Welcome to the huberman live podcast where we discuss science and science based tools for everyday life. I'm Andrew huberman. And I'm a professor of neurobiology and Ophthalmology at Stanford school of medicine.
Today, we are going to discuss the science and practice of flexibility and stretching flexibility and stretching our topics that I believe, do not receive nearly as much
attention as they deserve
for most people, the topics of flexibility and stretching bring to mind things like yoga.
Injury prevention or maybe even contortionism, but
it turns out that flexibility and stretching are features that are built into
our basic body plan,
young children, young animals, and adults, and
indeed, older children, and animals, all stretch, and all have some degree of flexibility. It
turns out that having flexibility and our ability to stretch and the
interaction between stretching and
flexibility, are fundamental to how we move. Our ability to learn
new movements,
Indeed also to prevent injury Will Repair injuries
and to offsetting and reducing inflammation throughout the body. In fact, today I'm going to share with you a remarkable set of studies that show that stretching can actually adjust things like tumor growth. This is work,
that was done by one of the major directors of the National Institutes of Health.
So today's discussion will start with a description of the mechanisms, literally, the cells and the connections from your nervous system that mediate
flexibility and stretching. And I promise that I'll make
Make that information accessible to you, whether or not you have a biology background or
not. Then with that information in hand, I'm going to present to you what the scientific literature says about the best times and
ways to stretch
everything right down to the detail of how long to hold a
stretch whether or not to hold a stretch at all. Because it turns out there are multiple kinds of stretching. So you can imagine you have stretches where
you hold the stretch for a very long time and use as little momentum as possible.
And then there's also what's called Dynamic and ballistic stretching where you're literally swinging your limbs.
To increase the range of motion. I will explain the science and application of flexibility and stretching in the context of
sports performance,
whether or not you're engaging in cardiovascular exercise or resistance, exercise, or both whether or not you're competitive athlete or simply a recreational
exerciser, as I am whether or not you are trying to increase your range of motion and flexibility for longevity purposes or whether or not you're trying to do it in order to
access different parts of your nervous system because we will
soon learn today that your ability to
improve
flexibility and deed to engage in specific stretching.
Exercises can
actually be used to powerfully modulate, your ability to tolerate pain, both emotional and physical pain. So this
thing that we call flexibility and stretching is actually a vast landscape, we're going to simplify and organize all that for you today. And by the end of today's episode, you're going to have a number of simple easy to apply tools that are grounded in the best
scientific research that you can apply for your specific goals before we begin. I'd like to emphasize that
This podcast is separate from my teaching and research roles at Stanford. It is however, part of my desire and effort to bring zero cost to Consumer information about science and science related tools to the general public in
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Canada, and the United Kingdom. Again, that's eight sleep.com huberman to save $150 at checkout. Let's talk about flexibility and stretching. Before we
talk about the
practices of flexibility and stretching, like to just highlight,
Highlight some of the features that are already built into your nervous system and into your body that allow you to be flexible. Some of us, feel tighter than others, sometimes in specific limbs or areas of our
body. Some people feel really loose and limber. Some people even have what's called a hyper flexibility.
I, for instance, have a relative that can take her fingers
and bend them back to the point where they touch her wrist
and it always, you know, makes me cringe a little bit, but she can do that without any pain. She seems to have some hyper flexibility in her joints. I do.
Not have that feature. Some of you may find that you are more flexible than others,
naturally. And some of you might be thinking,
you don't need to build in additional flexibility.
Well, I think, by the end of today's episode, you'll realize that almost all of us can benefit from having some sort of
understanding about flexibility and having some stretching protocol that we incorporate into our life,
if not just for physical
performance reasons, and for postural reasons than also for
cognitive.
And mental reasons.
I'll be sure to clarify what all of that means.
Right now, I'd like to take a moment and
just highlight the flexibility that you already have.
For instance, if you were to move
your arm behind your torso a little bit and then sort
of let go or
stop exerting any effort in doing that.
You would find that the limb would return more or
less to a position next to your torso least, I would hope. So, why is that? Well, it
turns out that there are aspects of your nervous system
aspects of your skeletal system.
Aspects of your muscles
and aspects of the connective tissue that binds all
of that together.
That try and restore a particular order
or position to your limbs and your limbs relative to one another.
So that reflects a very specific set of processes that it turns out are the same set of
processes that
you use when you are trying to enhance
flexibility and stretching.
So I like to just take a moment and review the basic elements of nervous system.
Muscle connective tissue and skeletal tissue bone that allow for
flexibility and stretching
and here we can point to two major mechanisms by which your nervous system neurons. Meaning nerve cells communicate with muscles and those muscles communicate back to your nervous system. To make sure that your limbs don't stretch too far. They don't move
too far such that you get injured.
And in addition to that mechanisms, that Ensure
That you don't overload, your muscles too much
with weight or with tension or with effort and damage them that way because it
turns out that the second
security mechanism of making sure that you don't
overload muscles can be leveraged toward increasing your flexibility almost immediately.
That's right. There are
protocols and tools that I'll share with you that are going to
allow you to vastly improve your flexibility over time. But there are also mechanisms that allow you to quite significantly increase your degree of
flexibility in a very short period of time in within just a few seconds.
So let's establish some of the basic
biological mechanisms in time. We talked about biology or physiology, we're going to talk about structure, meaning the cells, and their connections and functions what they do. They're just a few names to understand. You do not have to memorize these names.
The important thing that I'd like you to know is that flexibility and the process of stretching and getting more flexible involves
three major components, neural me.
Being of the nervous system muscular muscles and connective tissue.
Connective tissue is the stuff that
surrounds the neural stuff and the muscular stuff. Although it's all kind of weave together and braided together in complicated ways. Some of you may have heard of faccia. We're
going to talk a little bit about fashion today. Although
it's such an interesting tissue, that's really deserving of its own
episode fascial tissue. We're going to talk about some of the stuff that surrounds muscles that really gives you your shape and holds everything together and allows
for
This ability to occur. So
here's a key thing that everyone should know whether or not you're talking
about flexibility or not
your nervous system controls your
muscles, it's what gets your muscles to contract. So, within your spinal cord, you have a category of neurons nerve cells that are called motor neurons to be precise. They are lower motor neurons because they're in your spinal cord, we call them lower to distinguish them from the motor neurons that are in your brain up in your
skull.
Those lower motor neurons
Hereafter, I'll just refer to them as motor neurons. If I want to talk about the other kind of motor neurons, I'll say upper motor neuron. So if I say motor neurons, I just mean the ones in your spinal cord,
those motor neurons send a little wire or set of
wires out to your muscles and that creates what's called a neuromuscular Junction, which just means that the neurons meet the muscles at a particular place, those neurons release a chemical. That chemical is called
acetylcholine.
Some of you may have heard
About acetylcholine before. Acetylcholine
also exists in your brain and does other things in your brain.
Mainly it's involved in focus and attention, but at the
neuromuscular Junction, the release of acetylcholine from these nerve cells. These neurons on to the muscles causes the muscles
to contract. When muscles contract, they are
able to move limbs by way of changing the length of the muscle, adjusting the function of connective tissue, like
And ligaments. And for instance, if you're bringing your wrist closer to your shoulder that biceps muscle is Contracting. It's getting shorter. I
mean in reality it hasn't gotten shorter overall, it's just temporarily shorter. Of course
all of that is
controlled by neurons and it's those motor neurons from the spinal
cord that are really
responsible for the major movement of your limbs by way of causing contraction of specific muscles at specific times. So the
key thing to take away is that
Controls the contraction of muscles. Now within the muscles themselves. There are nerve
connections. And
these are nerve connections that arise from a different set of
neurons. In the spinal cord that we call Sensory neurons.
The sensory neurons exist in a different part of the spinal cord and they send a low wire or set of wires into the muscles. And there's a particular kind of sensory neuron that comes out of your spinal cord and into your muscles, which are called
Indle
neurons, they create or they actually
wrap around muscle
fibers and of Corkscrew around them and give kind of a
spring-like appearance if for you afficionados out there. These are intrafusal connections or neurons intrafusal means within the muscle but you
really don't need to know that unless you're really curious about it or you're going to become a neuroscientist or your medical school or something these
spindle
Connections within the muscle that wrap around the muscle fibers sense, the stretch of those
muscle fibers.
So, now we have two parts to the
system that I've described you've got motor neurons. That can cause muscles to contract and shorten
and we have these spindles within the muscles themselves
that wrap around the
muscle fibers. And that information is sent from the
muscle back to the spinal cord,
it's a form of sensing, what's going
on in the
Muscle much in the same way that you have neurons in your
eye that sense light in your external environment, you have neurons in your ear that
sense sound waves in your external environment. You have neurons in your spinal cord that are sensory neurons that are sensing the amount of stretch in the muscles. What happens is if a given muscle is stretching really far those sensory neurons. Those spindles within the muscle will activate and we'll send a
Technical potential, literally a bit of electricity. Along that wires length into the spinal cord, and then within the spinal cord, that sensory neuron communicates through a series of intermediate steps, but to the motor neuron and make sure that that motor neuron contracts.
Now, why would that be useful? Well,
what this does is it creates a situation where if a muscle is,
or is stretching too much, because the range of motion of a limb is increased too much.
Then the muscle will contract to bring that limb range of motion into a
safe range again. Now what determines whether or not a range of motion is quote unquote, safe or not is dictated by a number of things.
It's dictated by things that are happening in this kind of loop of neural Connections, in the spinal cord and muscle. It's also determined by what's going on in your head. Literally in your mind cognitively about whether or not the movement of that limb, it's
increasing range of motion is good for you
whether or not you're doing it.
Deliberately whether or not, it's bad for you. And then there are also some basic safety mechanisms that are put in there. That really try and restrict our
limb range of motion.
Okay? So just to clarify, this whole thing, looks like a loop and the essential components of the loop are motor, neurons, contract muscles.
Sensory neurons of
which there are a bunch of different varieties of. In this case, what we're calling the spindles are sensing stretch within the muscles
and if a given muscle is elongating because of the increased range of motion of a limb, those Sensory neurons send an electrical signal into the spinal cord. Such that there is an activation of the motor
neuron, which by now should make perfect sense as to why that's useful it then. Shortens up the muscle, it actually doesn't really shorten the muscle that
contracts. The muscle, that brings the limb
Back into a safe range of
motion. Okay? So this process is very
fast. It was designed to keep your body together and
safe. It's designed to make sure that you don't, you know, take your arm and swing it behind your torso and it just
goes all the way back to the middle of your back. And unless you're a contortionist, you've trained that kind of level of flexibility. That would be terrible because it could provide a lot of damage to the muscles and to the connective tissue and so forth. So that's one base.
Basic mechanism that we want to hold in mind. This idea of a spindle that senses stretch and can activate contraction of the muscles and shorten the muscles. The next mechanism I want to describe and once again, they're only two that you need to hold in mind for this
episode. This other mechanism has a lot of the same features as the one I just described but it has less to
do with stretch. In fact, it doesn't have to do a
stretch as much as it has to do with sensing loads. So at the end of each muscles, you have tendons.
And there are neurons that are closely associated with those tendons that are called Golgi tendon organs, right? These are neurons that are sensory neurons that sense how much load is on a given muscle, right? So if you're lifting up something very, very heavy, these neurons are going to fire.
Meaning they're going to send electrical activity into the spinal
cord and then those neurons have the ability to shut down, not
activate, but shut
down motor neurons.
