilites. And if that's true, then adding some level of low force/high rep muscle endurance training might be of value, maybe not for building maximum strength, but for an overall muscle construction that includes the type 1 fibres.

Does any of this make sense, or is it simply a muscle injury phenomenon?

Thanks in advance.

Correct me if I'm wrong, but I think you're basically saying the following:

-The sharp pain you feel in your left biceps is indicative of having neccesarily experienced a productive stimulus for muscle improvement (of a particular and exclusive muscle fiber type)

-The lingering pain you continue to experience while performing a lighter-than-usual load could indicate a selective recruitment particular muscle fiber types

-Not feeling pain while undertaking the *usual* (heavier) load indicates you are NOT recruiting the fibers in which you think you were feeling the pain

Okay, I have a question for all you scientific muscle-heads.

As I understand it, and I could be misinformed, there are 3 types of muscle fibres:

1) high endurance, low force
2) medium endurance, medium force
3) low endurance, high force

and as your force resistance is increased to muscle failure, more mucle fibres are recuited, from Type 1-3. Thus spawning the corresponding theory that high intensity training to muscle failure recruits all 3 muscle types, to their maximum capabilities.

So here is experience/question:

I have a 1 year old son, he weights 22 lbs. A couple of weeks ago I had to carry him home from the subway station, the power went out so I had to carry him from 3 subway stations away from my home. It was an hour walk. I carried him with my left arm, I'm right handed, and I didn't alternate from arm to arm for the entire 1 hr walk. When I got home, and finally put him down, my left bicep was numb. I assumed that it would work itself back to life, but it didn't. It still bothers me, so I assume that I must have strained something, probably a Type 1 muscle fibre.

Now whenever I pick him up, my left bicep hurts like hell. So I figure I'm in trouble, but here's the interesting thing: At the gym, if I try to perform 6 bicep curls with 25 lbs, my left bicep hurts, I can feel a sharp sting, deep inside the muscle, and the pain doesn't go away very quickly, it will last for several minutes after I finish the set.

But this is what's really strange, when I perform 6 bicep curls with 50 lbs, my normal curling load, no problem, I have some initial pain with the first rep, but then it goes away as the reps increase, and I have no pain after I finish the set.

So what's the deal? Does this mean that the theory of complete fibre recruitment from Type 1-3 is wrong? This seems to suggest that when my type 3 muscle fibres are working to their max, my type 1 fibres are not. Or is this just some peculiarity of my injury?

If this is the case, then HIT might not be building all 3 muscle fibres, to their maximum capabilites. And if that's true, then adding some level of low force/high rep muscle endurance training might be of value, maybe not for building maximum strength, but for an overall muscle construction that includes the type 1 fibres.

Does any of this make sense, or is it simply a muscle injury phenomenon?

Thanks in advance.


Two Types, Slow Oxidative= Type I. Fast Oxidative Glycolytic and Fast Glycolytic = Type II. You basically have it down as to what they all do without over complicating it. The large fibers are meant for heavy weight pushing and have an "endurance" meant for that specifically.

Henneman size principal. During any activity ALL fiber types are recruited. More fibers are recruited as the need arises (more weight, higher intensity, etc.)

Chances are you pry pulled a muscle or have a tendonitis of sorts.



If this is the case, then HIT might not be building all 3 muscle fibres, to their maximum capabilites. And if that's true, then adding some level of low force/high rep muscle endurance training might be of value, maybe not for building maximum strength, but for an overall muscle construction that includes the type 1 fibres.

You need to scrap this whole paragraph. HIT won't develop the type II fibres to their maximum capacities due to how it's laid out.

Personal opinions aside from HIT, doing the low weight/high repetition scheme won't do anything but change the metabolic pathways to handle that sort of activity. You can't just isolate a fibre type. It's impossible. Any intense exercise increases your muscular endurance.

In short you're developing both Fibre types while doing your lifting, with whatever you're doing and changing your approach to lifting won't fix that injury.

