Common misconception about working different parts of same muscle

Wai Jia: The Kung Fu Forum Kung Fu Training and Health
21

Are you talking about the individual heads of a tricep being stressed differently on different exercises?

Ironfist, that may have been a bad example being that the Tri-cept does have the different heads. (outside of arm and backside of arm. My point was that I dont beleieve a certain part of a muscle can be flexed, the whole muscle has to be flexed but the concentration on the different striations in your muscles can be concentrated differently via the use of different angles. Do we really think that bodybuilders chest’s would look that way if all they did was flat bench? I dont think so, in fact, I know so.

What do you guys think?

AOF

22

You can work different parts of your chest. There are 4 muscles in your chest: Pectoralis Major Sternal, Pectoralis Major Clavical, Pectoralis Minor, and Serratus Anterior. Different chest excercises target different chest muscles to an extent, such as switching from incline to decline bench. However, because of somebody I can’t remember right now’s law, when one muscle tenses, so do the sorrounding muscles. You can’t work just one of the chest muscles, but you can work it more than the others. You also can’t flex just one of them for the same reason. See this link and click on the names of the chest muscles to see the anatomy: link The same goes for biceps, there are bicept bracci and braccialis, except there are no upper or lower biceps, just one muscle under and to the side of the other. The abs are one muscle, so you cannot concentrate on parts of them.

23

Originally posted by Arhat of Fury
the Tri-cept does have the different heads. (outside of arm and backside of arm.)

Actually it’s got three heads, tri-ceps. :slight_smile: But that doesn’t matter.

Do we really think that bodybuilders chest’s would look that way if all they did was flat bench? I dont think so, in fact, I know so.

Yes, they would look the same (within the parameters of muscle growth). In other words, a Bodybuilder’s “upper pecs” will not change because he does incline bench.

Here we go:

You can work different parts of your chest. There are 4 muscles in your chest: Pectoralis Major Sternal, Pectoralis Major Clavical, Pectoralis Minor, and Serratus Anterior. Different chest excercises target different chest muscles to an extent, such as switching from incline to decline bench. However, because of somebody I can’t remember right now’s law, when one muscle tenses, so do the sorrounding muscles. You can’t work just one of the chest muscles, but you can work it more than the others.

Alright. The Pectoralis Major Sternal and P.M. Clavical are different muscles. Yes. But this isn’t relevent to the discussion because when people talk about working their “upper pecs” they are talking about the top portion of their Pectoralis Major Sternal. Besides, as far as bodybuilding goes the Pectoralis Major Clavical is kind of small. It gets worked, but it is overshadowed by the pec Sternal and Deltoids.

Again, when someone says "I’m gonna work my “upper pecs,” they’re not talking about their Pectoralis Major Clavical.

The reason people think there is a difference between upper pecs and lower pecs is because some Bodybuilders, such as Franco Columbu, have such (genetically) ripped chests that you can see a line between “upper pecs” and “lower pecs.” Bodybuilders assumed that you can work these two portions OF THE SAME MUSCLE seperately, much as people assume you can work different portions of your abs seperately.

Ok, one more time:

It is impossible to work certain parts of the same muscle head with more or less stress than other areas of the same muscle head. As far as I know, it is possible to stress the clavical more than the sternal, because these are two DIFFERENT muscle heads.

K, I’ve got some homework to do so I’m gonna run.

IronFist

24

Yes, they would look the same (within the parameters of muscle growth). In other words, a Bodybuilder’s “upper pecs” will not change because he does incline bench.

Ironfist, I do not agree with you on this. I have seen a dramatic change in my anatomy since I have laid off the incline and focused more on flat bench. Also, if you are an experienced weightlifter you know exacly whats it like to start your chest work out with flat and then switch to startig it with incline, the pump is completely different. With that in mind there would have to be different stress ratios and different areas of the muscle(or heads) that are working harder. But enough with the opinion talk, I have read this somewhere in one of my Arnold books, where an unbiased doctor did a study on this concept… Let me get that info for us:)

Anyway after thouroughlly reading your post it seems we are all capitulating the same idea which is.

You cannot work, flex or concentrate stress on certain part of a muscle head, however you can work the same muscle from different angles to promote different stress when it contains more than one head or more than grouping of striations.