And to prevent the
contraction of a given muscle.
So, for instance, if you were to walk over and try and pick up a weight, that is
much too heavy for you,
meaning you could not do it without injuring yourself and you start to try and heave that weight off
the ground. There are a number of
reasons why you might not be able to lift it, but let's say you start to get it a little bit off the ground, or you start to get some Force generated, that would allow it to move,
but the
force that you're generating could potentially
rip your
Muscles or your tendons off of the bone, right? That it could disrupt the joints, and I could tear ligaments.
Well, you have a safety mechanism in place. It's these Golgi tendon organs. These GTOs, as they're
called, they get activated
and shut down the motor neurons and make it impossible for those
muscles to contract.
Okay, so on the one hand we have a mechanism that senses stretch and can figure out when stretch is excessive. And when the system detects that stretches is excessive, it activates the contraction of
muscles.
And then we have a second mechanism that sends
his loads and when tension or
loads is deemed
excessive by these circuits and remember, these circus don't have a
mind, they don't go, this is excessive, they just sense loads and when those loads
exceed a certain threshold, well then those GTOs as Golgi tendon organ, send signals into the spinal cord that. Shut down your motor neurons
ability to contract muscles so that you no longer can lift that heavy load.
So both of these are protective mechanisms but both of these can be
Leverage in a very logical way and in a very safe way, in order to increase your
limb range of motion. So, there are a
couple things I want to point out before going a little bit further, into how your
nervous system controls. Flexibility and stretching. Those key points are the following,
there are now dozens, if not hundreds of studies that show that a dedicated stretching practice
can improve, limb range of motion. Now,
for many of you listening, you're probably saying duh
But I think it's important to point that out, that a dedicated stretching practice can
increase, limb range of motion.
And as you'll soon, learn there are
specific mechanisms that can explain that affect.
The second point is one of longevity and when I say longevity, I don't necessarily mean
late-stage aging.
We all undergo a decrease in limb range of motion unless we do
something to offset that decrease
and the current numbers vary from study to study, but if you look and masculine,
Look at all of those studies and you basically find is that we start to experience a decrease in flexibility from about age 20 until about age 49. That's pretty dramatic. And then of course it will continue
after age
49 but basically it's a 10%,
decrease every 10 years.
So we could say it's a 1% decrease per year. Although it's not necessarily linear. What do I mean by that? Well, it's not necessarily that on your 21st birthday.
You are one percent less flexible than you were on your 20th. Birthday and the
He stood by 1% per year, some of these changes can be nonlinear so you can imagine the person who's doing
just fine in terms of
flexibility between 20 and 30 and then you know they get to 32 and suddenly they've lost five percent of their flexibility.
Now of course there will be a ton of Lifestyle factors. If your regular practitioner of yoga,
if you have a dedicated stretching practice, if you're doing other things to improve your muscle contract abilities, you're doing resistance
training, it turns out can actually, indirectly improve flexibility. There are a number of different factors.
The key point is that maintaining some degree of flexibility and maybe even enhancing range of motion and
flexibility
is of immense benefit
for offsetting injury provided. It's not
pushed too far. There are a number of people who have pushed their limb range of motion so far that they experience all sorts of
injuries. Both acute and chronic injuries today will also talk about how to avoid those scenarios,
Okay? So we've established that there are mechanisms within the spinal cord
muscles and connective tissue. Those
It's the motor neurons, the spindles the GTOs and of
course, the muscles themselves and connective tissue tendons, but also other
forms of connective tissue.
That establish whether or not a limb is going to stay within a
particular range of motion or
not. And whether or not a limb is going to be
allowed by the
nervous system to pursue
or handle a given load. A given tension.
There are also mechanisms that arrived to the
neuromuscular system from
higher up in the nervous system from the brain
and those mechanisms involve a couple of
different facets that are really interesting and I think that we should all know about. In fact today, I'm going to teach you
about a set of neurons
that I'm guessing 99.9% of you have never heard
of including all you
neuroscientist out there. If you're out there and I know you're out there
that seemed uniquely enriched in humans and probably perform
essential roles in.
Ability to regulate our physiology and our emotional state.
So, within the brain, we have the
ability to sense
things in the external world. Something we called X tarot ception, and we have the ability to sense things in our internal world within our
body called interoception. Interoception can be the volume of food in your
gut whether or not you're experiencing any organ pain, or discomfort whether or not you feel good in your gut and in your organs that's
actually kind of feeling. I feel great. I feel sated. I feel relaxed but those are all different forms of interoception.
The main brain area that's associated with interpreting, what's going on in our body is
called the insula, ins Ula. It's a
very interesting brain region. It's got two major parts. The front of it is mainly concerned with things like smell,
and to some extent vision and to some extent, other things that
are arriving from the external world
and combining with what's going on internally and making sense of that of all that or at least routing that information elsewhere in your nervous.
System to make decision. Like if you smell something good to approach it or if you smell something bad to avoid it, the front of the insula is really doing all of that kind of stuff. Along with other brain areas, the posterior insula, the back of the insula that is has a very interesting and distinct set of functions.
The posterior insula is mainly concerned with what's going on
with your somatic experience.
How do you feel internally and how is the movement that you happen to be doing?
Doing.
Combining with your internal state
to allow you to feel. As I like to say the nervous system mainly batches things into yum like oh this
is really good for me. Yuck, this is really bad for me and I need to stop or met.
This is kind of neutral. Okay. So this isn't about food but
we could say for most stimuli most senses whether or not their senses of things internally or externally. Our nervous system is trying to make decisions about what to do with that information and so it mainly batches
information into Yum. I want to keep doing
this or
Watch this thing or continue down some path
of movement or eating or staying in a temperature environment Etc or yuck. I need to
get out of here. I don't want any more of this. I don't want to keep doing this. This is painful or aversive or
stressful and then man. So if it doesn't really matter, I can just kind of stay right here or not. Yum yuck and met. Well
in your posterior insula, you have a very interesting population of very large neurons. These are exceptionally Gnar
Our large neurons
called van Economo neurons. These are
neurons that are again unbeknownst to most neuroscientist and they seem uniquely enriched in humans. Chimpanzees. Have them
and some other large animals have them. So they're found in
Wales chimpanzees elephants and in humans but even though we are much smaller than most whales and
even though we are much smaller than most elephants, I mean remember there are baby elephants. As far as I know, they haven't bred
Up like, like many elephants yet. They seem to have a a teacup version of pretty much every dog breed can look that up. I don't know. I certainly have mixed feelings about this notion of trying to downsize everything to the point where you could kind of like the pocket size, Bulldog, I think of some day will arrive. I'm not a fan of that, kind of downsizing of different breeds,
but because there aren't teacup elephants and teacup
gorillas, and teacup chimpanzees and so forth.
Most all of those other species are larger than us. They have these Vanek.
Animo neurons. And we have these
van Economo neurons,
but we have in upwards
of 80,000 of these things. In our posterior insula, these other species tend to have somewhere in the range of 1,000 to maybe 10,000. Or so,
why is that interesting? Well, these ven Economo neurons have the unique property of integrating. Our knowledge, about our body
movements, our
sense of pain and discomfort and can drive mode.
Additional processes that allow us to lean into
discomfort and indeed to
overcome any discomfort. If we decide that the discomfort that we are
experiencing is good for us or directed toward a specific specific goal.
This knowledge turns out to be very important to keep in mind because as we migrate this conversation toward
the things that we can do to enhance flexibility and stretching
you'll soon, learn that there are moments within a stretching protocol where you have the opportunity to either
override pain and discomfort.
It's a kind of relaxed
through it or push through it, right?
There's a decision fork in the road there and I'll tell you which work in the road to
take or to say, ah, I'm not going to do that. I'm going to allow these natural reflexes of the spindle to kick in and just essentially
stopped me from stretching if given limb isn't designed or shouldn't be stretched that far.
So, I'd like you to keep these van Economo neurons in mind.
I should mention there named Van Economo because the guy Constantine been Economo, they discovered them at the end of the
1800s early
1900s decide to name them after himself as many scientists do or certainly. The neurologists and Physicians are famous for naming things after themselves.
These van Economo neurons, turn out to be very important to keep in mind, as we embark on our exploration of what sorts of
stretching practices can be best applied to increase flexibility,
because
Whether or not you undertake a mild moderate or
intense flexibility training,
you will no doubt encounter a scenario at some point where you will have to ask yourself. Do I quote, unquote, relax into the stretch, or do I? Try and push through just a little bit of
discomfort. And I'll explain how to gauge that decision in a very specific and ideally safe way. And I'll give you some tools that will allow you to make that decision in the way that
This preserves the Integrity of those neural circuits
that I described earlier and can keep you safe
these van Economo neurons sit in the exact position. That one would want to be able to evaluate what's going on in the body, in particular, what's going on in terms of limb movements,
how that relates to our feelings of discomfort. And
then there's the other
aspect of these van Economo neurons, which is that
these van Economo neurons are connected to a number of different brain areas that can shift our
Eternal state from one of so called sympathetic Activation. So this is a pattern of
alertness and even stress, sometimes even panic but typically alertness and
stress, 210 so-called parasympathetic
activation to one of relaxation.
Often times, you'll hear that stretching
should be done by relaxing into the stretch.
Well, what does it actually mean to relax into the stretch? Well, these van Economo neurons, sit at this Junction where they're able to evaluate.
What's going on inside? Our body and allow us to access neural circuitry is by which we can shift our relative level of alertness down a bit, or a relative level of stress down a bit.
And thereby
to increase
so-called parasympathetic activation
and to literally override some of those spindle mechanisms, even the GTO mechanisms but especially the spindle mechanisms
at the neuromuscular and muscular spinal
Ian.
And in that way, gently subtly override the reflex, that would otherwise cause us to contract those muscles
back. The reason that's possible is because
your brain has those other kinds of motor neurons. The upper motor neurons, that can both direct meaning control and can
override lower motor
neurons. I'll give you a brief example of this that you've already done in your
life and that we all have the capacity for
what I'm referring.
To is the monosynaptic stretch reflex. This is something that every first-year Neuroscience graduate student learns, which is that, if you were to step on a sharp object, with a Barefoot, you would not need to make the decision to retract your
foot. You would automatically do that. Provided you have a healthy nervous system.
There are mechanisms in place that caused the retraction of that limb by way of ensuring that the proper muscles contract and other
muscles.
Do not contract in fact that they fully relax. Okay, so in the case of stepping, on a sharp object, like a piece of glass or a nail or attack, you would essentially activate the hip flexor to lift up your foot as quickly as possible in doing.
So that same neural circuit would activate a
contralateral meaning opposite side of the body.
Circuit to ensure that the leg the foot that's not
stepping on the sharp
object would do exactly the
opposite and would extend
To make sure that you don't fall over all of that happens reflexively, it does not require any thought or decision making. In fact,
humans without any neocortex literally there. Who are dussehra buret?
or an animal that doesn't
have a nice Ada sir, but I mean lack of cerebral cortex
They can perform that because it's all
controlled by circuits that are basically below the brain and in the spinal cord.
There's a little bit of activation of circuits in the kind of deeper parts of the brain, but basically, you don't need to
think or decide in order to do that. However,
if your life depended on walking
across some sharp objects, let's say, let's make it a little less dramatic. So it's not like the Die Hard movie or something. We have to run Barefoot across the glass, although that's a pretty good example of what I'm describing.