Correct me if I'm wrong, but I think you're basically saying the following:

-The sharp pain you feel in your left biceps is indicative of having neccesarily experienced a productive stimulus for muscle improvement (of a particular and exclusive muscle fiber type)

-The lingering pain you continue to experience while performing a lighter-than-usual load could indicate a selective recruitment particular muscle fiber types

-Not feeling pain while undertaking the *usual* (heavier) load indicates you are NOT recruiting the fibers in which you think you were feeling the pain


I'm not really sure, I guess what I'm asking is more along the lines of:

1) Is the pain that feel an indication that I'm recruiting some muscle fiber that's damaged.

if yes:

2) If I do feel pain when I perform a light load, but don't feel pain when I perform a heavier load, then does this mean that different muscle fibres are being recruited with the different loads? Does this mean that it really isn't a combined, compound recruitment of fibers?

.....
Henneman size principal. During any activity ALL fiber types are recruited. More fibers are recruited as the need arises (more weight, higher intensity, etc.)....

If this is true, then all fibers are recruited, but does this have to mean that they're all being being worked to their maximum capacity? Or is that simply conjecture?



.....
Chances are you pry pulled a muscle or have a tendonitis of sorts. ....

If this was true, wouldn't I feel pain with all loads?



..... You can't just isolate a fibre type. It's impossible....

This might certainly be true, but it doesn't have to mean that all fibres are working to their maximum capacity, or does it?



..... .In short you're developing both Fibre types while doing your lifting, with whatever you're doing and changing your approach to lifting won't fix that injury.

I agree in the sense that I'm not looking to fix my injury. But I am trying to find an explanation for why I feel pain at light loads and not at heavier ones.

You're asking good quesitons.


This might certainly be true, but it doesn't have to mean that all fibres are working to their maximum capacity, or does it?

In terms of any single muscle fiber, the activation can be considered maximum capacity. There is no middle ground as far as contraction goes. It does or it does not. That's at the microscopic level.

The only similar experience I can think of is when I would start small 2-cycle engines early in the cold morning. It involved a rapid jerk against rather low resistance, yet I felt a pain I'd describe similarly to yours. A sharp pain deep in the biceps, but only when I had to perform a movement similar to starting an engine.

I'm not sure this has to do so much with microscopic recruitment in terms of which type of muscle fiber TYPES. I'd venture to say it has more to do with the macroscopic area of the muscle which was subjected to a pretty out-of-the-ordinary task.

Varying external loads would certainly create any number of slight changes in your macroscopic form, grip, leverage etc which may be beneath conscious perception, but still create anomolous little variations in the activity of the muscle belly.

If this is true, then all fibers are recruited, but does this have to mean that they're all being being worked to their maximum capacity? Or is that simply conjecture?

Not all fibres, all three types are recruited.



If this was true, wouldn't I feel pain with all loads?

Not necessarily. Depends on alot of factors. I have tendonitis in my shin, certain things set it off like squats, but I can run and do the stair master all day with it. The best thing is to give it 4 weeks without stress and then start off with it light again. Same thing I'm doing with my leg. I'm giving it six weeks and doing all the leg machines instead of my squats.




This might certainly be true, but it doesn't have to mean that all fibres are working to their maximum capacity, or does it?


That depends on the the intensity of the exercise to determine what percentages of fibers are being recruited. More than likely all the SO fibers are activated even with minimal loads, one of the bio gurus could maybe clear this one up, I'm not sure on this but I believe this is the case as the type II fibers are for the heavy work. It is also 100% true that you can not isolate a fiber type.



I agree in the sense that I'm not looking to fix my injury. But I am trying to find an explanation for why I feel pain at light loads and not at heavier ones.

This goes beyond my knowledge. You'd have to ask a PT. I'd surmise that it might have something to do with muscular contraction at a certain point within the exercise that causes it or a constant pulling of the tendon with possibly a slow contraction with the HIT approach of whatever cadence you're using.