Agreed,

Amitoufu,

AOF

P.S.- My guess is that all the times that this topic has been argued, folks on the board have been asking the question wrong. Instead of saying “can I concentrate stress on certain paert of my bi’s, chest, tri’s or cuads”, they have been saying "can I work out/or flex my upper chest only, when in fact the whole muscle grouping has to work, just some parts more than others----

25

Braden,

Yes, there is a reason. Flies are a chest exercise…close-grip bench is primarily a tricep exercise. However, if during close-grip bench you feel it more in your chest than your tris, I’d suggest having a trainer check your form…you may be flaring your elbows out too wide and doing this a lot can eventually put too much pressure on the shoulders.

If somebody told you close-grip bench was an “inner chest” exercise, smack them. See above posts for why.

26

Arhat of Fury, the Arnold book, while very inspiring and full of information, is also full of anatomical errors :slight_smile:

When your pectoralis major sternal muscle fires, the entire muscle fires at once. Nothing in the world can make part of it work harder or less hard than another part of it. The only thing that you can change is how much the entire muscle works.

You can change the ratio between Pectoralis major sternal and pectoralis major clavical usage, but that is different.

You said:
I have seen a dramatic change in my anatomy since I have laid off the incline and focused more on flat bench

That’s because flat bench stresses the entire pectoralis more so than incline bench does. Incline bench causes the front deltoids to work harder than they do on flat bench. So, your chest has probably gotten bigger because you are working it more. It has nothing to do with working the “middle” or whatever of your chest more, it has to do with placing more stress on the chest.

I gotta go to class now. Please find the references you were talking about in the Arnold book, because if it’s the one I’m thinking of then it’s wrong :slight_smile: However, I left my copy of the book at home this semester so I’ll take your word for whatever it says.

IronFist

27

Iron,
Yeah, i will dive into the library tonight and get back to you.
Now, this has gotten me real curious.

Amitoufu,

AOF

28

Sorry to disappoint you guys, but muscle shape is genetically determined…all you can do is influence it’s size…and that also has a genetic maximum. You can break the maximum size through the use of anabolics…but for shape please go stand in the synthol line because without injections you won’t be able to do anything else about it.

29

lol, synthol line :slight_smile:

IronFist

30

Silumkid - Thanks, I thought I was being ignored. :wink: That makes sense (I actually haven’t done close-grip bench in years, but you’re right, back when I did them I was convinced they were for ‘inner chest’ :wink: ). However, I really just chose them as an extreme example. None of mid -> wide grip benches, a variety of push-ups, or even flies done horizontal build my pecs the way the decline flies do. Now I’m not challenging the theory laid out here; I’m just curious because I swear that’s what goes on with me. :wink: Will the other exercises do the same; maybe I’m just not working them hard enough? Could this be due to simple individual difference in my pec shape - ie. this motion capitilizes best on my shape, but maybe something else is best for you? Is there something anatomical going on, like differential working of muscles that balance the pecs in the exercises? Or should I just check for gas leaks where I work out?

BTW, just bouncing off something IronFist said in a related thread - if pecs are for pulling your arms closer to your body, why do more people think ‘bench press’ as the epitome of chest exercises, rather than the fly?

On a completely unrelated note, I’m working on doing handstand pushups now. They’re so much harder than I thought they’d be. ;p

31

Sigh. I’m more confused than i was before now.

Let me get this straight - it is IMPOSSIBLE to work one part of the SAME muscle more than another part. You are merely targeting the muscle more by doing different exercises?

The reason the “lower abs” seem to be worked when doing leg raises is cos it’s working your hip flexor muscles - cool.

The reason that when you do close-gripped bench press it seems to work your “inner pecs” more is…?

Cheers

32

…only in your mind.

muscle fibres run horizontally in the pectorals…muscle fibres are recruited on an all-or-nothing basis. There are two parts to your chest, however stimulating one and not the other is not possible. By lifting heavy you will be recruiting maximally from both pec major and minor. I believe the ideal position for bench is a very slight incline, however, as i said if you are lifting maximally then you are recruiting maximally, simple as that. You do not necessarily have to use bench press…I use it because it is a very effecient exercise…i am working my chest, triceps, shoulders, and many other stabilizers. The isolation exercises such as flies are also good for chest however you are not working many of the synergistic muscles that will inevitably be used in any functional movement involving the chest.

