back to indexImprove Flexibility with Research-Supported Stretching Protocols | Huberman Lab Podcast #76
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Welcome to the Huberman Lab Podcast,
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where we discuss science and science-based tools
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for everyday life.
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I'm Andrew Huberman, and I'm a professor of neurobiology
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and ophthalmology at Stanford School of Medicine.
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Today, we are going to discuss the science and practice
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of flexibility and stretching.
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Flexibility and stretching are topics that I believe
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do not receive nearly as much attention as they deserve.
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For most people, the topics of flexibility and stretching
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bring to mind things like yoga, injury prevention,
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or maybe even contortionism.
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But it turns out that flexibility and stretching
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are features that are built into our basic body plan.
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Young children, young animals, and adults,
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and indeed older children and animals all stretch
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and all have some degree of flexibility.
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It turns out that having flexibility and our ability
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to stretch and the interaction between stretching
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and flexibility are fundamental to how we move,
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our ability to learn new movements, indeed also
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to prevent injury or repair injuries,
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and to offsetting and reducing inflammation
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throughout the body.
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In fact, today I'm going to share with you a remarkable set
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of studies that show that stretching can actually
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adjust things like tumor growth.
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This is work that was done by one of the major directors
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of the National Institutes of Health.
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So today's discussion will start with a description
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of the mechanisms, literally the cells and the connections
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from your nervous system that mediate flexibility
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And I promise that I'll make that information accessible
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to you, whether or not you have a biology background or not.
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Then with that information in hand,
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I'm going to present to you what the scientific literature
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says about the best times and ways to stretch.
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Everything right down to the detail of how long
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to hold a stretch, whether or not to hold a stretch at all,
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because it turns out there are multiple kinds of stretching.
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So you can imagine you have stretches where you hold
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the stretch for a very long time and use as little momentum
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And then there's also what's called dynamic
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and ballistic stretching,
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where you're literally swinging your limbs,
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trying to increase the range of motion.
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I will explain the science and application of flexibility
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and stretching in the context of sports performance,
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whether or not you're engaging in cardiovascular exercise
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or resistance exercise or both,
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whether or not you're a competitive athlete
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or simply a recreational exerciser as I am,
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whether or not you are trying to increase your range
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of motion and flexibility for longevity purposes,
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or whether or not you're trying to do it in order to access
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different parts of your nervous system,
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because we'll soon learn today that your ability
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to improve flexibility and need to engage
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in specific stretching exercises can actually be used
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to powerfully modulate your ability to tolerate pain,
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both emotional and physical pain.
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So this thing that we call flexibility and stretching
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is actually a vast landscape.
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We're going to simplify and organize all that for you today.
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And by the end of today's episode,
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you're going to have a number of simple,
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easy to apply tools that are grounded
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in the best scientific research
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that you can apply for your specific goals.
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I'd like to emphasize that this podcast is separate
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from my teaching and research roles at Stanford.
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It is however, part of my desire and effort
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to bring zero cost to consumer information about science
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and science related tools to the general public.
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In keeping with that theme,
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I'd like to thank the sponsors of today's podcast.
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Our first sponsor is Thesis.
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Let's talk about flexibility and stretching.
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Before we talk about the practices
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of flexibility and stretching,
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I'd like to just highlight some of the features
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that are already built into your nervous system
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and into your body that allow you to be flexible.
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Some of us feel tighter than others,
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sometimes in specific limbs or areas of our body.
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Some people feel really loose and limber.
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Some people even have what's called a hyper flexibility.
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I, for instance, have a relative that can take her fingers
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and bend them back to the point where they touch her wrist.
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And it always makes me cringe a little bit,
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but she can do that without any pain.
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She seems to have some hyper flexibility in her joints.
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I do not have that feature.
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Some of you may find that you are more flexible
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than others naturally.
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And some of you might be thinking,
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you don't need to build in additional flexibility.
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Well, I think by the end of today's episode,
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you'll realize that almost all of us can benefit
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from having some sort of understanding about flexibility
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and having some stretching protocol
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that we incorporate into our life,
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if not just for physical performance reasons
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and for postural reasons,
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then also for cognitive and mental reasons.
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And I'll be sure to clarify what all of that means.
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Right now, I'd like to take a moment
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and just highlight the flexibility that you already have.
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For instance, if you were to move your arm
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behind your torso a little bit,
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and then sort of let go
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or stop exerting any effort in doing that,
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you would find that the limb would return
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more or less to a position next to your torso.
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At least I would hope so.
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Well, it turns out that there are aspects
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of your nervous system,
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aspects of your skeletal system,
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aspects of your muscles,
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and aspects of the connective tissue
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that binds all of that together,
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that try and restore a particular order or position
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to your limbs and your limbs relative to one another.
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So that reflects a very specific set of processes
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that it turns out are the same set of processes
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that you use when you are trying
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to enhance flexibility and stretching.
