What's up Champ! I'm Vince Del Monte of GeneExpressionTraining.com. In this
video we are going to start a brand new series called "The Truth About." And we are
going to explore some of the what may be called some of the more "controversial"
exercises. In today's video we are going to look at the truth about leg
extensions. We are going to uncover a lot of myths. We're going to look at is it
good? Is it bad? Is it better is it worse? What are the pros what are the cons? When
should you do it? When should you do not do it? How do we do it? And we're going to find
out if this is an exercise you want to keep in your program alright. This video is
going to be very eye-opening. Very different than anything you've heard before
so let's get into it.
So before we dive into the leg extension we need to understand
the three different types of force that we can create within our joints. This can all
be found in any biomechanics textbook if you'd like to learn more. Don't ask me is
there a study to support this. This is all basic biomechanics guys so the first
of three are what's called compression. The second is called distraction and the
third is called shear. Alright. So when we're training in the gym, compression is
when we add a barbell to our back and all the joints underneath that load are
being compressed. So when you're doing a back squat, all your spinal muscles are
being compressed. That's compression alright. When we're
doing a pull-up, that's called distraction. That's when your joints are
getting pulled apart and the only thing keeping you together are your ligaments
and your muscles contracting to keep your body together. The third type of
force is called shear. Alright. Shear is when we have two joint
move around each other. Now shear is a term that people hear and they get
freaked out about. Shear is natural. It happens in every single shoulder joint
sorry every single joint in your body. Your shoulders, your hips, your knees, your
ankles. Alright, it's a natural thing alright. So when you hear people talk about oh
don't do the leg extension it creates shear in your knees, every single shoulder
exercise creates more shear in your shoulders than the leg extension creates
shear in your knees. So if you're afraid of "shear" from leg extensions, that even
goes for leg curls too then stop doing all shoulder
exercises today because there's far more risk with those ones than with the stuff
down there alright. So that's the first thing we want to learn about
the leg extension. There's nothing wrong with the leg extension because it's a natural
joint motion alright. So that's take home number one. So now that you know
that shear is not unique to any single joint in the body, it's a natural joint
motion, it's the natural rubbing against joints when two joints are moving in
opposite directions we don't have to be afraid of sitting on a leg extension. Now
let's look at this exercise in context to goals alright. Let's talk about
building muscle alright. We're going to compare two exercises. Leg extension and
squats. You saw this coming right. So barbell squats. We've got load on our back
but when we're standing there with the load on our back is it hard?
Is there any challenge to the stuff at the front of our lip above our leg,
the quads. You got load on your back. Is this hard? No. You could probably stand
here for quite a while. Alright. When does it become hard? It becomes
hard when we start creating what's called torque. We start moving our hips backwards.
We start flexing our knees. Alright. The more your hips go back, the more your
knees start to fold up that's when the weight becomes heavy alright.
So when's a squat hard? It's hard a little bit in the middle so a lot of you
guys could, you know, take 3-4 plates and if I told you to go down a quarter
you could probably hang out there because there's not maximum torque. Now
when we go down to halfway and as they create an isometric contraction here
you're like oh, this is a little harder, when does it become maximally hard? In the bottom
position. Alright. Now if the weight's the heaviest it's in the bottom position and
that's when your muscles are the weakest are you going to get a strong
contraction from your quads? Probably not Alright. It's called the principle of
inappropriately increasing resistance so as your muscles are getting shorter
they're getting weaker but the loads getting heavier. So how can you create a
forceful contraction in your quads when your muscles are weakest and the weights
the heaviest? So you're in the bottom position, the loads
the heaviest, are you hanging out down here? No. You're getting out of that
position as fast as possible. So if our goal is to build muscle tissue, the squat,
while it has benefit, it's not the best quad builder. Try it now. Let's look at
the leg extension. I'm going to sit right over here. So what's cool about the
leg extension machine we can create what's called stability all right we can
now focus on what we want to challenge so if we want to build bigger legs we
want to eliminate ways to make it easier. With a leg extension one of the cool
things we can do is we can create an isometric contraction at every point of
the range of motion. I can create a lot of tension on my quads just with this
partial range of movement a lot more tension than I could create with a
partial range of movement on a barbell squat. If I'm coming up to half way and I
just asked you to hold this and contract this is very very hard. Your muscles are
going to be working because you can't borrow any help from any other joint
systems or any other muscles. So what's going to produce more muscle? Something
that's easier or something that's harder? If your goal is to build muscle we need
to make it hard. If we take this up to 90 degrees and I say hold this for 10
seconds is this hard? This is very hard. You can even see in the demo here I'm
starting to kind of shake a little bit. my muscles are working so one of the big
benefits of the leg extension is that we can isolate this muscle. We can create
massive amount of fatigue without borrowing other muscles. Is that a smart
way to build a muscle? Absolutely. So stop saying barbell squats are better than leg
extensions. While barbell squats are certain a very valuable exercise they
will not create as much fatigue in your quads as the leg extension will and you
can feel it for yourself. When was the last time your legs quivered at the end
of a heavy squat workout. versus a really heavy leg extension
workout. Not the same right. You'll be tired but you're not your quads will
never be the limiting link on a squat workout and if you're trying to take
your quads to exhaustion to build them that's what you have to do. So people
that tell you all you do is compound exercises to build a body
part they got it all wrong. I'm not saying there's not value but if
the context is building muscle tissue, there's a lot of problems as we just
looked at. Now I do want to talk about one problem with the leg extension and
it's how you get to the end range. Alright.