33

Iron-
I cannot find the book, it was a black cover with green writing and a picture of Arnold, Flexing his back while leaning on a brickwall face first. I dont know what happened to it. Probably lent it to one of the guys I was training.

Anyway, I still do not agree with the statement that you cannot make a different strands or heads of muscles fire harder using different angles. I would be willing to put my shirt on it.

DOES ANYONE HAVE ANY UNBIASED DOCUMENTATION TO PROVE THESE ALLLEGATIONS EITHER WAY!

I will keep searching for scientifical facts on this, until anyone care to share.

Amitoufu,

AOF

34

Just buy an anatomy book. Preferably one that wasn’t written with any sort of exercise in mind. It’s actually widely accepted fact. Muscle Mags lead to a lot of misinformation. Just looks at how many people still believe in spot reduction. (ie doing a bunch of crunches will make you loose fat around the abs) It’s pretty amusing.

35

Originally posted by Arhat of Fury
make a different strands or heads of muscles fire harder using different angles.

HEADS, yes. Strands as you put it, no. Different “heads” are essentially different muscles, as they have THEIR OWN INSERTION POINTS. Let’s use the triceps as an example because I’m sick of talking about pecs.

The triceps have three heads, lateral, long, and something else which I cannot remember at the moment, so for simplicity’s sake we will call them Head 1, Head 2, and Head 3. “Triceps” is actually a group of these three muscles, but people just refer to them as “triceps” because it’s easier than saying “I’m going to go work the three heads of my triceps.”

Now, different exercises may recruit the different heads (each with their own insertion points) in different ratios. Let’s assume a hypothetical measure of power output called “p” (for “power” :slight_smile: ).

Exercise 1 may recruit the triceps’ heads like this:
Head 1: 200p
Head 2: 300p
Head 3: 300p

Exercise 2 may recruit the heads like this:
Head 1: 800p
Head 2: 600p
Head 3: 600p

However, the stress placed along a SINGLE head at any certain point will NEVER be more than at any other point in the same head.

For example, during Exercise 1 above, EVERY point on head one will be contracting at a level of 200p. This includes “upper,” “lower,” and everything in between.

Now, let’s apply this to pecs.

Incline bench may recruit the Pectoralis Major Sternal less than flat bench, but throughout the entire Pectoralis Major Sternal the contraction will be exactly the same (in other words, the “upper” part is working just as hard as the “lower” part). This may differ from the amount in which the Pectoralis Major Clavical is contracted in the same exercise, but this is because Pectoralis Major Clavical and Pectoralis Major Sternal are different HEADS.

Now, the confusion comes in, I believe, because some people may be referring to the “upper section of the Pectoralis Major Sternal” by “upper pecs” while other, albeit a few people, may be referring to the Pectoralis Major Clavical, which is an entirely different muscle head.

Make sense? I have to go to class now :slight_smile: Use the link above if you want to see pictures of the muscles I was talking about.

IronFist

36

Braden,

What Iron said is correct, the “primary” function of the pec is to draw the arm across the body. It is also involved in front or “away” pressing motions such as a punch.

ElPietro also nailed on why it is done so often…efficiency. It can also be used to monitor and correct muscle imbalances. Very generally speaking, if a person tends to hit “sticking point” at the lower part of the bench, it usually means weak pecs. If they tend to stick more towards the middle, it usually means weak triceps.

Now, as to why one exercise may work for you better than it might me…one simple rule applies. No one responds to exercise exactly the same. This is true in regards to muscular response, recovery, fiber recruitment, fiber ratio disposition…and now we know why there are so many books on this seemingly simple subject. sigh

Sharky,

I think you read the posts wrong…you SHOULDN’T feel close-grip bench in your so-called “inner pecs” more. It’s a tricep exercise.

Arhat,

Some of the best books I have ever seen on these subjects are:

Getting Stronger - Bill Pearl
Just about anything by Fred Hatfield

I can’t recall if they address this particular subject exactly though…Hatfield’s stuff probably does.