-: So, if we look at somebody doing a squat here
and we talk about some of this intrinsic and extrinsic
thing going on, right?
So this guy here he's doing a squat.
Now, he might be thinking about going down.
He might be thinking about driving his knees
forward or butt back but you know what he probably
isn't having to think about?
He's not having to think about where this bar is
in relationship to his feet.
He's not having to think about balance.
He probably isn't really having to think about
left to right that much unless something's really
weird going on with his structure and what not.
So, his brain is subconsciously,
on the extrinsically, it's figuring out,
okay, if I'm squatting down,
the ankle needs to bend this much,
the knee needs to bend this much,
and the hip needs to bend this much
in order for me to stay balanced, right?
And while I'm doing that, I need to fire this much
glute, and this much hamstring, and this much quad
and this much gastroc and whatever to be able
to control all of those joints proportionally,
so when I go down, I manage to make this
the most balanced, the least deficient possible.
So, if you've never squatted before and you go
squat, you might look like a newborn gazelle.
Your body's not sure how much to bend over,
how much does my butt go back, knees go forward
or whatever and then you look at somebody that's
been squatting forever and they just go up and down.
There's no thought to it, right?
Their body has learned how to efficiently do that
movement pattern, right?
And so when they squat, it looks like this pretty
effortless thing and the person that's never squatted
before, it's like they're learning to walk for
the first time and that's kind of what's going on.
So, when we have multiple joints this becomes
more complicated than we have one joint.
The more muscles we have, the more neurologically
complex these motor patterns are and then when
I start applying different intents, right?
So, if I wanna make this more quad dominant,
I'm pushing my knees forward or if I'm making
this more hip dominant and I'm pushing my butt
backwards, now all of a sudden those are
essentially different exercises right?
And those are new motor patterns that I'm having
to learn because now I need to be able
to contract things differently and move
the joints to a different degree as I'm going
this motion so I learned how to do a efficient
hip dominant squat, it's gonna be a whole
different motor pattern than an efficient knee
dominant or quad dominant squat, right?
So, when we look at what's going on
in the muscular level, right, from when we were
talking about these motor patterns.
So there's two things that are happening in terms
of discrepancy with this what and when.
One is, just which muscles when but then
portion is what muscle fibers within each muscle
when, right?
So, within a muscle here, right, so we've got
a bicep, cause that's the only muscle we ever
give an example for apparently.
We have that bicep and it's gonna have a bunch
of these fibers throughout that muscle so if we
take the bicep here and kind of put some fibers
so you could see them, right?
What you'll have is you'll have this alpha motor
neuron that's gonna come and it's gonna branch
out and touch certain of those sarcomeres,
certain of those muscle fibers.
And so those are gonna be the ones
it's responsible for contracting.
So, think of it like you have this string of
cords, if you will, that are running from
your brain all the way to your muscle tissue right?
And so, each of those cords controls a certain
number of fibers within that muscle and what
your body does when it's making a contraction,
is you can't keep contracting the same fiber over
and over and over again throughout a movement.
What you need to do is you need to be able
to contracting grouping A then grouping B
then grouping C so that you can continue movement
through the concentric and eccentric, right,
because otherwise it's like okay, this is
the halfway short fibers and then whatever.
It's like certain fibers would have to stay
contracted all the time and so they would never
get to rest.
So your body has to basically switch what's being
contracted at a microsecond level
throughout the entire ranging motion, right.
So as I'm doing this, right, some things are
contracting, some things are relaxing, right,
but in a concentric it's a net more things
are getting shortened, right, and in eccentric
it's more things are becoming lengthened in terms
of that contraction.
So, for a given movement, a given intent, a given
range of motion, my brain will learn to use
certain of those motor neurons, right?
So at the bottom of a bicep curl, my brain will
have wired a certain set of these motor neurons
to start that exercise and then in the middle,
it'll have another group and at the top it'll
have another group and there may be some overlap
in terms of which fibers are working where,
but what you'll look and especially when you get
into complex muscles like the quadriceps
or hamstrings where we're having multiple heads
of these muscles, right?
Your brain is going to learn when it's doing
these exercises, okay, if I use this part
of the quad here, it does it more efficiently
than this other part of the quad so I'm gonna
use it in this part and let it rest when I get
to a part where a different part of the quad
can work the most right?
And that's gonna be a big part of the advanced
mechanics course that we do in the coaching
certification as kind of getting into okay how do
I optimally load this particular division of
the quad or this particular division of
the hamstring but for the sake of this,
what you really just need to understand is that
our brain also learns how to use certain portions
of a muscle throughout different degrees of range
of motion that you're using and under different
conditions of fatigue or strain or with different
intents applied to the exercise, okay?
