Can You Change The Shape Of Your Muscles?

Summary

In this insightful conversation, Dr. Mike and Dr. Brad Shonfeld explore the concept of regional hypertrophy in muscle growth. They discuss the possibility of differential muscle development within a single muscle head and along the length of a muscle. Dr. Shonfeld, a leading expert in muscle hypertrophy, shares compelling evidence supporting the existence of regional hypertrophy, influenced by factors like eccentric and concentric training. The discussion delves into the practical implications for bodybuilders and fitness enthusiasts, suggesting that targeted training can subtly alter muscle appearance and shape, enhancing the understanding of muscle development for optimized training programs.

Takeaways

• 💪 Regional hypertrophy refers to the growth of specific parts of a muscle, either between different muscle heads or along the length of a muscle.
• 🏋️‍♂️ Muscle fibers do not always span from origin to insertion; some terminate within the fascicle, which can lead to nonuniform muscle growth.
• 🧠 The concept of regional hypertrophy goes against traditional exercise science teachings, which stated that muscles develop uniformly from proximal to distal ends.
• 🔬 Evidence suggests that eccentric training can lead to greater growth at the distal portion of a muscle, while concentric training shows greater growth in the middle.
• 📊 There is compelling evidence supporting the idea that regional hypertrophy can be achieved through different types of training.
• 🤔 The long-term effects and visibility of regional hypertrophy on the macro scale, such as in bodybuilding, are still areas of uncertainty in the literature.
• 🏋️‍♀️ While you cannot change the inherent shape of a muscle (e.g., from flat to peak), you can influence the overall body shape by targeting specific areas of muscle growth.
• 🦿 Medialateral hypertrophy differences within a single muscle head have not been shown, unlike proximodistal differences.
• 🦵 The position of the feet and hands, as well as elbow and knee tracking, can influence which parts of a muscle are emphasized during training.
• 📚 A study in review suggests that single-joint exercises like leg extensions can target specific heads of the quadriceps differently than multi-joint exercises like leg presses.
• 🦶 For the calves, seated calf raises do not selectively target the soleus more than the gastrocnemius, contrary to common belief.

Q & A

What is regional hypertrophy and what does it refer to?

Regional hypertrophy refers to the concept where different parts of a muscle can grow at different rates, either between different muscle heads or along the length of a single muscle. It can also refer to the differential growth in response to specific types of training.

Is there evidence to support the idea of regional hypertrophy along the length of a muscle?

Yes, there is compelling evidence suggesting that regional hypertrophy along the length of a muscle is possible. Studies have shown that certain types of training, such as eccentric training, can lead to greater growth at the distal portion of the muscle.

Can muscle fibers span from origin to insertion in all muscles?

No, not all muscle fibers span from origin to insertion. Many muscles have fibers that terminate intrafascicularly, meaning they do not necessarily span the entire length from one end to the other.

How do different types of training affect regional hypertrophy?

Different types of training, such as eccentric and concentric actions, can have varying effects on regional hypertrophy. Eccentric training has been shown to promote more growth at the distal end of the muscle, while concentric training can lead to more growth in the middle aspect.

What is the magnitude of difference in muscle growth due to regional hypertrophy?

The magnitude of difference in muscle growth due to regional hypertrophy can be significant, with some studies showing more than a 10% difference in growth between different regions of the muscle.

Can regional hypertrophy be observed on a macro scale, like in physiques?

While regional hypertrophy can be observed with tools like ultrasound or MRI, its visibility on a macro scale, such as in physiques, may not be as noticeable unless one looks closely or there is a significant difference.

Can foot and hand positions during exercises affect regional hypertrophy?

Yes, foot and hand positions can influence which parts of the muscle are targeted, potentially leading to regional hypertrophy differences. For example, turning toes in or out during calf raises can emphasize different aspects of the gastrocnemius muscle.

What is the impact of different squat stances on muscle hypertrophy?

Different squat stances, such as a sumo wide stance, can lead to greater activation of certain muscle groups. For instance, a wider stance can work the adductors and glutes to a greater extent compared to a narrower stance.