Being
here. But let's say you had to walk across some very
hot stones to get away from something that you wanted to avoid. You could override that stretch reflex
by way of a decision made with your upper motor, neurons, your insula and your cognition, and almost certainly those van
Economo neurons, which would be
screaming. Don't do this, don't do this, don't do. This, could shuttle that information to brain areas that would allow you to override
the reflux and essentially push through the pain and maybe even in fact even not
Perience. The pain to the same degree or even at all.
So, these van Economo neurons, sit at a very important Junction within the brain,
they pay attention to what's going
on in your body pain, pleasure, Etc.
And that includes what's going on with your limbs and your limb range of
motion. They also are paying attention and can control the amount of activation kind of alertness or calmness that you are able to create within your body, in response to a
Given sensory experience. And as I mentioned before they seem to be uniquely enriched in humans, they seem to be related to the aspects of our Evolution. That allow us to make decisions about what
to do with our body in ways that other animals, just simply can't.
Before we go any further, I want to give you a
practical tool that you can, of course use,
but that will also give you insight and experience into your muscle
spindle spinal cord circuit mechanisms
So what I'd like you to do
is if you're in a proper place to do
this, you're going to stand with legs straight. Meaning he's not bent and you're going to try and touch your toes or for some of you that's going to be very easy and you might even be able to put your hands
flat on the floor. I don't have that kind of flexibility is pretty easy for me to touch my toes.
I don't care if you round your back or not,
although ideally, I would say don't round your back not because it's bad to do so necessarily but just to try and keep this the same from trial.
Trial as it were.
So try and
get a sense of what your range of motion is in terms of bending over at the waist. While maintaining a flat back and try to touch your toes or even touch the floor. Maybe again, you can even go hands. Flat to the floor, maybe even far out in front of you, okay?
Now what I'd like to do is stand back up and I'd like you to
contract your quadriceps as hard as you possibly can for about 5 to 15 seconds. Let's say 10 seconds just to keep
Keep things more or less normalized. This obviously is not super controlled experiment.
So, to contract your quadriceps for those either, don't know, you're going to extend your lower limb out,
so this would be like kicking, although don't do it too quickly. You're going to kick out your your foot. You should feel your quadriceps contract on the top of your thighs and you're going to try
and consciously contract them as hard
as you can, okay? Typically if you want to point your toe, back towards your near Shin, that's also going to help somewhat to contract even
And harder.
Okay, so do that for about 10 seconds.
A lot of you will do this just while standing
contract contract
contract. Okay, then release it, and then now, go ahead and repeat that stretch, where you're trying to touch your toes or touch the floor. So, this is again,
relying more or less on hamstring, flexibility among other things,
okay? What most of you will find is that you have an immediate increase in hamstring
flexibility or your range of motion has increased. If
you didn't experience that, then I would encourage you to try and
Quadriceps harder and longer. So maybe 20 or 30 seconds and then try this so-called experiment again.
Why would Contracting your quadriceps? Allow your hamstring flexibility to suddenly
increase? Well, the way that our muscles are
organized is such that we have muscles that are antagonistic to one another. So
our quadriceps and our hamstrings work in sort of a push-pull fashion. If you will, they can antagonize one another. So when you move your heel towards your glutes, you are using your hamstring. The hamstring
obviously also
As other things related to hip
movement and when you lift your knee or when it you extend your foot and contract your quadriceps, you are
essentially relaxing the hamstrings. Of course most movements involved. Both quadriceps and hamstring in
synchrony and
at synchrony is really an elegant one but here we're more or
less isolating, the
quadriceps from the hamstrings at least to the extent that it can leverage these spindle stretch mechanisms. So what
happens is when you contract your quadriceps ha
Hard you are relaxing or releasing some of the stretch that's occurring. In those intrafusal spindle
sensory fibers going into your spinal cord. And as a
consequence,
You're able, then to stretch your hamstrings further, or we can be more accurate and say that your
range of motion about the hamstring and it's related joints is
greater when you aren't engaging. That spindle
reflex, which would cause the hamstrings to
contract, okay? So if you are somebody who has
tight hamstrings, there could be a variety of reasons for that.
But part of the reason is likely to be neural and you can release that neural spindle reflex by,
Contracting. The opposite
antagonistic muscle, which in this case is the
quadriceps, the same thing is true in can be leveraged for stretching other muscles. So for instance, if you're going to do a
tricep stretch, the typical kind of overhead where you grab your elbow and you know, move it toward the midline of your body, with the other hand, using your opposite
hand. Well you can do that and then I would suggest trying to flex your bicep
contract, your bicep that is
while doing that. And for most people, you'll notice a increase in the tricep
range of
Emotion, or ability to kind
of lean into, or to relax into, or to push that stress
stretch. Scuse me a little bit further. Now for you physios out there, and for those of you that have backgrounds in
kinesiology, I want to acknowledge, of course, there are other
mechanisms that are coming into play there, actually neural connections, within the joints themselves that are providing, proprioceptive feedback, etc, etc.
But this is simply to illustrate that part of our
range of motion is determined
By the spindle mechanisms that I spent some time focusing on earlier.
And indeed, this approach can be leveraged toward creating
increased. Limb range of motion, not just for the hamstrings, but for your quadriceps. So for instance, if you have tight quadriceps, you can do the opposite. You can contract your hamstring very intensely for let's say, 10 seconds or 20 seconds or 30 seconds. So that would take some conscious effort of bringing your heel up towards your glutes.
You could do that in a way, that you're really trying to contract those muscles hard. You'd have to use some deliberate hamstring activation, their meaning, you have to use those upper motor neurons and the other aspects of your your upper brain power as it were
to try and really
contract your hamstrings as intensely as possible. Then you would relax that and then you would do your quadricep stretch again. And if you did a
pre hamstring contraction measurement of
your quadricep flexibility, and then you did a
post hamstring contraction,
Measure of your quadricep flexibility,
almost certainly you would find that that flexibility had increased. Now, of
course, the muscle really didn't change much. The tendons didn't change much. What changed was the patterns of neural activation that were restricting
you from in the first
case stretching your hamstring
or having a to be more accurate, we should say to having a
certain range of motion about the hamstring and it's related joints.
And those brake mechanisms
were removed. And of course then when you contract your
hamstring your removing some of the neural breaks the spindle acting as a brake
and inhibiting that quadricep range of motion. Okay?
So you can imagine this in fact you can apply this for any number of different
muscles, the larger muscles and the sort of biceps triceps and hamstrings quadriceps. That are sort of the simplest place to think about this and to apply it. But in theory and indeed in practice, it really works for
The various muscle groups It's just sometimes harder to access these so-called antagonistic muscle groups.
Now we should take a moment and just discuss.
What actually happens is we get more flexible in the short term and long term.
I just mentioned what happens in the short term. Clearly those don't involve lengthening of the muscles, it's
not like the muscle slide along the bones or that the tendons, really stretch out that much more than they had prior to that kind of you don't exercise but
It is the case that if people stretch consistently over a given period of several weeks or more, that there are changes in the muscles, this gets a little bit tricky in terms of nomenclature and I just want to highlight that because I think that a number of people get frustrated
and Confused. In fact, when we talk about muscles getting
longer, you know, the whole concept of a muscle getting longer isn't really in keeping with reality. But there are elements within the muscles that can change.
Their confirmation. So to get a little bit detailed here, and we won't spend too much time on this, but I just want to acknowledge this
for those of you that are interested in neuromuscular physiology and how it relates to flexibility, you know,
you have your muscle fibers and then you have your so called
myofibrils. So you can imagine kind of a
single fiber that fiber, of course. We'll get input from those motor neurons and then within those fibers, you have what are called sarcomeres. And you can kind of, think about sarcomeres as little segments, kind of like the segments of bamboo if you ever look at bamboo
It's not just one
big stalk. It's got those
little outpouching 's along the
way that going to break up the,
what would be just one big stock of bamboo into different segments but they're all connected. The sarcomeres are somewhat like that. And within the sarcomere is, you have a couple of different components. One thing is called myosin, which is like a thick layer and then the other is actin and those are interdigitated. As we say, they're kind of connected to one, another kind of like have you ever put your fingers
Other from your two hands. If you're going to get,
put your fingers in between one another.
That's interdigitate. Literally interdigitated in this case, so pun intended. And
that myosin and actin kind of move relative to one another and they have a lot
to do with your ability to contract muscles.
When we stretch muscles, when we go through a stretching practice, there are a number of things that
change some neural, some related directly to
connective tissue. But also, it appears from really nice work Ben
Lee done from McGill University. I'll provide a link to a couple of these studies. If you want to dig in there deep more deeply that change the confirmation, the relative size and spacing of some of these things like sarcomeres in the way
that myosin and actin can work together.
But we don't want to think of
muscles as lengthening.
We can however, think about
the resting state of a muscle being slightly different or indeed, very different
then the resting state
of a muscle.
Of somebody or of a limb that has not undergone. Regular flexibility training.
So that's as much time as I want to spend on that because we could spend an
entire hour getting right down into the
details. But I do
want to emphasize however that muscles have different parts. They have fibers. They have
sarcomeres they have - in they have act in. But the idea of making our muscles longer that reflects a number of processes that occur
basically within an existing muscle, length
are the length of our muscle bellies and where our insertions are
Our
relative to our connective tissue in our limbs
is genetically determined,
right? Some people have, for instance, a bicep that goes all the way from the crook of their
elbow up to their shoulder, right? And some people can,
you know, if they were to put their arm at a 90 degree
angle, could put two or three fingers between their bicep and their elbow, they
have a, we can say a shorter bicep relatively shorter.
Now, the reason I mention these highly detailed seller mechanisms is because, as we
Art to embark on different protocols
for using stretching to increase flexibility and range of motion. We need to ask
ourselves. What is
preventing our ability to extend range of motion?
Is it the spindle,
right? Is it because the muscle is stretching too much. Oftentimes, it can be because of
that. And or because of a sense of pain or simply a sense that the muscle is not in a position that it's been in before that's
unrelated to pain or two spindle activation
and off.
Oftentimes, it can be related directly to these changes in the conformation of
myosin and actin and within the context of the sarcomeres. Now of course you can't
peer into or sense your individual sarcomeres however you do have neurons that
innervate these areas
and that send that sensory
information back into the spinal cord and up to your brain to
interpret. So you'll find that as we move along, there are specific adjustments that you can make at the both the macro level meaning. How much
Movement to insert into your stretching, right? As it can be a static or dynamic or even a ballistic stretch or, for instance, at the micro level that even just a slight sub millimeter or mm, increase in the stretching of a given
muscle. And it related
issues can translate into an increase range of motion performance as a quick. But relevant aside, I thought I'd share with you something useful. That's also grounded in this
notion of antagonistic muscles.
Of those of you that do resistance training, whether or not it's with body
weight or with physical weights or machines, what
have you, you may have found that.
