Isolating muscle part conflict!

I noticed tha bbuilders love to switch exercises reguralrly (and their variations) to “hit” various part of muscles. But is this really possible?
Here is what Pavel Tsatsouline have to say regarding this in his excellent book Power to the people:

Thus according to Tsatsouline, one can only slighly hit different muscles and not different part of the muscles, due the random organiyation of MUs in muscles.
Also, Tsatsoulne don’t love to change a lot of exercises to hit various muscles… he uses hyperirradiation to hit them using compund exercises. Slight change in grip, stance etc is enough.

For building mmas Tsatsouline recomends:

Ok, this will surelly build mmass, but what about “polishing” and “details”…
For mmass and body transformation, I love to listen to advice from Chris Thibaudeau… His and Anthony Robertson new book is very nice regarding this topic…
Anyway, I noticed that Thib’s phylosophy is not with the agreement with Tsatsouline opinion about “hitting” different parts of the muscle.
This is originally posted at t-nation.

When I asked Thib (second page) about this:

He responded:

My current opinions is that Thib’s approaches are great for mmass increase and finalization (specialization on body part, details), and that Tsatsouline approach is great for packing mmass for athletes. BBuilders can start with Tsatsoulie approach and then hit the Thib’s specialization program…

Anyway, I want to know what do you think about this conflict----is it posible to improve/hypertrophy a given part of an individual muscle???

Hw come that some of muscle parts shows greater activity (MRI scans) when individual fibers from particual MUs are evenly sread over the whole muscle (thus it is unable to contract only one part)… ???

individual muscle shape is genetically predetermined period. anyone who tells you different deosnt kno the first thing about muscle physiology. doing a bicep curl a certain way will not make the bicep peak. individual muscles can be hypertrophied to give a certain look but this has nothing to do with athleticism.

I am on your side James, but how do ye explain findings by Per Tesch? He showed that various exercises hited different portions of particular muscles by using MRI scans… What is the mechanism of this…

id have to see the data for myself. the thing with studies is a lot of time they are not conducted in a practical manner. in recent years ive lost a lot of faith in the validity in most studies and will not take their findings serious unless i see what methods they used to reach those conclusions. for example MU population in a single individual can account for the different activity duding various movements, how many people did they test? i wont dwell on this topic too much as this has absolutly nothing to do with athleticism and im not interested in bodybuilding methods.

This isn’t what Muscle Meets Magnet showed

the confusion is over hitting different mucscles (i.e. biceps long vs. short head) versus hitting different parts of the same mucle (i.e. upper biceps long head vs .lower biceps long head).

TEsch’s data showed taht different movements can hit different muscles which are often grouped together. Most of which could be predicted based on anatomy (i.e. rectus femoris which crosses hips and knee isn’t hit by many movements which hit the other qudriceps because the hip is in flexion and not extension).

So the hamstrings consistent of biceps femoris (long and short head), semimembranosus and semi-tendinosus. Which can be hit somewhat preferentially with different movements.

Which is a far cry from saying you can work the upper part of the biceps femoris long head or whatever.


tis is what i figured duxx was talking about i was suprised when he said that there was data supporting the claim that different parts of an individual muscle can be trained with differnt movements.

Thanks Lyle for clearing this mess!!!

Based on what have Thib answered me and based on what he have wrote in his article I have understood that he is saying about hiting different parts of the same muscle.

This was suspisious to me all the time, because I know that muscle fibers of a single MU are evenly distributed over the whole muscle, not just a part of the muscle, thus the “hitting” only one part is nearly imposible.
Anyway, what about neural compartments found in obliques externus muscle??? Stuart McGill explains in his book “Low Back Disorders”, that for “hitting” this muscles and his different neural compartments a couple of exercises must be performed. (dont have a book near by so I can’t tell the page). Anyway, this is not the case with rectus abdominis.
How come that there are neural compartments, when the MUs and their muscle fibers are evenly distributed over a muscle???