How does the type of exercise (single joint vs. multi-joint) affect muscle hypertrophy?

Single joint exercises, like leg extensions, can target specific muscle heads more effectively, such as the rectus femoris, while multi-joint exercises, like leg presses, can work on different muscle heads, like the vastus lateralis.

What are the practical implications of understanding regional hypertrophy for muscle training?

Understanding regional hypertrophy allows trainers and athletes to design more targeted training programs that can potentially alter the shape and appearance of muscles, even though the inherent shape given by genetics cannot be changed.

Is there any research on the effectiveness of seated calf raises compared to other calf exercises?

Research suggests that seated calf raises do not selectively target the soleus muscle more than the gastrocnemius, contrary to popular belief. Both muscles experience similar growth with seated calf raises, which is less than what is achieved with straight leg raises.

Outlines

00:00

💪 The Concept of Regional Hypertrophy

In this paragraph, Dr. Mike introduces the concept of regional hypertrophy, a topic of interest in bodybuilding and exercise science. Dr. Brad Shonfeld, an expert in muscle growth, explains that regional hypertrophy can refer to the differential growth between different muscle heads or along the length of a single muscle. He discusses how muscles develop and the myth that they grow uniformly from origin to insertion. Instead, he points out that muscle fibers may terminate intrafascicularly and can be innervated by different nerves, allowing for nonuniform growth. The paragraph sets the stage for a deeper dive into the evidence and implications of regional hypertrophy in muscle training.

05:00

🔍 Analyzing Regional Hypertrophy Evidence

This paragraph delves into the current state of evidence regarding regional hypertrophy. Dr. Shonfeld clarifies that while there is clear evidence of differential growth between muscle heads, the concept of growth along the length of a muscle is more nuanced. He cites research showing that eccentric training may promote greater growth at the distal end of a muscle, while concentric training affects the middle more. The discussion highlights the potential for different training methods to influence the distribution of muscle growth, suggesting that targeted training could lead to noticeable differences in muscle appearance.

10:01

🤔 The Impact of Regional Hypertrophy on Muscle Shape

The conversation explores the practical implications of regional hypertrophy, specifically whether it can significantly alter the shape of muscles on a macro scale. Dr. Shonfeld discusses the use of ultrasound and MRI to measure muscle growth and acknowledges that while some differences in muscle growth can be quite large, the overall shape of a muscle is largely determined by genetics. However, he suggests that targeted training could lead to subtle yet noticeable changes in muscle appearance over time, providing a qualitative impact on one's physique.

15:02

🏋️‍♂️ Training Techniques for Targeted Hypertrophy

In this paragraph, the focus shifts to how specific training techniques might influence regional hypertrophy. The discussion includes the impact of foot and hand positions, as well as elbow and knee tracking during exercises. Dr. Shonfeld references a study showing that turning toes in or out can affect the lateral or medial aspects of the gastrocnemius muscle. He also mentions unpublished research indicating that single-joint exercises like leg extensions can target specific heads of the quadriceps differently than multi-joint exercises like leg presses. The paragraph concludes with a humorous note on the ineffectiveness of seated calf raises for targeted growth, suggesting alternative exercises for better results.

👋 Conclusion and Future Discussions

The final paragraph serves as a conclusion to the video script, with a brief mention of future discussions on topics such as grunting during exercise, which Dr. Shonfeld humorously admits is outside his area of expertise. The paragraph wraps up the conversation on regional hypertrophy and its implications for exercise programming and muscle development, leaving viewers with a sense of anticipation for further insights in subsequent videos.

Keywords

💡Regional Hypertrophy

Regional hypertrophy refers to the concept of selectively growing different parts of a muscle, rather than the muscle as a whole. In the video, it is discussed as a phenomenon that can occur between different muscle heads or along the length of a muscle. The script mentions that muscles can develop differentially, which is contrary to traditional beliefs, and this concept is central to understanding muscle growth and training strategies.