If you, let's say we're to do three
sets of a pushing exercise, so this could be push-ups, this could be bench presses, this could be shoulder presses, something of that sort. And then
later in the workout you were to do, let's say
machine, pull Downs, or pull-ups, or chin-ups of some sort. So, a pulling exercise,
typically, what you would find is if you were to do,
what's
And called straight sets. So you would do
three sets of push-ups. Let's say with two minutes of rest in between
that you might be able to get a certain number of repetitions on the first set. Just for sake of example, let's say you can get 10 repetitions on the first set and then you get
eight repetitions on the second set. And then you get
six repetitions on the third set with two minutes in between and
then you would move on at some point to you're pulling exercises. And similarly, let's say you were doing chin-ups or pull downs and you would get
Ten repetitions rest, two minutes, eight repetitions rest, two minutes and six repetitions. Okay, fine. Well, typically what people discover is that if they interleave, they're
pushing and pulling exercises, provided they do that
for muscles that are antagonistic to one another. So in this case, pushing with the chest, shoulders, and
triceps for the pushing exercises and pulling with the back and biceps. And, of course, there are other muscles involved as
well, but because those muscle groups are at least in part antagonistic to one another
Other what people often find is that, if they were to say, do they're pushing set, get 10 repetitions then move to a pulling set after just say 60 seconds and perform that pulling
set,
then go back to the pushing set. Then go back to a pulling set Push, Pull Push, Pull in other words interleaving their sets, even if they were to maintain the same amount of
rest between sets of pushing and sets of pulling
What they discover often is
that the
drop in the number of repetitions that they get is somewhat offset. So rather than get 10 8, 6
as it were with the straight sets, it will be
ten nine
eight. So
what this means is not that you're increasing the total rest time, 24
minutes between sets because then of course it wouldn't be
equivalent. But rather that while maintaining the same amount of rest between sets for this same muscle,
By going from Push, Pull Push Pull of antagonistic muscles, you're able to have improved performance and the reason for that has everything to do with what we were describing before, which is that typically if you were to do, push set rest, push set, rest push set, rest well in between those sets. And in fact, actually during those sets of pushing the pulling
muscles that would be involved in the chin UPS or pull down,
Etc are
actually relaxing or at least are being released of some tension
including the activation of the spindles among other things.
So that's a long-winded. Way of saying that interleaving push and
pull of anti antagonist. Accepts
can leverage some of the same neural circuits that were talking about
leveraging for sake of increasing flexibility. Now I
offer this to you as a
tool that you can try
one of the challenges with using this tool. However is that
you often have to occupy multiple sites
within the
You know, if you're doing this at home and you have your own gym, that's one thing if you're doing this in a gym where you have multiple pieces of equipment with then you become that person
who has essentially taken over some small corner, or multiple corners or machines within the gym.
And often times, you'll find that you'll walk
back to a machine or you'll walk back to a given resistance exercise, in someone has now taken it over. And the whole thing could be thrown off.
So it takes a little bit of orchestrating in order to do properly, but in general, what people find is that this can allow
you to enhance performance overall
All of these individual movements again while maintaining the same amount of rest. And even if you choose not to do this
I encourage you to pay attention to this as a concept because again it's leveraging this idea of
antagonistic muscles flexors and extensors. Antagonistic neural relationships between the spinal cord mechanisms that control one set of muscles
and activating those muscles. Allowing the opposite
antagonistic muscle to relax and
To perform better on its next set.
So now, I'd like to shift to the question of what types of stretching can and should we do to increase limb range of motion? If our goal is to do that in the most efficient way possible, because I realize that most people don't
have endless amounts of time to dedicate to a stretching practice.
And even for those of us that do, I'm sure that you want to get the most outcome for a given effort.
And what are the modes of stretching that are going to allow us to increase our
flexibility and limb range of motion. Most safely now,
there are a number of different types
of stretching or methods of stretching. Broadly defined, we can describe these as
Dynamic ballistic static
and what's called PNF stretching
PN. F stands for proprioceptive.
Muscular facilitation and it involves and leverages many of the mechanisms that I described to you earlier. The first two that I mentioned Dynamic and ballistic stretching, both involve some degree
of momentum and can be distinguished from static and pmf type stretching
now to distinguish Dynamic stretching from ballistic stretching like to focus on this element of momentum. Both involve moving a limb through a given range of motion in
Namek stretching. However, it tends to be more
controlled less use of momentum, especially towards the end range of motion.
Whereas in ballistic, stretching, there tends to be a bit more
swinging of the limb or use of momentum. So I invite you to visualize what dynamic and ballistic stretching might look like in your mind you can even try it. If it's safe for you to try it you can imagine
you're swinging. Your arm up overhead as much as possible, bring it down. I'm doing this because
I'm seated as kind of ridiculous movement to do while seated or perhaps at all.
For instance, you can see Dynamic and ballistic stretching. Anytime someone for instance is holding onto something
with one arm or maybe not
holding on and Swinging
out there their
foot. So, essentially, getting movement about the hip joint, and you'll notice that some people raise it up and pause it and bring it down. That's one form of dynamic stretching, whereas, others will swing it up and cuts or let it carry itself a bit
further due to the momentum at the top of the movement and then just let it drop.
Back down or maybe even control The Descent.
There is an enormous range of parameter space here or
variables that one could imagine and there's
just simply no way that we could subdivide all those, but again, Dynamic and ballistic stretching, both
involve movement. So we have to generate some force in order to create that movement
ballistic stretching involving a bit more momentum or sometimes a
lot more momentum especially at the end range of motion. Now,
both of those are highly distinct from static stretching, which involves holding
The end range of motion. So, minimizing the amount of momentum that's used. So, to
stay with a simple example that we are all now familiar with from our earlier discussion slowly bending over at the waist and trying to touch your toes
or putting your hands to the floor and then holding that and position
before coming up in a slow and
controlled way, such that you reduce the amount of momentum to near zero would be one example of static stretching.
Static stretching can be further, subdivided into active or passive. Right.
There are different
names for these kinds of approaches.
You can hear about the Anderson approach or the John Deere approach. You can look these sorts of things up online. And again, people tend to name things after themselves as some of these
are proprietary related to specific programs. I'm not focusing on those
others. Come to be named after the physiologist or the practitioners that initially popularize them. As is always the case. There's always a naming
and renaming and claiming of territory with these things.
for the time being, I'd like to just emphasize that static
stretching, can be both
active where there's a
Dedicated effort on the part of the stretcher. You to put force behind, the hold to kind of extend, or literally to extend the range of motion. And then there's also passive static stretching in which it's more of a relaxation into a
further range of motion and that can be a subtle distinction. And there are other ways in which we can further distinguish, active and passive static stretching but nonetheless static stretching involves
Both those types of elements active and
passive. But is
really about eliminating momentum
and then there's the pmf, the proprioceptive neuromuscular facilitation and proprioception has several different
meanings in the context of Neuroscience and Physiology to just keep it
really simple for today. Proprioception involves both a knowledge and understanding of where our limbs are
in space and relative to our body, typically relative to the midline. So the
brain is often trying to figure out
Where are
our limbs relative to our mid line down the center of our body? And we know where our limbs are based on, so-called proprioceptive feedback, so that's feedback that comes
from Sensory neurons
right now, you know what Sensory neurons that are
essentially monitoring or responding to events within the joints, the connective tissue, and the muscles. And within the Deep
components of the muscles, like the spindle reflex and within the tendons like the GTO
The Golgi tendon organ.
So
PNF type stretching
leverages the sorts of mechanisms these these neural
circuits by way of, for instance, you would lie on your back and if your goal is to increase your hamstring, flexibility and the flexibility and range of motion
of other related muscle systems. You might put a strap around your ankle
and pull
that muscle where I should say. Excuse me, that limb towards you and I'm going to pull the muscle towards you're going to pull that limb, your ankle towards you try and get it sort of back.
Your
head and then progressively relaxing into that or maybe even putting some additional Force to push the end range of motion and then relaxing it and then actually trying to stretch that same limb or increase the limb range of motion without the strap, right? Sometimes these are assisted by other people.
So people will even use loads. Sometimes they'll even use a machines, there are a number of different apparatus. I that have been designed for this. Sometimes, it'll involve a training
partner,
There's a huge range of pmf protocols
and those protocols can be done both by oneself with or without
straps with machines with actual weights
or with training Partners. If you're interested in the variation of exercises, to say, Target your hamstrings versus your quadriceps, versus your shoulders versus your chest, muscles Etc, your neck muscles. And
so on there is an enormous range of information on Dynamic ballistic, static, and pmf
stretches, for all the various
Muscle groups and I should say there's some excellent books on those topics. There are also some excellent videos on
YouTube and elsewhere, nowadays, it's pretty easy to find exercises. That
allow you to Target specific muscle groups, again. I encourage you to be safe and how you approach this, and I would encourage you
also to pay attention to the information that soon follows, as to what sorts of protocols,
one would use to apply those exercises, but the number of exercises and the availability of those
Sizes for targeting different muscle groups, with these four different kinds of
stretching is both immense. And
fortunately, thankfully immediately accessible to all of us often at zero cost.
So specific exercises to Target specific muscle groups. Aside, we've now established that there are four major categories of stretching or at least those are the
four major categories. I'm defining today,
and we can further divide those categories into which are the ones that are going to be most effective
for
Range of motion in the long term, not just in one individual session,
and there have been a number of studies exploring. This I can list out at least four and we'll put those four
as a kind of a cluster under one heading in the show. No captions
that arrive at essentially, the same answer which is that for increasing, limb range of motion. It does appear that static type including pmf, but static type stretching is going to be more
effective.
Give than Dynamic and ballistic
stretching. So at least to my mind, this is good news. Why is it good news to me? Well, while Dynamic and ballistic stretching can be immensely useful, for improving performance of specific movements
in particular in the context of particular
sports like tennis or in sprinting or frankly for any sport. They do carry with them. A certain amount of risk because of the use of momentum. So
you don't need
Highly trained in order to perform them. In fact, there is a place and we will describe when one would want to apply dynamic or ballistic stretching. I'll just give away for now. I
think that most physios out there and certainly, the ones that I spoke
to Doctor Andy Galpin, dr. Kelly Starrett, and a few
others.
Point to the fact that doing some safe Dynamic and ballistic stretching, prior to say a resistance training session, or maybe even prior to a cardiovascular,
training session can be useful
both in terms of range of motion effects. And in terms of neural activation effects,
I don't want to use the words warm up, because warming up is typically associated with increasing core body, temperature as it should be. But
for engaging, the neural,
And becoming familiarize with the neural circuits that you're about to use in other
movements while also, increasing the range of motion of the joints involved in those movements so
that you can perform them more safely and more confidently. So I'm certainly not saying I want to repeat. I'm certainly not saying that Dynamic and ballistic stretching or not useful. They absolutely are.
But in terms of increasing limb range of motion in the
long term
of truly becoming more flexible as opposed to transiently more flexible.
Attic stretching, which includes
pmf?
Appears to be the best route to
go. So if your goal is to increase, your limb range of motion for a given muscle group,
perhaps for all muscle groups, although can imagine that would be pretty tough. I mean, you're not going to spend time. I could imagine working on your tongue muscle control or neck muscle control and every muscle
control. But most of us want to
reduce so-called tightness in air quotes and increased limb range
of motion for certain muscle groups and it appears that. The best way to do that is going to
be
Stretching of some kind which raises the question of how often to do that static stretching and
how long to
hold those static stretches
and we can also
ask the question. We should ask the question where to hold those static stretches. Is it
always a good idea to hold those static stretches at the end or the point of maximal range of motion? We're going to address that. Now there's some terrific science around this a slightly older study but nonetheless powerful one, because it provided a foundation for
A lot of subsequent work which basically serve to just
confirm the answer, they got here is a study from Bandy at all in the title of the study is the effect of time and frequency of static stretching on the flexibility of the hamstring muscles, the study involving 93 subjects so 61 men 32 women. Ranging in
age from 21. To 39
years be broad demographic who had limited hamstring muscle flexibility. Here, I'm paraphrasing and randomly assigned to one of five groups.