Are you Lyle McDonald??? if yes then great to have you here!!


There’s only one Lyle!

One thing i am quite interested in is the whole isometric length/strength relationship. I remember talking to some researchers way back when MedX first brought out the Lumbar Extension machine and they were saying one thing we don’t know is if it is necessary to get the muscle strong in every part of the range of motion. They thought that for back patients it seemed to make quite a difference in that often where there was a swing away from the norm in a certain position during maximal isometric contraction then working on this point often resulted in a dramatic reduction in pain for the patient. It worked for me when I had some back problems. So while it isn’t so much hitting long head vs short head etc perhaps making sure you are strong through the full ROM is very important and perhaps also important for hypertrophy?

Way back when… there were no scientests about to do this testing, Arnold and Franco did the testing, on themself’s. Arnold says, to find out where a exercise hits you, do 20 sets of 20reps, then the next day you will find out.
i have seen plenty of rubbish about 300lb bodybuilders talking up that you only need to do 1 type of lift to develop each muscle. Crap. And they might be 300lb, but they look like crap too.
By 19 or 20, arnold was Massive, actually more massive than he was when he was 28 and Mr o for like 6 times and as strong as he ever got, But he was looking much better. He learned that to develop muscles that looked good, you needed many different exercises, and variations. Eg, he always changed hand position on the bar for bench presses.
Only just today, i was noticing that as i have lost 7kg of fat in the last 4mnths, that as i twist different joints, the musles change shape, something i have always known but i was thinking about it today, then this comes up!
I am not a big bloke by any means, but i have deffinition and seperation from doing many different exercises over a period of time that i would not have had just doing a few basic exercises.
Try doing Hammer bicep curls for 2mnths without any other bicep work at all. then do the same weight for regular bicep curls, and feel the differnent pain the next few days. It hits the bicep totally different in a totally different manner.
Stop looking at the massive bloated monkeys from today and look from at big well built guys from yrs ago. back when it was not just about being big, but cut, seperated, defined and well balanced. Big Lue (the incredible hulk), was massive even by todays standards, but his physique lack detail, seperation and balance, then look at how he did his training in pumping iron, Half reps and just basic.

Regarding hitting different muscles of same muscle group:
Doing some exercises variations (like hammer curl instead of ordinary curl, pull-ups with wrist in pronation instead in supination) may recruit different muscles in muscle groups differently. This is mainly due “force sharing” of muscles with the simmilar (sinergitic) function (Enoka, 2002). The system is reduntant, and there may be different control strategies for different people… Thus, the elbow flexion torque may be created by using force production from biceph brachii, brachialis or brachioradialis… How the system recruits them and how it “shares the force” ammong them is a problem of motor control… (man I love motor control issues :slight_smile: )

Regarding hitting different portions of same muscle:
According to any good physiological book, muscle fibers from the indiviual motor unit (MU) are NOT grouped together but rather evenly distributed over the muscle. This basically means that the whole muscle is being contracted (not all fibers, but muscle as a whole rather than his individual parts — upper, lower etc).
Accodring to this, one is unable to recruit different parts of the same muscle. But…
First answer me this question: what is muscle?
Some muscles have neural compartments, and thus recruiting one compartment only one part of the muscle will recruit. This is the case is external obliques. This basically means that there are two or more “muscles” in one individual muscle which we indentify by his anaotmical name. For example iliopsoas are basically two different muscles, with different recruitments — psoas major and iliacus…
One should first find are there any neural compartments before making any claim that hitting different portions of the same muscle is inposible.
Biceps brachi have two head with different attachments… They are called as one muscle, but are they one muscle…

Regarding muscle detailing:
Estetical (morphological) details for bbuilding are very freaking important, and for athletes they are not.
I look at this like making a statue. First you use “hard process” (building mass in general via compund exercises) and then finishing with very “precise details” (specialization exercises for muscle details). This is how Michelangelo did his statues :slight_smile:
For athletes wish to build mmass, “hard process” is enough. Hard process includes general strenght exercises (compound) that his a lot of muscle groups. For this issueas I would use Tsatsouilne approach of building “russian bears”. Doesnt word bears associat to someone having a lot of mmass but few details??
For bbuilders this is just one part of the equation… they need details (whether we liked it or not). And these details are achived with specialized exercises, variations of compund exercises (grip etc), specialized periods (emphasising shoudlers, pecs etc.). Some may use pre and post fatigue techniques, doing compund exercises with specialized-isolation exercises in supersets.

