Ændre form på muskel ved hjælp af specifikke øvelser.

[Rod]

Jeg sad lige og kiggede på T-mag, og faldt over denne artikel: HS-100: Chest specialization.

Her anbefales det at benytte forskellige øvelser til henholdsvis bredde og dybde af brystmuskulaturen. Med min MOL indoktrinering tænker jeg selvfølgelig: "hov hov, det kan man jo ikke". Forfatteren formår dog at henvise til studier der indikerer at det skulle kunne lade sig gøre, og opsummerer i følgende:

But just in case reading all other posts is a chore, here is in a single post all the things I posted regarding regional hypertrophy:

I suggest that you read the review by Kawakami (2005) available in pdf format at:

http://www.shobix.co.jp/ijshs/tempfiles/jo.../4/20050199.pdf

I present evidence that training can lead to changes in muscle architecture, pennation angle, fiber length and also that hypertrophy is not uniform throughout the whole muscle being trained.

A recent study by Keijo H?kkinen, Arto Pakarinen, William J. Kraemer, Arja H?kkinen, Heli Valkeinen, and Markku Alen (2001) mention that:

''It is also important to point out that it has been shown in younger adults that training-induced muscle hypertrophy (measured by use of MRI) can be nonuniform along the belly of the muscle.''

Meaning that it is possible to stimulate more growth in certain portion of a muscle.

Also see a study by Jose Antonio (2000) which states the following:

''Skeletal muscle is a heterogeneous tissue that exhibits numerous inter- and intramuscular differences (i.e., architecture, fiber composition, and muscle function). An individual muscle cannot be simplistically described as a compilation of muscle fibers that span from origin to insertion. In fact, there are unique differences within a single muscle and within single muscle fibers with respect to fiber size and protein composition. Electromyographic data indicate that there is selective recruitment of different regions of a muscle that can be altered, depending on the type of exercise performed. Longitudinal resistance-training studies also demonstrate that individual muscles as well as groups of synergist muscles adapt in a regional-specific manner. The author speculates that no single exercise can maximize the hypertrophic response of all regions of a particular muscle. Thus, for maximal hypertrophy of an entire muscle, athletes (particularly bodybuilders) are justified in incorporating various exercises that purportedly stimulate growth in a regional-specific manner.''

Studies by Seger et al. found that different types of muscle contraction (eccentric vs. concentric) lead to localized muscle damage in specific parts of a muscle group. Eccentric contractions creates more damage in the distal portion (near both insertions) of a muscle group while concentric contractions creates more damage in the proximal (or muscle belly) portion.

Don't get me wrong, both types of muscle contractions creates damage on the whole muscle, but the relative amount of damage to different portions of a muscle is contraction-specific. That result is an indirect indication that it IS possible to put more training stress on different portion of a muscle group.

Furthermore, more recent physiology research has found that not all muscle fibers run all the way from one insertion to the other; many muscle fibers are actually intermediate fibers that only cover a small portion of the muscle length.

While these fibers do not represent the majority of the fibers within a muscle group, they still form a significant portion of the motor unit pool. If certain muscle fibers cover only a portion of a muscle, it also indicates that it is possible to place more growth stimulation on certain parts of a muscle.

Finally the fact that different parts of a muscle group can get sore depending on the exercises being performed is also an indirect indication that putting more growth stimulation on certain parts of a muscle group is possible.

Regarding the ''danger'' of neck press; no exercise is 100% safe, and this one is no more dangerous than other movements if performed correctly and if there is no pre-existing shoulder problem.

However I'd like to say that more effective techniques and exercises tend to carry a greater risk of injuries... lifting heavy weights is potentially more dangerous than lifting baby weights... movements such as the olympic lifts, squats and deadlifts are potentially more dangerous than biceps curl and triceps kickback..., lifting fast is potentially more dangerous than lifting slowly, etc. Does that mean that we should all limit our lifting to loads under 50% of our max on isolation exercises using a slow tempo?