So the for stretching group stretch five days per week for six weeks, the fifth Group which
served as a control, did not stretch
the results. Clearly show that quote, the change in flexibility appear to be dependent on the duration and frequency of stretching. This is great. This tells us that stretching for a given amount of time, scales with the amount of RIT limb range of motion Improvement that one will see there were many interesting findings within this study but the one that I'd like to highlight most is quote
The results of this study suggest that 8:30. Second duration, is an effective amount of time to sustain a hamstring muscle, stretch in order to increase range of motion. No, increase in flexibility occurred. When the duration of stretching was increased from
30 seconds to 60 seconds
or when the frequency of stretching was
increased from 1 to 3 times per day,
okay? So we're now we're starting to lay down some parameters. What? This study reveals and what subsequent
studies? Tell us and we will get into those.
Sequence studies. Is that ideally one would do static stretches that are held
for 30 seconds,
perhaps more in certain instances and I'll explain when that can be useful. But here holding those stretches for more than 30
seconds did not turn out to be. Additionally useful.
So if you're going to stretch your quadricep, for instance, and you're going to
hold that stretch in static faction, remember not using momentum and you can use the mental tricks of
Either trying to push through the pain which I don't recommend necessarily. I think that makes us prone to injury or to relax into the stretch, but nonetheless,
providing some Force
typically with the with a hand in order to your pull your ankle back. If you're doing a quadricep stretch, some people might do this on the edge of a sofa. Remember there are a lot of different exercises and ways to do this that you can explore
elsewhere. Well, holding that static stretch for
30 seconds. Appears to be
sufficient
to stimulate an increase in limb range of
In overtime. Again, these are protocols that were used repeatedly over time and we'll talk about how often to repeat them in order to get maximum effect. But 30 second holds for static stretches is the number that I think we want to focus on and that most of us are going to want to utilize.
So now let's explore how many
sets of static stretching one ought to do in order to get a
maximum range of motion
Improvement. While not placing us into a system that's going to create injury,
nor a
situation where we have to be
Be constantly stretching throughout the day because again, most of us don't have time to do that.
This issue of sets is an important one. In the context of cardiovascular
exercise, we've talked about the data that support the fact that doing at
least 150,
and ideally, as much as 200 minutes per week of Zone to
cardiovascular, exercise is
very useful for cardiovascular health and for other aspects of health. And of course, there are other aspects of cardiovascular exercise that could be layered onto an into that that can be useful like 90 second maximum Sprint's at
Our
discuss this a lot in the episode with dr. Andy Galpin, and on our episode about
endurance and
we also talked about sets in the context of strength and hypertrophy building building muscle size and or strength in the episode about that. And in particular, in the episode with dr.
Andy Galpin and there we could also arrive at some specific parameters
and it's going to vary. Of course, between individuals depending on how hard you train whether or not you take sets to failure, your repetition range,
Etc, but in the context of strength and hypertrophy
Building. We arrived at a approximately six, maybe as many as 10 sets per week per muscle group. Some of that work
is done as direct work to a given muscle group. Some of that work is indirect. So doing certain pulling exercise, of course, will Target the latissimus dorsi muscles but also the bicep. So if you that doesn't necessarily mean, you have to do 10 sets for the biceps and for the lats sometimes, you're getting some indirect work etc. All of that was delineated in the episode with dr. Andy
Galpin, and we arrived at those
Numbers of sets
according to the same criteria that we will apply here, what is the minimum number of sets both to maintain and to improve a given mode
of performance strength and hypertrophy or cardiovascular health again to either maintain or improve and we can do the same
thing for improving or maintaining range of motion. Because as I mentioned earlier, the data point to the fact that if we don't do
some dedicated work to improve range of,
And over time, we will lose our flexibility and limb range of motion over time, just by virtue of the fact that we're not doing anything to offset that.
So whether or not you want to maintain re-establish or gain, limb range of motion, static stretching of holds of 30 seconds appear to be best. Now, the question is, how long
should you do that? And how many sets should you do that? How many times a week? Should you do that?
And to answer those questions going to turn
You what I think is a really spectacular review. This was a review that was published in the year 2018, so it's fairly recent first author,
Thomas, it wouldn't Thomas. Last author Palma, we will put a link to this in the show. No caption.
The title of the paper, is the relation between stretching typology, and stretching duration, the effects on range of
motion. It's a very straightforward title.
This is a review article that explored a number of different studies.
Had criteria for whether or not. Those studies could be
evaluated in the context of the questions. Here had some quality standards, and some other standards that they applied.
And basically window down large collection of studies to a remaining 23 articles that were able to be considered, quote, eligible and included in the quantitative synthesis done here. So, key points from that
quantification and synthesis done in this paper,
first of all, and I quote, all stretching typology use.
Showed range of motion improvements over a long-term period. However the static protocols
showed significant gains with a p-value less than 0.05, which means a probability that cannot be explained by chance alone
when compared to ballistic or pmf, protocols. So again, what we're hearing is that static, stretching
is the preferred mode for increasing limb range
of motion. Although here they make the additional point that static stretching might even be superior, not
just to ballistic
stretching but
But also to pmf
protocols, because before, as you may recall, there was a distinction between ballistic and dynamic and static and pmf. And so,
here it appears again, that static stretching is come sort of rising to the top of the
list as the optimal approach relative to all other stretching approaches, at least in the context of increasing limb range of
motion.
The authors, go on to say time, spent stretching per week seems fundamental to elicit range of movement, improvements when stretches are applied for at least or more than five
minutes per week. Okay, this is critical. This is not
5 minutes per stretch. Remember 30 seconds per static stretch but at least 5 minutes per week, whereas the time spent stretching within a single session, does not seem to have a
significant effects for range of motion gains. If this is getting confusing, I'll make sure that you soon. Understand exactly.
Really what we can export from these
conclusions.
The data indicate that performing stretching at least five days a week.
Now, some of you may already be groaning for at least 5 minutes per week, okay. So five days per week, that's a lot. But at
least five minutes per week. Five minutes per week
is not that much using
static stretching, may be beneficial to promote range of motion and provements. Okay, I've read this study in detail. Now, they highlight again, the reduction in flexibility that occurs from 20, 49 years of age, and so on how a cute bow
Of short-term stretching up to three weeks can improve stretch tolerance. I think that's a key point that in the short term, the first three weeks of embarking on a stretching and flexibility program, much of the improvements come from the short-term neural
improvements that we talked about before of inhibiting, the spindle
reflex and so on, and also a stretch
tolerance, a comfort with doing the movement and maybe even a comfort in overriding, some of the pain mechanisms, I'll talk a little bit more about that in just a bit. And the particular utility of yoga something that I don't often.
This, but that after reading this article that I'll mention in a little bit, I'm considering perhaps taking up some form of yoga protocol.
Now I've already highlighted some of the key takeaways from this study namely that we need to get at least 5 minutes per week of static stretching per muscle group. And based on the previous paper that we talked about, we need to divide that five minutes into
sets of 30 seconds each.
And as I mentioned earlier, it doesn't seem
The case that you can
do all of that in one day. Unfortunately,
it does seem important that the frequency
of stretching practice distributed throughout the week is important. So let's talk. Protocols, we are
now talking about doing a static stretching, so holding so limiting momentum, and
holding a stretch for 30 seconds per set, we're
talking about trying to achieve five minutes per week of those static holds but that we can't do it all in one session because the
frequency
Of sections, distributed throughout the week, correlates with the improvements in limb range of motion. So what this means
is that we should probably be doing anywhere from two to
four sets of
30, second static, hold
stretches.
Five days per week or some variant thereof
and I do say some variant thereof because it turns out that even though there was that earlier study that we talked about that holding a stretch for more than 30
seconds and that case 60
seconds didn't turn out to be, additionally, beneficial, it appears that if you do, hold those stretches for 60 seconds
per static stretching. Set.
For instance, you can get away with stretching fewer days per week overall. So
In order to make this as clear as possible
because I do realize there are a lot of parameters and you might be asking, why
didn't you just make me a list of the exact things I should do? Well, it doesn't work that way because once you understand the mechanisms, and once you understand your particular goals, this information is designed for you to be able
to construct a stretching program, that is tailored to your specific goals. If I just gave you the stretching program that I'm doing, or I should say that I'm soon to be doing because I'm soon to be doing one based on the research, for this particular
episode. Well, that wouldn't
Be beneficial for you because for instance, if you have very flexible hamstrings,
but not very flexible quadriceps or you are somebody who is
engaged in sport or not engaged in sport.
What you need to do is going to vary somewhat. So what would have effective stretching protocol? Look like,
we're all trying to improve limb range of motion for different Limbs and different muscle groups. But just, by way, of example in, that's because the one we've been using, let's talk about
hamstrings for the time. Being, this
could, of course, be applied to other muscle groups.
Let's say you want to improve
hamstring, flexibility and limb range of motion about and around the hamstring and involving the
hamstring.
You would want to do three sets
of static stretching for the hamstring again, easy to find such exercises on the internet.
You would do that by
holding the stretch for 30 seconds, resting some period of time, then doing it again holding for 30 seconds, resting some period of time and then holding it for 30 seconds that would be one training session for the hamstrings. I have to imagine that you'd
probably want to stretch other muscle groups as well in that same session although at least as far as I could tell there were snow data, pointing the fact that you couldn't do your hamstring stretching, one part of the day and your quadriceps stretching another part of the day. But presumably you're going.
Want to combine your flexibility training in into one single session.
So, three sets of 30 seconds, each get 90 seconds and you would do that ideally five times a week, or
maybe even more, because it does seem like frequency distributed throughout the week is an important parameter. Now, one thing that we have not highlighted, or at least described
is how long to
rest between stretching sets. And
despite my efforts, I could not find research
Search back information that pointed
to whether or not 30 seconds of rest for every 30 seconds stretching or
60 seconds, rest for every 30 seconds
stretching was ideal. I think it's reasonable to assume that doubling the amount of time for the interleaving rest would be appropriate or at least doable. If anyone out there has knowledge about rest between stretching sets, and has some physiology or some biology or some experiential information as to why
Given ratio of duration of static stretch to rest in between static stretch, sets ought
to be used, please put it in
the comments on YouTube that would be a terrific way for us to get that information. I'd love to do any follow-up to links that you provide and so on.
But now we're starting to build into a protocol that is backed by the scientific data.
Three sets of 30 seconds of Holt done, five times, or maybe even six times per week,
one thing that did show up in,
In
my exploration of the peer-reviewed research.
Is this notion of warming up
for all this? We haven't talked about that
yet, in general to avoid injury. It's a good idea to raise your core body temperature a bit before
doing these kinds of stretches even these static stretches, which we can sort of ease into and don't involve ballistic Movement by
definition. And the basic takeaway that I was able to
find was
that if we are already warm from running, or from weight training, or from some other,
Activity that doing the static stretching practice at the end of that weight, training or cardiovascular, other physical session would allow
us to go immediately into the stretching session because we're already warm so to
speak. Otherwise raising ones core body
temperature by a bit by doing five to seven, maybe even 10 minutes of easy, cardiovascular exercise or calisthenic movements. Provided, you can do those without getting
injured. Seems to be an ideal way to warm
up the body.