So now with our nervous system,
we talked a little bit about the nervous system
when we went over systems in the introductory
content so remember one of the adaptations that
the nervous system gets is it can increase its
storage and its ability to recycle, regenerate,
and deliver ATP and neurotransmitters and they go
together, right, so your body clusters
neurotransmitters and ATP together and that is
what's gonna be released so if we look at that
with a visual, this is a synapse here so we have
kind of like this tear drop looking,
it looks like a sack filled with water,
so to speak right?
That's the end of your nervous system here
meeting the muscular system so this would be
the neuromuscular junction that we have here at
the synapse right?
So, inside this synapse is gonna be these little
vesicles, right, so you see these little circles?
Right, and within them is neurotransmitters bound
with ATP and when you stimulate your nerve,
right, you're gonna get this electrical impulse
that is gonna fly from your brain all the way
down to this synapse, right, and that electrical
impulse is gonna cause calcium to pour in here.
That calcium is going to start a cascade in here
that is going to increase energy production
and push these vesicles to the bottom here
where they're basically gonna do the opposite
of what we were talking about with the satellite
cell donation where it's like a oil droplet
meeting a bigger droplet and opening up.
Here's it's like an oil droplet is getting
to the edge and then it's releasing it's content.
So the vesicle gets to the edge and basically
merges with the outer membrane of the synapse
here and releases the ATP and
the neurotransmitters into the synaptic cleft
where the muscles actually have their receptors
for those neurotransmitters, right?
So once those neurotransmitters enter here,
they are now signaling the muscle to contract,
right, and so the amount of neurotransmitters
that dump out and the rate at which they do,
affects how this muscle's going to contract.
Whether it's going to be a hard contraction,
a light contraction, whether it's gonna be
a fast twitch, slow twitch.
The amount of tissue that's gonna be contracted
is gonna be a bi-product of how much of this has
happened and then how many of these things--
how many of those motor neurons are actually
being stimulated simultaneously, right?
So, that's essentially how our nervous system
gets the muscle to contract.
An important aspect of this, which I'm gonna show
on this other image here, is cell--
Little less fancy graphic here, but we have that
calcium coming in so that calcium doesn't just
say hey, let's release the neurotransmitters
and the ATP.
It's also an important signal cause we have this
mitochondria that exists in the nervous system
as well and so that calcium tells the mitochondria
to start making ATP so that when we need to
recycle those neurotransmitters, we need to be
able to basically reset.
We need to get the neurotransmitters back, right,
which if I go back here, alright, these guys are
emptying out and all this is stuff coming here,
eventually what has to happen is, well those
neurotransmitters can't just stay out there
forever.
We've released them, they do their job, but then
I actually have ways of getting
the neurotransmitter to come back in here, I put
it back in a vessel and I get new ATP with that.
So I repackage the neurotransmitters with ATP
after I've taken them back up into the synapse.
In order to do that, I need to be able to make
ATP right here, locally.
So, one of the adaptations that we get from doing
a lot of neurological work or from taxing this
system is that we actually get the mitochondria
to migrate down towards the synapse so that we
have more mitochondria down here which means
we can make more ATP, which means we can do
higher intensity contractions more frequently.
So we can do, not only just more intensity period,
but we can do that more intensity again sooner
because we can replenish the ATP, right?
So you'll have two limiting factors.
One, how fast can I get the neurotransmitters
back in here and two, how fast can I replenish
the energy because if I don't have ATP to
package with the neurotransmitters, then I can't
restore those vesicles to dump out.
If I dump out the neurotransmitters without
the ATP, they won't actually be able to do
their function in terms of signaling the muscle
cause you need to have the neurotransmitters with
the ATP to actually get that contraction based
effect, right?
So, just like in our muscle cells, we can improve
our mitochondria efficiency and mitochondria
number, we can do the same thing with the nervous
system, right?
Now, in terms of the nervous system's energy,
balance all we have to do is tax this system,
right, so we just have to tax the energy, right?
So, it doesn't necessiarly mean
one RM sets tax the system more
but anytime we're demanding a lot
in terms of contractions, either with intensity,
or volume, or frequency.
All those are gonna improve the energy system
of the-- the energy portion of the nervous system.
Yeah, the energy system of the nervous system but
then the mitochondria within the nervous system,
it's gonna get more metabolically efficient.
That is gonna be different than the extrinsic
adaptations that we get in terms of being to say
contract more muscle fibers at once, right,
or to convince our body to use fast twitch
over slow twitch.
Those are not gonna be the energy based stuff
but this energy based stuff will effect our
performance in all other things, right?
So, if we're fatigued neurologically before we
get a stress in the muscular tissue well then
obviously we're not gonna be able to reach
the stimulus that we wanted whether it's
a metabolic stimulus or a hypertrophy stimulus
or whatever it may be because we couldn't get
the performance that we needed, right?
So having this energy system well trained,
it tends to enhance our abilities for performance.
That being said, once we get a little bit of
conditioning here, we're almost always going to
fatigue muscularly before we fatigue this,
alright, once we start training.