💡Muscle Fibers

Muscle fibers are the individual thread-like structures within muscles that contract to produce movement. The script explains that not all muscle fibers span from origin to insertion, and some terminate within the muscle belly, which can contribute to regional hypertrophy. This concept is important for understanding how muscles can grow in a non-uniform fashion.

💡Eccentric Training

Eccentric training involves lengthening the muscle while under tension, typically the lowering phase of an exercise. The script suggests that eccentric training can lead to greater muscle growth at the distal portion of the muscle. This form of training is highlighted as a method to potentially influence regional hypertrophy.

💡Concentric Training

Concentric training is the phase of an exercise where the muscle shortens, usually the lifting phase. The video script contrasts eccentric and concentric actions, noting that concentric training tends to show greater growth in the middle aspect of the muscle. Understanding the differences between these training types is key to manipulating muscle growth patterns.

💡Proximal and Distal

Proximal refers to the part of a structure that is closest to the point of attachment, while distal refers to the part that is farthest from the point of attachment. In the context of the video, these terms are used to describe where along the length of a muscle hypertrophy may occur. The script discusses evidence suggesting that different types of training can affect these regions differently.

💡Muscle Insertion

Muscle insertion is the point where a muscle attaches to a bone. The script explains that some muscle fibers terminate before reaching the muscle's insertion, which can affect how the muscle grows and is trained. This concept is crucial for understanding the mechanics of regional hypertrophy.

💡Neurological Control

Neurological control refers to how the nervous system activates and regulates muscle contractions. The video script mentions that different regions of a muscle can be innervated by different nerves, which may allow for regional hypertrophy. This concept is important for understanding the selective growth of muscle regions.

💡Biomechanics

Biomechanics is the study of the mechanical laws relating to the movement or structure of living organisms. The script uses biomechanical inference to explain how certain exercises can target specific parts of a muscle, such as turning toes in or out during calf raises to target different muscle heads.

💡Quadriceps

The quadriceps, or quads, are a group of four muscles at the front of the thigh. The script discusses how different exercises can lead to differential hypertrophy within the quads, such as leg press versus leg extension. This is an example of how regional hypertrophy can be applied to specific muscle groups.

💡Gastrocnemius

The gastrocnemius is one of the two main muscles in the calf. The video script discusses how different types of calf raises can affect the growth of the gastrocnemius and soleus muscles differently. This illustrates the concept of regional hypertrophy within a single muscle.

💡Exercise Variation

Exercise variation refers to changing the way an exercise is performed, such as altering foot or hand positions, to target different muscle groups or regions. The script mentions how variations like narrow or wide stances in leg presses can affect which parts of the quads are targeted, demonstrating the practical application of regional hypertrophy principles.

Highlights

Regional hypertrophy can be the hypertrophy between different heads of a given muscle or differences along the length of a given muscle.

Muscles develop not strictly from proximal to distal end, contradicting traditional exercise science teachings.

Certain muscle fibers terminate intrafascicularly, not necessarily spanning from origin to insertion, and are innervated by different nerves, allowing for nonuniform hypertrophy.

Eccentric training has been shown to promote greater growth at the distal portion of muscles compared to concentric training.

Concentric actions display greater growth in the middle aspect of muscles, highlighting the impact of different training types on regional hypertrophy.

Regional hypertrophy can be observed and measured using ultrasound or MRI, identifying variations in muscle growth along its length.

The magnitude of regional hypertrophy differences can be significant, with some studies showing more than a 10% difference in muscle growth.

While regional hypertrophy can influence muscle shape, it cannot change the inherent shape determined by genetics.

Regional hypertrophy provides options for exercise programming to subtly change muscle appearance and physique.

Medial/lateral hypertrophy differences within a single muscle head have not been shown, unlike proximodistal differences.

Foot and hand positions, as well as elbow and knee tracking, can influence hypertrophy in different muscle heads.

Turning toes in during calf raises works the lateral gastrocnemius more, while turning out targets the medial aspect.