Stretching. We should
be warm or warm up to stretch. All those
warm ups don't have to be extremely extensive and then just by way of logic doing the static
stretching after resistance
training or cardiovascular, training seems to be most beneficial in fact, and unfortunately, we don't have time to go into this in too much detail today.
I was able to find a number of papers that make the argument that static stretching prior to
cardiovascular training and maybe even prior
to resistance training can limit our
In running and resistance training. I
realize that's a controversial
area. You have those who say? No, it's immensely beneficial. You have those who say, no, it inhibits performance in the those that say, no. It's a matter of how exactly perform that static stretching and which muscle groups, and how you're doing this and how much time in between
static stretching and performance, but to leave all that aside doing static stretching after some other form of exercise. And if not
after some form of exercise after a
Brief warm-up to raise your core body. Temperature definitely seems like the right way to go. Now, for some of you out there and I confess for me, as well,
doing something five days a week, seems like a big commitment, even if that commitment is one to only do
three sets of 30 second static
stretches. I say this because you've got the warmup.
I generally like to bring a kind of a
focus and dedication to a practice and of course because when doing these kinds of
protocols,
It's likely that you're not just stretching your hamstring. So it's not just 90 seconds of work with a minute of rest in between but very likely that also doing quadriceps stretching and also doing stretching for the shoulders and stretching
for the back and the neck and so on. And so that entire session is going to take some time and five days a week is a pretty serious commitment for most,
especially for those of us that don't exercise or do athletics for a living, which I don't.
So there is some evidence from the literature that one can get away with or I don't even know that we should think about.
Getting away with. But that one can
do longer hold
static stretches of up to say 60 seconds, but
do fewer total sessions per week. So rather than 3/32
static holds doing 360 s, static, holds, and doing those every other day.
And there really hasn't been a systematic exploration of this. The article that I was referring to just a few moments
ago, this analysis of the
three articles
was combined into this enormous set of tables
and some really quite nice graphs that you're welcome to look at since we're going to provide a link to the study. There are a couple of key
takeaways that I want to mention that are separate from this issue of how long to stretch and how often first of
all,
they describe in their discussion, that there were improvements in range of motion, independent of whether or not people did static stretching, active, stretching, passive, stretching, ballistic
stretching,
Or PNF stretching.
So all of those forms of stretching
will improve limb range of motion. This is essential to point out and I want to emphasize this
static stretching, however, gave the greatest
degree of gains in limb range of motion. And on average, they saw a twenty point nine percent
increase, but some of the other increases, they observed were also quite substantial. So ballistic stretching can also
provide some pretty impressive, limb range of motion improvements.
It's however they tended to be in the range of here. They point out eleven point six, five percent increase or in the case of pmf of fifteen percent
increase. So it appears that the greatest improvements in limb range of motion for your time, spent and effort spent is going to be this minimum of five minutes per week. To elicit, a significant response with five days. Being the minimum weekly recommended frequency to achieve
significant significant range of motion improvements. I
confess. This was pretty surprising to me.
When I compare flexibility training to say resistance training for strength and
hypertrophy. I've had the
experience and I know that other people will have the
experience and I think dr. Andy Galpin would probably agree that
provided one trains hard enough and appropriately that
you don't need to train resistance training five days a week in order to get significant improvements in strength and hypertrophy some people might need to but you
can get a lot of positive
results in
Those variables with less frequent training, certainly with three or four days a week of training
and for cardiovascular training, I'm not aware of anyone having tested whether
or not one very long run each week can actually increase cardiovascular fitness and you're not doing anything else. Although I have to imagine you probably see some improvement compared to not doing anything.
But most people are doing
repeated training, sessions of cardiovascular strength training, not a lot of people are doing five days a week of strength training and
at least that I'm aware of
People are, but most people I think are not and some people are doing five or
more days a week of cardiovascular training. I'm guessing that most people are not doing five days a week of dedicated. Static stretch range of motion directed training, but it does appear that, that frequency about the week, getting those repeated sessions even if they are short for an individual muscle group,
turns out to be important. And so that points to the perhaps the reason why so few people are doing dedicated
Range of motion work. But it also reminds me that all of the studies that were described at least in this review and some of the other ones that were not really show impressive
changes in limb range of motion. I mean, 20 plus percent or even
15 percent with pmf. I mean, these are big changes that are going to benefit us. They're going to offset the age-related
losses. In flexibility for sure. If one is dedicated about these practices
and in many cases, they're going to increase limb range of motion.
Ways that are going to allow us better performance in certain physical Endeavors, certainly better balance, or we haven't really talked
about balance and stability, but
range of motion can impair balance and stability, in some extreme circumstances. But by and large, limb range of motion, lack of tightness,
improved posture, and Pluto, improved physical performance.
Scuse me and things of that sort is something that I think we can all benefit from. And that are key features of longevity. We don't often think of them because we so prioritize cardiovascular health
and the
Between the heart and brain health and resistance, training, and musculoskeletal, hypertrophy, or strength, Etc. But
as I delved into this literature, it really highlighted for me, the extent to which having really good limb range of
motion. At least maintaining limb range of motion as we age from year to year and maybe even improving. Limb range of motion.
Can be immensely beneficial for reducing pain for
again. Improving posture, improving our ability to perform to walk.
Cetera. And indeed, there's a whole literature that relates our limb range of motion to things like pain management of things
related to headache and so on, and so
forth. So, limb range of motion is not
just about becoming a contortionist or being able to complete the yoga class. It really is about maintaining the integrity and the health of the
neuromuscular system, the connective tissue, and the neuromuscular connective Network, because those are indeed working
as an ecosystem and a
network, I'd like to just briefly touch on pmf.
Stretching for a moment.
Again, this is a vast
landscape with many parameters and different practitioners. A lot of competing, opinions out there
to put it lightly. Nonetheless I I do want to emphasize that the pmf training leverages those spindle mechanisms and GTO mechanisms that we talked
about earlier. But
I realized that in describing the quadricep
contraction hamstring stretch little mini experiment that hopefully you did
that I didn't really highlight the
role of the GTOs the Golgi.
In organs that much. And I just would like, to just briefly do that for a moment. The GTOs
have multiple functions. In fact, I think even though
GTOs are in every medical textbook, every physiology, textbook, every first-year neuroscientist learns about them. When learning about the neuromuscular Junctions and the mechanisms of interoception Etc, they are likely to have other functions as well.
And one of the reasons why PNF stretching does work
whether or not you're doing that by using a
rap to, you know, pull back a limb or whether or not you're actively Contracting, your quadriceps to then, release and emphasize stretch range of motion for your hamstrings and related muscle groups, is that
activation of those GTOs, meaning putting loads and tension into that system can inhibit the
spindles in the opposite antagonistic, muscle groups.
So one of the reasons
why flexing or I
A Contracting, your quadriceps really intensely for some period of time, allows your hamstrings to subsequently experience greater range of motion and again, it's not just the hamstrings but the related connective tissue and neural circuits. Etc is
because yes it's quote-unquote relaxing, the hamstrings and the spindle but there's also a direct
relationship between activation of the GTOs in the quadricep.
And release of the spindles in the hamstring and related muscles, this has a name, it's called autogenic inhibition, it's a fancy name for
contraction of one muscle group, providing a relaxation of the other muscle group
that's antagonistic
to it and it relates back to this
idea of interleaving sets in the gym. So if you think back to that example, now it should make sense as to why. For instance, if you do let's say a set of bench presses or shoulder presses.
Then you'd let's say you get 10 repetitions and you fail on the 11th that muscle is very, very fatigued. If you were to rest some period of time and then go back and do another set.
Well during the rest that muscle group has been
relaxing, it's obviously not Contracting the same way, it was during the resistance
set but by going and doing a pulling
exercise that involves the antagonistic muscle group. So strongly Contracting the back muscles, through a pole like a pulldown or a chin-up or a row type exercise.
Your
You're activating or near activating the GTO
system in those pulling
muscles in a way that provides autogenic inhibition for the pushing
muscles. Now again, the physios out there are probably either screaming or banging their heads against whatever sound system. This happens to be arriving through to them saying.
Wait, but in many
cases, the GTO is aren't activated enough to provide that autogenic inhibition, that's
true. But even the sub-threshold activation of those
Intraspinal circuit. So the place where the GTO circuit and the spindle circuit
interact can provide an additional replenishment of say the pushing
muscles while you're activating those pulling muscles and this is at least one not the only but at least one mechanisms by which
interleaving push and pull push and pull for both strength and hypertrophy training. But also for range of motion
stretching type training
can allow you to achieve better results in a shorter period of time.
Time. And I raise this because I want to keep in mind the efficiency of any training program. We just a moment ago established that doing for example, three sets of 30, second static holds can be very useful for the hamstrings. With
let's just say for sake of Simplicity and practicality a minutes, rest in between, but during that minutes rest, you can stretch the opposite antagonistic, muscle group such as the quadriceps, or if you want to use pmf training, you could do.
Any of the quadriceps in between.
So there are a number of different ways in which you can start to enter leave.
Static stretching with PNF stretching. You can start to interleave even pmf type protocols with resistance training although get that gets a bit more complicated. You can really start to construct and build protocols that are ideal for you. What we will do is For an upcoming neural network newsletter. So for those of you that aren't familiar, the huberman lap
podcast has a so-called neural network newsletter. These are monthly newsletters
where we put distilled points from the podcast and oftentimes protocols in a downloadable PDF.
A form, you can access it by giving us your email. We don't share your email with
anybody. If you want to see examples of these, you can go to
huberman live.com and go to the menu and see newsletter. You don't have to sign up for anything to see examples of what these are. Like,
I'll provide a couple of different protocols one that is pure, static stretching
one that involves
pmf type stretching, and I'll also put down a
protocol that involves the antagonistic interleaved muscle training of the sort that I've been describing a few times throughout this episode. And then you can
Try and apply those either separately or maybe combine them in some way that's useful for your goals.
There are a couple of key elements that are essential for building a safe and
effective range of motion,
increasing program that arrived to us both through the peer reviewed research and admittedly from people that have been involved in teaching and training range of motion
for a very long period of time.
Some of you may be familiar with the so-called Anderson method. It's been
around for a long time. Actually have never met Anderson. I don't, I should know this.
Don't even know if he's still alive. I hope he's still alive.
But in any event there are a lot of different features to the Anderson and other protocols but one of the aspects of the Anderson protocol that I think is highly relevant. In fact, I know is
relevant to the peer-reviewed research that we're going to talk about in a few
moments. Is this notion of pushing through pain and how active, or how
passive to be about static
stretching. Now, this is somewhat subjective, right? If you think about getting into a stretch
again, we'll just use the hamstrings for example. So your
You're either reaching for your
toes while seated or
maybe you're using a strap and you're raising your foot over head while lying down or maybe you're doing a toe touch type
exercise. How far should you reach? Where is the
end range of motion? Should you bounce? Should you not balanced? We're going to talk a little bit
more about that in a moment. But Anderson has an interesting idea in principle which is thread through a lot of
his teachings that I
think are very much in keeping with the study that I'm
About to describe
next where he emphasizes to yes, to stretch. To the end of the range of motion, but not to focus so much on where that range of motion
happens to be that
day. So for instance, not thinking, oh, I can always touch my toes,
for instance, and
therefore, that's the starting
place for my flexibility training today.
But rather, to take the entirety of your system
into account each day and understand that. Okay?