As Kein said, each fiber is recruited maximally. You don't have specific type II fibers that can handle loads that are heavier than any other type II fibers. Hence this is why size has a direct correlation with strength. More fibers= more force output capability.



In terms of any single muscle fiber, the activation can be considered maximum capacity. There is no middle ground as far as contraction goes. It does or it does not. That's at the microscopic level.

The only similar experience I can think of is when I would start small 2-cycle engines early in the cold morning. It involved a rapid jerk against rather low resistance, yet I felt a pain I'd describe similarly to yours. A sharp pain deep in the biceps, but only when I had to perform a movement similar to starting an engine.

I'm not sure this has to do so much with microscopic recruitment in terms of which type of muscle fiber TYPES. I'd venture to say it has more to do with the macroscopic area of the muscle which was subjected to a pretty out-of-the-ordinary task.

Varying external loads would certainly create any number of slight changes in your macroscopic form, grip, leverage etc which may be beneath conscious perception, but still create anomolous little variations in the activity of the muscle belly.

Think it has something to do with getting the blood flowing to the muscles, flexibility or just tissue damage from doing an out of the ordinary activity?

....

Varying external loads would certainly create any number of slight changes in your macroscopic form, grip, leverage etc which may be beneath conscious perception, but still create anomolous little variations in the activity of the muscle belly.

This might be the case, I could be changing the leverge slightly, adjusting to the different loads. I'll have to pay more attention to that, see if that's the case, when I go to the gym tomorrow.

......That depends on the the intensity of the exercise to determine what percentages of fibers are being recruited. More than likely all the SO fibers are activated even with minimal loads, one of the bio gurus could maybe clear this one up, I'm not sure on this but I believe this is the case as the type II fibers are for the heavy work. It is also 100% true that you can not isolate a fiber type.....


This is what I was wondering about, the percentage of fibres that are being recruited, and if somehow the heavier loads were "unloading" some of my damaged fibres?

Or maybe it's like you guys are suggesting, it's more a mechanical thing, different angles and leverages, with different loads and exercises.

This might be the case, I could be changing the leverge slightly, adjusting to the different loads. I'll have to pay more attention to that, see if that's the case, when I go to the gym tomorrow.

That's the first thing that came to mind. When you increase the weight, you often recruit other muscles and change your form slightly without even realizing it. I'd be very surprised if that isn't what's causing the difference.

Henneman size principal. During any activity ALL fiber types are recruited. More fibers are recruited as the need arises (more weight, higher intensity, etc.)

Wrong.

The Size Principle of Recruitment is that muscle fibers are recruited in order of size (from small to large) in order to meet force requirements. Small fibers (also known as Type I or Slow Oxidative) are recruited first. If all of these fibers cannot meet the force requirements, larger Type II fibers (of the Fast Intermediate variety) are recruited. If force requirements are STILL not met, the largest Type II fibers (Fast Glycolytic) are recruited. All fibers are NOT recruited in any activity. It is a sequential process.


You need to scrap this whole paragraph. HIT won't develop the type II fibres to their maximum capacities due to how it's laid out.

Wrong again, and I've explained this to you several times. I'll not do it again.

Can you provide a study that just shows only the Type I fibers being activated? There is a firing of all three types of fibers from what I've learned even within the smallest contraction and not a firing of just one type of fiber.

As for HIT. No, this is just a differerent training methodology. The HIT method doesn't even bother to train the SSC and the cadence is much too slow to properly hit the type II fibers.

Can you provide a study that just shows only the Type I fibers being activated? There is a firing of all three types of fibers from what I've learned even within the smallest contraction and not a firing of just one type of fiber.

Yeah...Henneman's and everything afterwards analyzing his conclusions. Given how the nervous system progressively recruits and increases rate of recruitment, it would not follow that partial recruitment of every type would occur.


The HIT method doesn't even bother to train the SSC and the cadence is much too slow to properly hit the type II fibers.

I've already been over this; you misunderstand the process of recruitment and fatigue.