Quadriceps respond differently to single-joint leg extensions versus multi-joint leg presses, indicating targeted hypertrophy potential.

Seated calf raises do not selectively work the soleus more than the gastrocnemius, contrary to common belief.

Both the gastrocnemius and soleus experience less growth with seated calf raises compared to straight leg raises.

The practical application of regional hypertrophy in exercise programming offers a nuanced approach to physique development.

Research on grunting's impact on hypertrophy is lacking, but its role in exercise performance is noted humorously.

Transcripts

we can have like the Bro Science do

concentration CS at works the peak of

your bicep that somehow you're going to

make like a flat bicep into a

mountainous bicep and you can't change

the inherent quote unquote shape of a

muscle hey folks Dr Mike here with a

even more important Dr Brad shanfeld now

I know some things about muscle

hypertrophy but I learned most of them

from Dr shonfeld Who is the world's

ranking expert on muscle growth crazy I

know but really a thing you can have

nowadays I'm here to ask Dr shf a

different question and all the questions

I have to ask are about Regional

hypertrophy first what the hell is

regional hypertrophy before you tell us

if it really happens or to what extent

what is it yeah so it really can be one

of two things it can either be the um

hypertrophy between different heads of a

given muscle so like your shoulders of

an anterior middle and posterior head

the quad STS you have your rectus

femoris vas lateralis Etc so it could be

different differential effects between

the muscles themselves or and this is to

me really interesting because it goes

against what I was taught when I was

first coming up same it can be

differences along the length of a given

muscle let's say like the vastus

lateralis um so when I was an upand

cominging excise science student

somewhat long ago now um we were always

taught that muscles develop along the F

from from insertion to uh to from

proximal to distal end original

insertion and um that actually is been

shown not to be the case and it's quite

interesting that muscles some of the

interesting things are that muscles uh

certain muscles many of them terminate

the actual fibers terminate

intrafascicular So within the fasle they

don't necessarily span from origin to

insertion they actually are terminating

before the end or or to from the middle

to the distal portion and some of these

fibers or some of these regions are

innovated by different nerves so which

gives again more Credence to an ability

for these muscles to hypertrophy in a

nonuniform fashion y so basically to uh

un science that really quick some of our

viewers are just not that smart I'm one

of them so let me explain this in D

Jango block fashion um a muscle whole

muscle let's say muscle fiber and muscle

cell is the same thing

so a lot of people think like every

muscle fiber goes from all the way top

to bottom and in some muscles that's

true I think in the sorus you got some

muscle cells that are insanely long but

in a lot of muscle F in a lot of whole

muscles one muscle cell will go to here

another one will go to here another here

and they're even activated by different

nerves so hypothetically you could at

least see some Regional differences

where one part of the muscle grows more

from maybe one exercise or one angle or

XYZ we'll get to that in a sec and

another part of the muscle gross from

other so that's the idea of regional

hypertrophy absolutely super um the

state of the evidence currently on

Regional hypertrophy what is your

analysis yeah so it's uh quite clear now

probably not news to most people that

you can get different uh growth in

different heads although in certain

respects there is some interesting

information we could talk about as far

as that goes but um as far as the

regional along the length of a muscle

there's now in my opinion from my uh

knowledge of the literature quite

compelling evidence I would say that you

can get Regional hypertrophy and what's

really interesting it can be initiated

by different types of training so let's

give you some examples Ecentric training

uh has been shown so when you're

comparing Ecentric which is the

lengthening portion for those who know

you're lengthening versus a concentric

where you're uh Contracting quot

Contracting shortening muscle um

the Ecentric action has been shown at

least in some St uh some research to

have greater growth at the distal

portion of the muscle whereas the uh

concentric action shows greater growth

in the middle aspect of the muscle uh so

again somewhat interesting uh lengthen

partials becoming a big Topic in

training now and programming um

similarly that uh the lengthening aspect

seems to show its biggest effects

distally that you're getting the

greatest disparity

between let's say a lengthen partial

versus a shorten partial uh at the

distal end and that it becomes less even