Provided your
Warmed up appropriately. That you're now going to stretch your hamstrings for instance, and you're going to reach down for your toes but that your range of motion might be adjusted that day by way of
tension and stress or by way of ambient temperature in the
room and to basically Define the N range of motion as the place, where you can feel the stretch in the relevant muscle groups. I think this is important because unlike resistance training or cardiovascular training, where we can measure distance traveled over time in the case of
Vasco training or how much weight is on the bar and count repetitions Etc. With range of motion training, of course, range of
motion is the feature that we're interested in,
but there is likely to be a lot of
variation from day-to-day
based on a number of different internal
and external factors.
And so, the intercept method is really about getting into
static and other forms of stretching. I think, today, we mainly been focusing on static
stretching and holding the end range of motion, but really paying attention to the feel of the stretch.
Each and the muscles involved. And there are parallels in resistance
and cardiovascular training to, I realize, right in the case of trying to build
hypertrophy, or I should say improve hypertrophy, muscle size. Oftentimes the best advice that one can give is to don't try to lift weights, but rather to
challenge muscles. Now, of course, you need to provide adequate loads in order to get
hypertrophy. But when you're training purely for strength, it's about moving weights. When you're training purely for hypertrophy or mainly for hypertrophy, it's really about challenging muscles using
weights.
Other forms of resistance. And similarly and in, keeping with this Anderson method, when trying to build limb range of motion doing static stretching at a place where it's difficult, but that you can experience the stretch
of the muscle cognitively consciously being able
to focus on the
muscles and their
stretch is at least as useful as is evaluating the current range of motion. You're able to achieve. So what does this mean? This means feel the muscles as you
stretch them, don't just go.
Through the motions.
And this means don't get so attached to being able to always achieve. For instance, a stretch
of a given distance on a within a given session. You
might actually find that by just finding the place where you can't get much further and holding the static stretch, their that on the second and third set, that
you happen to be doing that day, that your range of motion will be increased considerably, maybe not but very likely. Yes, you will. And
of course, evaluating range of motion over time as
the key parameter because that's
The goal of all this type of work. Now,
along these lines, there is this variable that we mentioned a few times, a passive versus active stretching and there's this even more nebulous variable, this even more kind of subjective thing of how much effort to put into it. Should you push into the stretch? Would you even want to bounce a tiny bit? Would you want to
reach into that and point and try and extend it within a given set and session and
For that reason. I was excited to find this paper entitled. A comparison of two stretching modalities on lower. Limb range of motion measurements in recreational,
dancers happens to be done in
recreational dancers. It's a six-week Intervention Program that compared low intensity
stretching, which they call Micro stretching. They used a capital m. So I don't know if that means that its proprietary, although
I didn't see evidence of a conflict of interest but they call it micro stretching but to be very clear microstrategy
In the case of this manuscript is low-intensity stretching, and they compared that with
moderate intensity, static stretching
on an active and
passive ranges of motion. Okay, so there
are a lot of different variables are here, but I'll just highlight a few that the
things that are really most relevant to us. And I'll give you the takeaway at the outset and then return to it at the end. So that if I lose any of yours attention in the next couple of minutes, at least you have that key. Takeaway
basically, what they found was that a six-week training program.
Being very low, intensity stretching had a greater positive effect on lower limb range of motion, then did moderate-intensity static stretching. I find that incredibly interesting so very low intensity
and will Define what that means in a moment
here, I'm quoting them. The most interesting aspect of the study was the greater increase in active range of motion compared to passive range of motion by the micro stretching
group. So this relates to what we were just talking about a few moments ago
as it relates to the Anderson method, which is that
Very low, intensity stretching, meaning effort, that feels not painful and in fact might even feel easy or at least not straining to exceed a given range of motion turns out to not just be as
effective but more effective than moderate intensity stretching. So what is low intensity? Static stretching.
Well they Define this as the stretches were completed at an intensity of 30 to 40 percent.
We're 100% equals the point of pain, right? So 30 to 40% in these
individuals and again I'm paraphrasing induced a relaxed state within the individual and the specific muscle and here they were holding these static stretches, I should mention for one minute, not 30 seconds.
Now the control group was doing the exact same
overall protocol. So daily stretching for six weeks, the same exercises holding each set for 60 seconds.
But we're using an intensity of stretch of 80% where again, 100
represents the point of pain, the point where the person would want to stop stretching.
I find these data incredibly interesting, for I think
what ought to be obvious reasons.
If you're going to
embark on a flexibility and stretching training program, you
don't need to push to the point of pain. In fact, it seems that even just approaching the point of pain is going to be less
effective than operating at this 32.
40% of intensity prior to reaching that pain threshold, the pain threshold being 100%. Now of
course this is pretty subjective but I think all of us should be able to register within ourselves. So whether a given range of motion or extending a given range of motion,
brings us to that threshold of pain or near pain. And according to this study, at least
operating or performing stretching at an intensity, that's quite low.
That's very relaxing, turns out to be more beneficial.
Increasing range of motion then is doing exercises aimed at increasing range of motion at a higher intensity.
Okay, so lower intensity stretching, I
should say, lower intensity, static stretching appears to be the most beneficial way to approach stretching. And I think that's a relief. Probably too many of us because it also suggests that the injury risk is going to be lower than if one were pushing into the pain zone. So, to speak
the authors offer a number of different explanations as to why this
approach this Mike
Stretching approach might be more effective
here. I'm paraphrasing from their discussion where they mention that it could be hypothesized, that they had improved reciprocal inhibition within the hamstring muscle group. So this gets right back to the sorts of neural mechanisms that we talked about before that somehow, by doing this low-intensity stretching that they were able to access some of
those spindle and GTO type mechanisms that we were referring to earlier
and the inhibition of
hamstring and quadricep
stretches, they also offer a number of different ideas.
Is about how this could shift the activation of the so-called sympathetic.
Remember the kind of stress
division of our nervous system and to reduce that relative to activation of the
parasympathetic arm of the nervous system.
I confess, they have a couple of arguments around sympathetic parasympathetic that are somewhat convoluted. I will just In fairness to the Neuroscience. On those systems. I wouldn't suggest putting too much
weight on their arguments about sympathetic and,
Parasympathetic to my mind, they didn't really hold much water. But here I'm not trying to be disparaging of the of the overall work, which I think is really quite sound, which is that low intensity so called micro stretching is going to be the most effective way to increase limb range of movement over time. I want to just
briefly return to
this idea of whether or not to do ballistic or static stretching before some sort of skill training or weight training, or any kind of sport or even cardiovascular exercise like running
Again, the data are really split out there. There are
even folks who suggest that doing any kind of stretching prior to running is going to lower running efficiency. It's going to require essentially more work and more oxygen uptake at a given speed
for a variety of reasons and Runners. And
that Community argue about this endlessly, their papers, in both sides and both directions. I'm sure I'll hear about some of this in the comments.
I'm not really going to take a
stance on this as a consequence because the data are all over the
place. However, I think there's a general logic
that we can apply
in here. I'm borrowing from some conversations and some information put out there by dr. Andy Galpin, who I think is, of course, both an expert and thinks about these things in a really sound and flexible way. No pun intended,
there are instances. For example, where an individual might want to
do some static stretching to increase, limb range of motion prior to doing weight training.
Even if it's going to
inhibit that person's ability to lift as much weight. Why would you
Do that. Well, for instance, if somebody has a tightness or a limitation in their neuromuscular, connective tissue system someplace in their body and system that prevents them from using proper form that they can overcome by doing some static stretching. Well, that would be a great
idea as dr. Galpin points out,
or for instance, if proper
stability, within the movement requires increasing, limb range of motion in some way,
well, then compromising the use of
Of Greater loads could be greatly offset
by doing some static stretching to improve hamstring, flexibility or another muscle group flexibility.
So we can always think about just what's going to allow us or inhibit us
from using the maximum amount of weight or from
running. As far as we want to
run as fast as we want to run, there are instances where people
are trying to overcome injuries where they're trying
to come back from a reparative surgery or something of that. Sort, coming back from a layoff, where
some additional static.
In prior to cardiovascular weight training or skill training, or support of some
kind, is going to be useful because it's going to put us in a
position of Greater safety and confidence and performance, overall, even if it's adjusting down or speed or the total amount of loads that we use.
So it's you that needs to consider whether or not for you and within a given
training session, you want to do static training, I should say, static stretching range of motion training prior to or after.
That training session
and similarly,
there are a lot of data points in the fact that doing some dynamic or even
ballistic stretching, prior
to skill, training, or cardiovascular. Weight training can be beneficial in part to warm up the
relevant, neural circuits joints, and connective tissue and muscles, and as well to perhaps improve
range of motion or ability to perform those movements more accurately with more stability and therefore with more confidence and while dr. Andy Galpin.
Would never name any protocol after himself. He's far too humble to do that. I've named a couple of protocols after him particular the Galpin equation for hydration because he was willing to stick his neck out there and put down some specific numbers that people could follow in order to ensure proper hydration during training. You can look up the Galpin equation, elsewhere, you can just Google it or look
elsewhere, you'll find it and dr. Galvin is also been very thoughtful and generous and I think very
accurate in offering a kind of a general
organizational Logic for how
to think about the goals of a trick particular training session and
thereby to decide whether or not you're going to do ballistic or static stretching and so on and so forth. So we can refer to this General approach as Galpin. Nian, GAO, pinion, is that right? Galpin? Ian logic company, and logic
thus far. We've been talking about stretching
for sake of increasing, limb, flexibility and range of motion. But
There are other
reasons perhaps to embark on a stretching protocol that include both our ability to relax and access deep relaxation,
quickly, as well as even to reduce
inflammation and perhaps even combat certain forms of cancer. And if
that sounds really far-fetched want to emphasize that the study I'm about to share with you in a moment was actually carried out by one of
the directors of a division of the National Institutes of Health.
And this was
the work of helling langevin. Who's a medical doctor has done really important work on the mechanisms, underlying things like acupuncture, and has approached all that from a very
mechanistic view point, right? So not looking just at the effects of
acupuncture, but really trying to understand what sorts of
cytokines inflammatory molecules and pathways are activated, what sorts of neural
mechanisms get engaged by things like
Acupuncture that impinges on the fascial tissues and so forth
and dr. Langevin is it currently a director of
the National Institutes of contract, complementary, health and medicine at the National Institutes of Health. So this is a major division supported by tax dollars that support.
Systematic mechanistic exploration of things
like respiration meditation, yoga acupuncture.
This is serious science applied to protocols and approaches that have been used for some period of time. But really aimed
Trying to understand what would the best protocols be to evolve, new protocols. So there's a really interesting study done in animal models but I think it's a powerful enough
result that I think we all should pay attention to
it. The title of this paper and again the last author is dr. Langevin herself is stretching, reduces tumor growth in a mouse breast, cancer
model and yes you can get mice to stretch. It turns out that if you gently lift up, mice by their tail and they'll hold onto their cage. There's a, there's a way in which you can
Stretch them in a way that doesn't harm them first. I should mention that dr. Langevin, and others have shown that just a brief whole body, stretch of that
sort, induces, an increase in activation of the parasympathetic arm of the autonomic nervous system again, not
arm limb arm, but the aspect of the autonomic nervous system that creates a
whole body
whole nervous system shift toward more relaxation. So
yes, indeed stretching induces relaxation at a
Systemic level,
not just at a local level, and I think that's important, probably, not surprising to those of you that use stretching regularly, but yes, it does indeed relax us. Yes, you can do this in mice and see that in mice, as well.