Here's another study that indirectly demonstrate that not all muscle fibers run through the whole muscle:

Sakuma et al. (2004) studied nonuniform hypertrophy and muscle fiber distribution and found that different parts of a muscle group (proximal, middle and distal) had a different muscle fiber makeup.

''(...)the percentage of type I and IIA fibres in the middle region were higher than that of the proximal and distal regions''

NOW how does that tell us that muscle fibers do not all run through the whole muscle length? Well, if different regions of the muscle (at the proximal, distal ends of the muscle and in the muscle belly) have different percentage of each muscle fibers that means that some region has more of certain types of muscle fibers... which indicates that muscle fibers do not all run through the whole muscle length, otherwise muscle fiber makeup would be the same throughout the whole muscle length.

So this shows that:

1. Some fibers indeed run through the whole muscle length

2. Some fibers are intermediate fibers that are only running through the distal portion of a muscle.

3. Some fibers are intermediate fibers that are only running through the proximal portion of a muscle.

4. Some fibers are intermediate fibers that are only running through the middle portion of a muscle.

NOW, if some fibers are only found in one region of the muscle; isn't it possible to stimulate more hypertrophy in certain parts of the muscle by placing more growth stimulus in the fibers present only in that specific region?

Senere i debatten modargumenteres der dog med

It seems CT focused on three areas to support the regional hypertrophy via exercise selection argument.

I'd like to point out that the argument that a muscle grows non-uniformly is not also an argument that EXERCISE SELECTION can be used to target specific regions.

Example:

The very first point CT raises is the differences in muscle trauma between eccentric and concentric repetitions. While this may indicate some degree of regional hypertrophy differences between, say, doing eccentric only reps and concentric only reps, it is inapplicable to any form of training where we do both, as far as I can tell. And even with different exercise selection as per the original article, we're still employing both concentric and eccentric reps.

The second argument concerns intermediate fibers not running all the way through a muscle. I.e. there are localized distributions of certain muscle fibers.

While this again would point to the possibility of non-uniform growth, it does NOT support the claim that exercise SELECTION alters this. Because the force demands are still met incrementally by tapping into a progressively larger pool of fibers going from I - IIa - IIx.

This might mean that regions with a higher distribution of, say, fast twitch fibers would represent regions more likely to grow from exercise. But it does NOT imply that exercise selection affects this, since their recruitment is a matter of force demand, not exercise selection.

The third argument concerns regional soreness. While there is limited evidence that DOMS may be connected to growth/remodelling, I'm not sure how it would support divisions like 'width' and 'thickness.' Further, I'm not sure the evidence is really there to extrapolate that much based on soreness alone, given the confusion about what exactly it represents.

Now obviously for something like pectoralis major, it would be possible to emphasize clavicular vs. sternal head based on the movement selected in respect to function (i.e. flat vs. incline bench). But suggesting that wide grip targets the 'outer' chest while something like flies or close grip targets the 'inner' chest doesn't seem supported by the literature, or in the least, the argument presented.

Jeg anbefaler hverken den ene eller anden vej, men tænkte at det måske kunne spæde lidt til debatten og være af interesse for andre . Er der nogen der har tilpas indsigt til at se hvor meget hold der er i det?

- Rod

[incognito]

Meget groft sagt er CT en avekat der giver brænderfolket hvad de vil have, ikke hvad de har brug for...... At han nævner at han har en BSc og MSc i denne sammenhæng er direkte spottende for den øvrige akademiske stand.....

[Kauf]

Meget groft sagt er CT en avekat der giver brænderfolket hvad de vil have, ikke hvad de har brug for...... At han nævner at han har en BSc og MSc i denne sammenhæng er direkte spottende for den øvrige akademiske stand.....

You said it, man :4thumbup: :4thumbup:

[Francis]

er det christian Thibileau(osv osv) ?

[Dines]

Læste det review han henviste til i starten og må indrømme at det med pennation angle er nyt for mig, men udover det, så er der ikke rigtigt noget der tyder på at man kan ændre formen på sine muskler. Fordi en sprinter har længere muskler end en maratonløber, behøver det jo ikke at være opstået via træning.