On my opnions specialized exercises for bbuilding issues are a MUST (talking about the details)…They (bbuilders) must include various grips, cycle different exercises wheteher or not we know their mechanism (let the science do its “historician” job :slight_smile: ). So I agree with boldwarrior here

Cycling exercises for athletes that utilize bbuilding principles to build strength is STUPID. Only advanced athletes should cycle Foundation exercises on weekle, bi-monthly and monthy basis to allow going over 90%+ for more time. Others shoud keep the foundation exercises the same, and vary the major auxilary ones. This is covered in my upcoming article at
Too lot of athletes utilize too much of variation (me included) based on bbuilding principles…
These are two different sports… the only common thing for them is the gym. But how one use the gym (means, loads, methods) will dirrect him to his outcome/goal.

None of the above changes the fact that the shape of individual muscle bellies is genetically predetermined. this doesnt mean y ou can achieve a certain look. the reason arnold found it valuable to change excercise grip ect. is because slight variation in training stimuli prevents overtraining and stagnation. same concept used by the boys at westside, ie changing their lifts every couple weeks whiel still hitting the same muscles and movements that are need to perform at a high level in the squat deadlift and bench. once again another indicator that fatigue is largely influenced by inhibitory pathways.

What is “individual muscle bellies”??? When we talk about hams we actually talk about semitendinosus, semimembranosus, biceps femoris. Even if their belleies are genetically predetermined, this doesn’t negate the neccessity for doing specialization work to work on the weak points of your estetical look… thus hitting/improving the different “muscels” within the zone of genetics…

Your example of the hamstrings answers the question Duxx. Biceps- short and long heads. You can transfer more stress on one head by changing exercises. Working the long/outer head gives the illusion of more peak. Working the brachialis pushes up the biceps and gives the illusion of lower biceps development. I do agree that specialization work should be done for weaknesses, but not until a trainee is more advanced. Even most bodybuilders build mass with compound exercises first and then add specialization work for detail (like a sculpture- start with a mass first and then chisel away to get the refined product).

Remember Charlie’s adagio: “If it looks right,it flies right”…
Adequate and careful training will take care of the shaping of the body surely more than the reverse.
Besides if looks play a role in our wide world,I do not see how they would not be of at least some importance in the smaller world of athletics and sport!

Not just motor control - but also physics.
Remember that despite everything we think we know about recruitmtent and fibre types the basic laws of physics still stand and the muscles will recruit themselves in a manner that physcially is most advantageous in terms of levers and force.

This not a cop out but … of course the whole area of partial reps etc. for BBing is mute, considering the better/illegal regeneration methods used and the further they can push their muscles and CNS.
This gives a false reading on the effect or effecaicy of such things as partials or even volume.

but who decides if it looks right. if it were a bodybuilder then sprinters would weigh 300 lbs and their calf size would have to match arm size for proper symetry. if it your notmal fitness junkie its having big arms and chest with twigs for legs.


if your building your hams with the leg curl, then that part of your hammy will build up, and hence, look wrong, and therefore if wont sprint (function) correctly.
if you build you calf’s to 20’" to build massive strength in the calf’s, then the added weight for the follow through will slow things down more than speed things up. So hence, the calf’s will “look” wrong.
If you upper hammys, lower back and gluts are well developed from the correct weight training, then you will “look” like a sprinter and hopefully function more like one on the race track. (Pending many other variables)