though there most studies seem to show

across the muscle but the magnitude of

the effect is most prominent D

interesting very interesting this is a

big big question I have for you very few

people know the answer I don't even know

the answer I have my suspicions what is

the relative effect magnitude of

regional hypertrophy

is it something that we can see on the

macro scale like can you look at

physiques and let's say we had a ton of

identical twins that were oh let's say

for hypothetical purposes living in a

Truman showes environment where they

thought they were in the real world but

they never were we just bred them

exclusively to study muscle things they

thought they went to school turns out

nothing even happened the robot

professors they're all fake but they

train in different ways some of them

train exclusively in ways that we think

will grow distal parts of the muscle

others train exclusively in ways that

will grow proximal parts of the muscle

is it one of these things that in the

literature under uh analysis with deep

methods like ultrasound that we can see

their fiber differences but on the grand

scale zoomed out you can't really quite

tell is it nuanced you can tell but you

got to look really hard or is it like

these are real legit you can change

something like the shape of your muscle

kind of differences yeah so the

magnitude we generally looking at either

ultrasound or MRI to we're not looking

at the actual fibers we're looking at

the whole muscle the whole muscle like

we're looking at slices along the length

of the muscle and the magnitude in some

of the sodi is quite large I mean some

it's more than 10% difference more than

10% some dou it's not

100% well uh

so depends how you're what your metric

is so let's say if you're talking about

the difference between 10% versus 20% is

that 100% or is that a 10% difference so

I'm looking at that as a 10% difference

like on a Rel it's relative matter you

can look at it it's double double the

growth so if we have 10 units of muscle

size and we go through a 12-week

training period one uh of the comparator

conditions grows to 11 units and the

other grows to 12 units corre that to

you would be a 20% 10 a 10% difference

there roughly 10% was never my no for

sure was that 10% is to you or 100% is

to you no that's that would 10 so one is

10% the other is 20% so that would be a

10% difference but you could say

depending upon how you're looking at it

uh now again how does that manifest over

time so yeah that's just in a short

period of time is that 10% or 100 even

double that uh noticeable in that

shorter period of time or will that

manifest over longer periods does it

take six months to really become a

parent but the question that becomes

will you continue to see the gains in

real we these These are gaps in the

literature I would just say that we

don't know and the fact that um you're

seeing I think a magnitude of difference

that is quite in my opinion quite uh

influential that it would be a I think

you'd be um you'd be misguided not to

take that as something that you'd want

to

explore and so is it tenable as

hypothetical to say something like look

Regional hypertrophy differences based

on different kinds of training let's say

highly concentric emphasis versus highly

Ecentric emphasis now most training is

dynamic and trains

gr um if that difference presents itself

as we've seen it in literature over the

long term is it safe to say like look no

it won't radically change the shape of

your muscle as seen from external

perspective like on a Instagram photo

but subtly it can change it in such a

way that the overall visual picture like

D dude your biceps do look a little bit

kind of longer not like you

turned under Ronnie Coleman from having

total flat biceps but something that

over time can definitely have a

qualitative impact on physique is that

are you comfortable hypothesizing that

yes so I think we need to be careful at

least to clarify when we talk about

changing the shape of a muscle um

there's several connotations to that so

I we can have like the Bro Science do

concentration CS that works the peak of

your bicep that somehow you're going to

make like a flat bicep into a

mountainous bicep and you can't change

the inherent quote unquote shape of a

muscle if your muscle is going to be

rounded rather than Peak quote unquote

you can't tot do an exercise that will

Peak it so Arnold Schwarzenegger had

that wasn't the the training that he did

that gave him that Peak that was his

bicep that was his genetics but you can

change the shape of your body if you

will by making more getting more

hypertrophy in aspects in certain

aspects as opposed to others and I think

that certainly is a uh a reasonable and

a rational way to go go about saying it

I'd also point out that when we're

talking about this type of thing um if

you're going to do let's say from a

practical standpoint if you're going to

do uh a program that involves just