Nobody talks about this. If two cars we're driving on the road and they
bumped into each other like this at maybe five miles per hour, we're going
to have much damage? Probably not. But if we have two cars flying 100 miles per hour
and they crash into each other what happens? People get hurt. So the only
issue I have with leg extension is how you get into the end range all right.
So this is the problem. Lack of control. and end ranges when we're not
considering all the inertial components. Alright. So the problem with leg
extensions is when people use terminal velocity into the end ranges. If you're
moving into the end ranges with control there's no problem at all. It goes back
to our really simple message. Go slower. Control the weight. This stuff isn't
complicated guys. People just want to make it complicated because they're
running out of content to talk about on their channel. We're just trying to keep
this simple guys. This is a no-nonsense Channel. Last thing. There are a few other
considerations with the leg extension. It's never the exercise itself. This is a
hinge joint. This is a natural movement for your knee. The problem is
when we don't set up the exercise properly. So I'll show you the big mistake.
The big mistake is when we don't keep these joints in alignment. The humerus
and the upper leg and the lower leg. Let's just use simple terms. Upper leg or lower
leg. So how do we know if these are lined up properly? Very simple. Our knees are
facing the ceiling aright. So look down at your kneecaps. If your kneecaps
are facing the ceiling, that means you've got neutral alignment of your hips and
you're going to have maximal contraction on your quads once your knees turn out
like this that's when we start getting issues in the knee joint. Again, it's not
what you do, it's how you do it. That's why you've got to avoid people on the
internet who use these like absolute terms
like the worst exercise, the worst exercise ever, the best exercise, because
this is just click bait. Just trying to get your attention all right. We know that
there's nothing wrong with this. This is a natural joint motion. Look this is. This
is not natural. When we've got external rotation at the hips and then we've got
external rotation at the knee now we have unnatural joint forces going
through the knee. You see that. But when this is all lined up
that's all quads. You grab the handles you pull your ass into the seat and you
go to town. Don't crash into the end point.
Don't waste ends. We talked about this in other videos and squeeze the muscle like
it owes you money. If your muscles are moving the joints
are fine guys. The problem is when you start losing control. Simple concept, eh.
So start teaching your friend there's nothing wrong with the leg extension.
Tell them to watch this video. Tell them to line it up properly. Tell
them to initiate the work the movement with the working muscle. Tell
them to own the movement. Tell them to drop the weight. Tell them to control the
ends. If your goal is muscle tissue the leg extension is a fantastic exercise. You
will never get hurt doing a leg extension if you do it with control. The
only challenges occur when you start losing control, joint systems are
crashing into each other. It's a very simple message guys. Are we getting through yet?
Last thing I want to say something I'm very aware of but we don't have time
this will require another video but there's a lot of different kind of leg
extension machines. They all they don't all have the same resistance profile
alright because of the way the cam is set up alright. So that's another topic
for another day let's just leave it at that. Make sure you are aware that these
not all leg extension machines are created the same. I'm fully aware of that.
Again we don't have time to dive into that today. If you'd like me to do that
in an upcoming video let me know and also let me know what other exercises do
you want to look at the pros and cons of is that a friend is it a foe and you're
probably going to find the answer always comes down to it depends on how we do it.
Alright. So we're going to look at the leg press we can look at chest flies we
can look at upright rows. There are certain exercises that have more
issues than others but let's look at it together. I'll be honest I don't have
time to watch everyone's YouTube video alright. I seriously don't okay. I've got
two kids a business I got a family. I like having a life. I don't have time to
watch all the information out there so if you can do me a favor and say Vince
there's a guy on the internet who says this about this exercise what do you
think of that and let's have a conversation in a positive manner like
that, this channels here to help everybody. I'm not here to put anyone
down. I'm learning myself. Let's learn together. Let's do this in a mature way
wouldn't you agree. Alright thanks for watching guys. Last
thing here if you need a resource for learning how to do all your movements
properly MassMechanics.com If you haven't
invested into it do it now. It'll teach you how to execute all your movements.
The proper cues to build muscle tissue. MassMechanics.com
Link somewhere up here or in the description box below. I'll see you guys next time.
Thank you for sharing this video. Thank you for liking this video. I appreciate
when you hit that like button tells me that we're getting something out of this
together. Take care.