Here's what they did for this current study, or I should say this was a study published in 2018 and scientific reports.
They write recent Studies have shown that, gentle daily stretching for 10 minutes. Can reduce local connective tissue, inflammation and fibrosis. Now, that's local
tissue inflammation and fibrosis as well. We now know as systemic inflammation and can induce relaxation. Systemically
in this case, they focused on mice. Not humans and mice, were randomized to a stretch versus no stretch condition and were treated for 10 minutes. Once a day for four weeks,
It's 10 minutes of this passive whole body stretching a day for four weeks. What's remarkable? I mean,
just I have to say, is just striking, is that tumor volume in these mice? They were able to induce tumors in these
mice in the tumor volume. At the end point was
52 percent smaller in the stretch
group compared to the no stretch group. This is a highly significant effect and they point
out in the absence of any other treatment
and they explored, whether or not cytotoxic to immune responses were activated.
And a number of other features. They weren't able to get too deeply into the underlying mechanisms, but this is pretty remarkable even three weeks into this stretching protocol. This daily stretching protocol for these mice
tumor volume was reduced. I mean, by, you know, it's almost half this is
pretty incredible. So, they have these measures of tumor volume, and the only difference in the way these animals were
were treated and handled. It was the introduction of this daily stretch.
I find this result to be of
Course Limited in the extent to the extent that it's done in an
animal model, not in humans, we have to point that out.
But as they point out in their discussion, our results demonstrate a 52 percent reduction. In mammary tumor growth over one month in mice undergoing stretching for 10 minutes a day without any other form of therapy. Do they think that
stretching itself is changing the tumor size? No,
in fact, they raised the possibility that stretching because of its
impact on the faccia. Might even create micro environments that are more permissive for tumor growth in certain instances.
Fences. So, they're
careful to emphasize.
What? I also believed to be the case, which is that it's unlikely that the stretching itself was directly acting to reduce tumor size.
But rather, that there is this possible link between
inflammation and immune exhaustion mechanisms that if you can periodically. Relax, a nervous system here through stretching, that it can
affect certain Pathways related to the immune system that would allow
the immune system to combat tumor growth to a significant degree. So,
Even though this is a study in mice, it argues that relaxation. Induced by stretching can have
a powerful influence on mammary tumor growth again. Huge effect carried out by one of the Premier labs, and individuals who do this sort of work and think about this sort of thing. And of course, I want to point out. It wasn't just doctor langevin. That did the study there are number of co-authors on. The study will provide a link to the coauthors. Excuse me, we will provide a link to the study so that you can peruse it in more detail if you like now as a related.
and somewhat final point, I'd like to return this to this idea and
this place this real estate within our brain that we call the insular cortex, the insula, you recall way back at the beginning of this episode, we talk about the Von Economo neurons that konstantin Von Economo, the Austrian scientist discovered
and the fact that we are able to make and perform interpretations of our
internal landscape pain,
our dedication to a practice for
Whether or not we are in pain because
it's a practice that we are doing intentionally and want to improve ourselves or whether or not it's paying that's arriving through some externally imposed demands or situations.
Well, the insula is handling all that and fortunately there's a wonderful paper that was
published as a few years ago. Now, in the journal cerebral cortex, which is a fine
Journal. This is the year. 2014 entitled insular, cortex, mediates increased pain,
tolerance in yoga practitioners? I'll tell you why. I like this.
I'm personally not a practitioner of yoga, taking a few yoga classes over the years. I've done some of the hot yoga classes, those rooms can get really, really
warm I confess.
And I've done the kind of standard yoga every now. And again, it's not something that I've kept up regularly.
This study explored the effects on brain
structure, volume in yoga practitioners. And for those of you out there that are afficionados in yoga, they they pulled
Subjects from having backgrounds in the here. I'm probably gonna mispronounce these different things in forgive me. The Vinyasa yoga is the
Ashtanga Yoga is younger. Yoga's. Sananda, yoga's. Okay? So some people were new to these practices
somewhere
experienced. That the important takeaways were that they took these yoga practitioners and they didn't explore their brain
structure in the context of yoga itself. They looked at things like pain tolerance,
so they used thermal stimulation. Basically, they put people into conditions where they
Even very hot or very cold stimuli and compared those yoga practitioners of varying levels of yoga experience to those that had no experience
with yoga. So called controls. And they found some really interesting things are a lot of data on this paper, but here's something I'd like to highlight the pain tolerance of yoga practitioners was double or more to that of non yoga practitioners. Even for those that weren't
doing the so-called Hot Yoga, right? They
also
found that pain tolerance was significantly greater both for heat pain and for cold pain. They also found significant increases in insular. Again, the insula this brain region, gray matter, volume. Typically, when we talk about gray matter, we're talking about the so-called cell
bodies, the location in neurons, where the genome is housed, and where the kind of all the housekeeping stuff is there.
And then white matter.
Volume tends to be the axons the wires because they're in sheath with this stuff that
There's white in MRIs and indeed as white Under the microscope and indeed is white. It's actually lipid, which is my land. So increased gray matter
volume of the insula
is a significant finding
because what it suggests is that people that are doing yoga have an increased volume of these areas of the brain that are associated with interoceptive awareness and for being able to make judgments
about pain and y1 is
experiencing pain, not just a lean away from pain
but to utilize or leverage or even overcome pain.
So, there are many studies of yoga and meditation out there few that have
as much mechanistic detail as this one. And in fact
there's a beautiful figure figure 3 in this paper that shows that the gray matter volume of this
particular brain region
scales in a, almost linear way, with the duration of yoga
practice that somebody has been taking on in years. So people that
had they had a few subjects that have up to
15 or 16 years of yoga practice
had much larger left insular.
A matter volume bigger brain areas associated with these abilities and I find this interesting because there are a lot of activities out there that don't create
these kind of changes in brain.
Volume is especially within the insula. So, it appears that it's not just the performance of the yogic movements, but the overcoming or the kind of pushing into the end ranges of motion and to push through discomfort to some extent. Of course,
we want people doing that in a
healthy safe way, but that's allows yoga
owners to build up the
structure and function of these brain areas that allow them to cope with pain better than other individuals and to cope with other kinds of interceptive challenges, if you will not just pain, but cold not just pain, but discomfort of being in a particular position
to do that. And again, we wouldn't want people placing themselves into a
compromised position, literally, that would harm them, especially given that earlier, we heard that micro stretching of the kind of
Painful sort low-intensity sword is actually going to be more effective for increasing n range of motion,
but this study really emphasizes the extent to which practitioners of yoga. Don't just learn movements. They learn how to control
their nervous system in ways that really reshapes their relationship
to pain to flexibility and to the kinds of things that the neuromuscular system was designed to do. And as a final point, there is a beautiful graph in this paper,
beautiful. I think, because
It explores some of the more subjective dimensions of
yoga and insular function which is a here, I'll read it out in the
nerdy form and then I'll explain what it means.
This is a frequency histogram of categories of mental strategies, used by Yogi's versus controls during the cold pain. Tolerance task. What they're describing here and showing is quantitatively how people are
conceptualizing cold pain in order to get through it
and the
And categories are for
instance, distraction?
Right. Some people just choose to
distract themselves from pain or to attempt to other people. Try to ignore it. It's a lot like distraction but nonetheless
to engage in a negative emotion, sort of, like,
like I'm going to dig. I'm gonna be in resistance to this
control subjects tended, to use those approaches where, as practitioners of yoga tended to use other sorts
of subjective approaches like positive imagery to some extent.
The ability to relax despite the extreme cold, the ability to quote unquote, except like, this is just happening despite the extreme cold to
observe to third person themselves. And the greatest effect, of course, was to breathe
to focus on their respiration as a way to deal with this challenge, this cold
challenge. Now, all of that is so our subjective data, but I want to remind you that the practitioners of yoga
Are not just using entirely different mental strategies, but they are far more
effective at dealing with pain. Their pain tolerance is much higher as evidenced by the other data in the previous graphs in the
paper. So, while this
podcast episode is most certainly not about yoga per se, it's about flexibility and
stretching flexibility and stretching our elements within yogic practices.
And of course, you'll get practices involve breathing and mental work and a lot of other things, balanced etcetera.
It's a vast landscape as many
of you know, but I think that if ever there was a manuscript that pointed to the utility
of something like yoga for sake of tapping, into a
particular set of brain circuits and
mechanisms that could Wick out into multiple dimensions of life. So day-to-day
life, stress challenges in dealing with all sorts of external,
stressors, career-related family-related, relationally, etcetera, Etc. Scuse me
But as well for increasing range of motion for increasing flexibility. So if ever, there was a practice that one could embark on
that, would not only increase flexibility and limb range of motion. But would also allow one to cultivate some improved mental functioning as it relates to pain, tolerance, and other features of Stress Management that no doubt, Wick out into other areas of
life appears that yoga is a quite useful practice. And so, for those of you that are interested in increasing, limb range of motion and you're already a
Practitioner of yoga, great, I can imagine that someday, there will be another study like
this one, and you'll be in that, you know, ten or fifteen to sixteen year practitioner graph. You'll be that dot way out on the far, end of the graph that shows that your insula is that much bigger than the rest of ours and therefore your internal awareness and pain thresholds, and Stress Management will be that much better.
But of course, yoga isn't
the only way to increase. Limb range of motion and flexibility.
Up until now we've described a number of different ways to do that. And we've arrived
at some general themes and protocols. Again, those themes and protocols will be distilled into some
specific and precise list in our neural
network newsletter. But we can revisit a
couple of them now just in summary and synthesis,
static stretching appears to be, at least among the more useful forms of stretching so low or zero momentum, stretching typically, at end range of motion, I love this concept of micro stretching.
Even though it's just a couple of studies that have addressed whether or not high intensity or low intensity static stretch holds are more beneficial, the idea and indeed the data that low-intensity so 30 to 40% of what would one would consider painful appears to be more effective than 80% of that threshold.
Find that incredibly interesting and then there's this idea of frequency, it really does appear that getting
At least 5 minutes per
week. Total of stretching for a given muscle, group is important for creating meaningful lasting changes in. Limb range of motion and that is best achieved by
five day a week or six days a week or even sit seven-day-a-week protocols. But those can be very short, protocols,
limited to say, three sets of 30, maybe even 45, or 60 seconds of static. Hold, although 30 seconds seems to be a key threshold there that can get you maximum.
Fit. There is no need to do full 60 second holds unless you're doing fewer total sessions per
week and of course always warm up or to
arrive at the stretching session warm
and then of course there are the other
forms of stretching that we touched upon a bit things like
pmf and we talked about why pmf
Works. Things like the spindle and the Golgi tendon organ reflexes that are built in to all of us that we arrived in this world with
and of course, the other forms of
stretching that are known to be effective and important such as Dynamic, and ballistic stretching.
Again stretching protocols, that involve a lot of
momentum in order to improve range
of motion for performance of particular types of work that one is about to embark on typically that would be
physical work. But a whole interesting and unexplored Landscape is the extent to which changing limb range of motion and different types of body movement,
actually shape our cognitive abilities. And that will be the topic of a future episode of this
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So thank you. Once again for joining me today. For a discussion about the neural and neuromuscular and connective tissue and
skeletal aspects of flexibility and
stretching. And as always,
thank you for your interest in science.