concentric actions you may benefit let's

say from having some Ecentric overload

training involved to Target quote

unquote Target the disto aspect of the

muscle so it gives I think options for

from a programming standpoint to allow

you to quote unquote change the shape of

your body yes we already know based on

your answer so far two things I want to

ask if thing number three is a

possibility we know that you can and

we'll get to a bigger expansion this

question a sec we can grow

differentially you can stimulate

different heads of a muscle distinct

concrete regions we also know the

proximodistal uh Regional hypertrophy is

definitely a thing what about

medialateral hypertrophy differences

within a single uh head of the muscle so

if I say have my like vasus lateralis is

it possible uh hypothetically to grow

more of the outside of it versus the

inside in the single given head or has

it just not been Illustrated of the vast

never been shown never been shown has it

never been shown like we've analyzed it

and it it doesn't happen or we've just

never tried never been and trying to

look at the pieces like the generally

you're looking at slices that are going

this way so trying to go to the outside

versus inside and it's best lateralis is

a relatively thin muscle it's not what I

think that would be difficult to look at

sure okay and uh this is a real real

real practical

question in the real

world do foot and hand positions and

let's say elbow and knee

tracking do they make a difference in

hypertrophy head by head so the ultimate

example of this is if I take a narrow

stance in my leg press and have my knees

Point relatively straight is that going

to grow the outside of my quad more than

if I take a wide stance and point my

knees really far out is that going to

grow more of the inside of my quad or is

the quad a real bad example because all

the heads kind of work in Synergy maybe

there are other muscles that are better

examples of that so a couple things

um that has not been shown for the quas

there is some evidence it's limited but

it's certainly one study in particular

did show that turning your in calf

raises now I know you don't care about

the Cales but you got the Jack Cavs

already I do put in the work um but

turning your toes in tends to work the

lateral aspect of the gastric nemus

while turning your toes out tends to

work the medal aspect and that's how

biomechanical inference would agree so

thank God it's not like totally bonkers

the other way around uh so there is some

evidence in the Cavs of that not in the

uh in the quads there is evidence that

if you take like more of a sumo wide

stance and squats it's going to work the

adductors to a greater extent to some

extent depends on the inclination High

bar versus low bar but your glutes as

well but as far as the quads know but uh

that now that you brought it up I'll

give you another scoop our group has a

our lab has a study that's in review it

should be hopefully published soon uh

where we looked at the quadriceps we

actually looked at the quads on the

calves um we looked at the quads doing a

leg press so and this was within subject

so one group did a leg press the other

leg did a leg extension the leg press

worked more the vasus lateralis the leg

extension worked more in the rectus Fus

so basically you're getting you can look

at targeting hypertrophy in the given

heads of the quads by doing single joint

uh knee extension versus multi-joint uh

knee hip

extension uh and for the calves

interestingly it' always been taught

that seated uh calf raisers work the

Solus because you're going to make the

gasr actively insufficient and your

straight leg work more the gastrock

straight leg does work more the gastrock

the seated did not really work more of

the uh Solus the gastra got pretty much

just as much growth from the seed is

from the the the Solus got as much sius

got the same in the from the same so the

gastro suffered in the SE gastr did not

suffer in the seated Gast I'm sorry they

both were less but they it was not to a

correct that you need to so correct you

the gastro did not suffer more than the

Soviet like you got similar but both

were less than the UMES than the

straight leg so basically seated calf

raises suck like I had suspected for

forever they were not they are not

obligatory yes but there are two

advantages of them one is first of all

almost all the machines look like double

dildo handles that you have which is

cool practice for day job another one is

you can put a lot of plates on a seated

calf how are you supposed to impress the

ladies if not with a lot of plates and

grunting of course good point do you

have any research on grunting that we

can talk about do not ah folks this has

been Dr Brad shonfeld he knows a lot

about actual hypertrophy his grunting

expertise is limited next time we'll ask

you about grunting I'm going to

personally fund 17 independent grunting

studies I'm looking forward to that

excellent see you guys next time