Upper abs, lower abs. Upper pecs, lower pecs.

Wai Jia: The Kung Fu Forum Kung Fu Training and Health
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Alright. I found the post about pecs I was referring to in another thread.

All this info is “as far as I know.” It will take some very convincing evidence to change my mind, so unless you’re Ford Prefect or El Pietro don’t bother trying :smiley:

Once again, let’s review the basics.

1. You cannot work part of a muscle head more than another part of the same muscle head.

Example: The lateral head of the tricep, regardless of the exercise performed, will either completely contract or not contract at all. You cannot contract part of it more than another part.

2. Different heads of a muscle, with their own insertion points, can be targeted differently.

Example: In a certain tricep exercise, the lateral head may be doing 40% of the work. In another tricep exercise, the lateral head may be doing 45% of the work.

Pecs
The pectoralis major has two heads: the Sternal head and the Clavicular head.

Sternal head (“lower pecs”)
This is generally what people think of when they say “pecs.” It comprises the majority of the “pecs.” You can see it here. See how big it is?

Clavicular head (“upper pecs”)
This would be considered the upper pecs. It is small when compared with the Sternal head. You can see it here.

Now, whenever you do any chest exercise, both heads of the Pectoralis Major are activated. Remember rule number 2 above? It is possible to place different amounts of stress on the two pectoral heads with different exercises. The difference in stress between flat bench and incline bench is not as great as people would like to believe, however.

Important note about working the upper pecs
Please go look at the picture of the Clavicular head again. Do you see how high it is, and how small it is? Those are your “upper pecs.” Do you remember rule 1 from above? When most people talk about working their “upper pecs” they are referring to the upper portion of their Sternal head. They think they are somehow placing more stress on the top part of the Sternal head by doing incline bench press, which, because of rule number 1 above, is not possible.

That is where the confusion comes from.

Abs
Please remember rule 1 while you read this entire thing.

The rectus abdominis is one muscle. See? Since it’s one muscle, and we have rule number 1 from above which states that differents amount of stress cannot be applied to the same muscle, there is no reason to further explain this. Your entire rectus abdominis contracts or none of it contracts. Part of it does not contract harder than another part.

Conclusion

When most people think they are working their upper pecs, they are not talking about the Clavicular head. They are thinking that they are working the upper portion of the Sternal head, which is not possible (rule 1)

When anyone thinks they are working their upper abs more than their lower abs, or vice versa, they are wrong.

IronFist

*Thanks to wooha for providing these links in another thread.

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nice.

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Thanks. :slight_smile: Is everything clear in it?

We should make this thread sticky so we don’t have to repeat ourselves every week when the same questions get asked over and over again.

IronFist

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Re: Upper abs, lower abs. Upper pecs, lower pecs.

Originally posted by IronFist
1. You cannot work part of a muscle head more than another part of the same muscle head.

Example: The lateral head of the tricep, regardless of the exercise performed, will either completely contract or not contract at all. You cannot contract part of it more than another part.

2. Different heads of a muscle, with their own insertion points, can be targeted differently.

Example: In a certain tricep exercise, the lateral head may be doing 40% of the work. In another tricep exercise, the lateral head may be doing 45% of the work.

Hitting the muscles from different angles is possible, eh…

Any idea just how different the load on the triceps is for common exercises such as dips, french press, decline bench press, push downs, and tricep extensions?

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If you want the specific amount of work done by each head in those exercises, I don’t know. I think I saw it in a book once, though. It had a cross section of the muscle and it was shaded according to how much each head is hit by the different exercises.

I’m not sure how accurate it was, but I do remember that part. I can’t remember the name of the book, though. Wait, I think it was called “Explosive Growth.” I saw it at Borders.

Again, I don’t vouch for the accuracy of the information in that book, I just said I think that might be the book I’m thinking of. I’m only about 50% sure, because I looked through it in the store a few years ago.

Sorry.

IronFist

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hey ironfist :slight_smile: nice post. i swear i remember reading you proclaim that there was no upper and lower pecs at all - that incline press and decline press only differ in their utilisation of the deltoids/vs pecs.i hate using this msg board, posts from me always seem to come across as being either officious, arrogant or too humble.

anyway - (dont take offense smiles winningly ) i’m confused. people that i talk to about ‘upper pecs’ don’t make any reference to the ‘size’ of their upper pecs. they just reckon that incline press places more stress on ‘upper pecs’ than the ‘lower pecs’. i took the impression from you that this was bull****. maybe i just misunderstood you, but i dont usually do that. what am i looking for? not an apology. maybe a cold beer. maybe a warm bed and a girl in it. i won’t read this thread for days - my time is consumed by me wasting it by being a foolish teenager.

good luck to everyone with their pursuits.

martin neilson

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What was that middle part?

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Yay! Thanks. That was free with no grave robbing or dissection involved.

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By Ironfist
It is possible to place different amounts of stress on the two pectoral heads with different exercises. The difference in stress between flat bench and incline bench is not as great as people would like to believe, however.

What exercises do place greater stress on the clavicular head?

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IronFist is good!

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consider it stuck.

in the future, if you want something stuck or unstuck, or are having problems with other members*, or have questions, just PM me. i’ll get to it sooner if you do it on PM.

*if you’re having problems with your own member, do NOT PM me. i do not want to hear about it.

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Someone slap IF in the lower pec and tell him to answer my question.

:slight_smile:

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I don’t know exact percentages. Incline bench is supposed to work the Clavicular head more than flat bench, but I don’t know if it works it harder than the Sternal head. I guess you could vary the angle of the incline until you find the position that works for you.

Unless you’re like me, in which case incline bench is about 90% front delts and 10% pecs. My shoulder structure is different from most people’s and my front delts always overcompensate for what I’m doing. For example, all I do is flat bench, and I still get a huge pump in my front delts. I never do additional shoulder exercises (for any of the three deltoid heads) and my shoulders (all three heads) are my best body part (from a bodybuilding perspective). I’ve tried many ways to counter this, but it seems that’s just the way the muscle recruitment in my body works. I wonder if the fact that I have wider shoulders than most people has anything to do with it?

But yeah, I think that standing front deltoid raises would probably hit the Clavicular head a bit, too, since the muscle is used to help raise the arm. I forgot the name for this exercise, but it’s the one where you stand with a dumbell in your hand and raise it until your arm is horizontal in front of you. It’s primarily a front deltoid exercise.

That being said, it’s impossible to isolate either of the deltoid heads, so just play around and find some angles or whatever that for you seem to hit the Clavicular head more. That’s the best advice I have. Sorry.

IronFist

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Go back and tell us all why it FEELS like the upper abs are more tired, or it FEELS like the lower abs are worse off

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well?

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The Abs are genetic ex. six pack four pack

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The upper pec is also an insertion with the deltoid.

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Originally posted by Sharky
well?

Ok, chill out :slight_smile:

It must be your imagination or something. Or maybe you’ve stressed other, smaller muscles around the abs that you mistaking for abs… hip flexors are common in this case.

IronFist

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Like I said in the other thread, Hip Flexors = Lower Abs to the Layman.

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By the way, i feel the need to point out that i already knew this, but it’s what everyone asks whenever i tell them that it’s one muscle.

I had to post this otherwise i might not look like the don that i am.