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So I'd like to just take a moment
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and review the basic elements of nervous system,
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muscle, connective tissue, and skeletal tissue, bone,
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that allow for flexibility and stretching.
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And here we can point to two major mechanisms
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by which your nervous system, neurons, meaning nerve cells,
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communicate with muscles,
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and those muscles communicate back to your nervous system
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to make sure that your limbs don't stretch too far,
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they don't move too far such that you get injured.
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And in addition to that,
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mechanisms that ensure that you don't overload your muscles
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too much with weight or with tension or with effort
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and damage them that way.
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Because it turns out that the second security mechanism
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of making sure that you don't overload muscles
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can be leveraged toward increasing your flexibility
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almost immediately.
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There are protocols and tools that I'll share with you
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that are going to allow you to vastly improve
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your flexibility over time,
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but there are also mechanisms that allow you
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to quite significantly increase your degree of flexibility
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in a very short period of time, within just a few seconds.
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So let's establish some of the basic biological mechanisms.
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In time we talk about biology or physiology,
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we're going to talk about structure,
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meaning the cells and their connections,
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and functions, what they do.
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They're just a few names to understand,
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you do not have to memorize these names.
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The important thing that I'd like you to know
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is that flexibility and the process of stretching
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and getting more flexible involves three major components.
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Neural, meaning of the nervous system,
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muscular, muscles, and connective tissue.
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Connective tissue is the stuff that surrounds
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the neural stuff and the muscular stuff,
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although it's all kind of weaved together
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and braided together in complicated ways.
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Some of you may have heard of fascia.
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We're going to talk a little bit about fascia today,
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although it's such an interesting tissue
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that's really deserving of its own episode.
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Facial tissue, we're going to talk about
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some of the stuff that surrounds muscles
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that really gives you your shape
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and holds everything together
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and allows for flexibility to occur.
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So here's a key thing that everyone should know,
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whether or not you're talking about flexibility or not.
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Your nervous system controls your muscles.
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It's what gets your muscles to contract.
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So within your spinal cord,
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you have a category of neurons, nerve cells,
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that are called motor neurons.
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To be precise, they are lower motor neurons
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because they're in your spinal cord.
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We call them lower to distinguish them
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from the motor neurons that are in your brain
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Those lower motor neurons,
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hereafter, I'll just refer to them as motor neurons.
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If I want to talk about the other kind of motor neurons,
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I'll say upper motor neurons.
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So if I say motor neurons,
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I just mean the ones in your spinal cord.
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Those motor neurons send a little wire
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or set of wires out to your muscles,
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and that creates what's called a neuromuscular junction,
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which just means that the neurons meet the muscles
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at a particular place.
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Those neurons release a chemical.
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That chemical is called acetylcholine.
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Some of you may have heard about acetylcholine before.
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Acetylcholine also exists in your brain
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and does other things in your brain.
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Mainly, it's involved in focus and attention,
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but at the neuromuscular junction,
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the release of acetylcholine from these nerve cells,
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these neurons, onto the muscles
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causes the muscles to contract.
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And when muscles contract,
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they are able to move limbs by way of changing the length
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of the muscle, adjusting the function of connective tissue,
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like tendons and ligaments.
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if you're bringing your wrist closer to your shoulder,
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that biceps muscle is contracting, it's getting shorter.
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I mean, in reality, it hasn't gotten shorter overall.
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It's just temporarily shorter, of course.
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All of that is controlled by neurons,
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and it's those motor neurons from the spinal cord
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that are really responsible for the major movement
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of your limbs by way of causing contraction
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of specific muscles at specific times.
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So the key thing to take away is that nerve controls
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the contraction of muscles.
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Now, within the muscles themselves,
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there are nerve connections,
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and these are nerve connections that arise
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from a different set of neurons in the spinal cord
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that we call sensory neurons.
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The sensory neurons exist in a different part
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of the spinal cord, and they send a little wire
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or set of wires into the muscles.
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And there's a particular kind of sensory neuron
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that comes out of your spinal cord and into your muscles,
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which are called spindle neurons.
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They create, or they actually wrap around muscle fibers,
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kind of corkscrew around them.
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They give kind of a spring-like appearance.
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If for you aficionados out there,
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these are intrafusal connections or neurons,
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intrafusal means within the muscle,
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but you really don't need to know that
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unless you're really curious about it,
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or you're going to become a neuroscientist
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or you're in medical school or something.
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These spindle connections within the muscle
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that wrap around the muscle fibers sense the stretch
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of those muscle fibers.
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So now we have two parts to the system that I've described.
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You've got motor neurons that can cause muscles to contract
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and shorten, and we have these spindles
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within the muscles themselves
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that wrap around the muscle fibers,
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and that information is sent from the muscle
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back to the spinal cord.
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It's a form of sensing what's going on in the muscle,
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much in the same way that you have neurons in your eye
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that sense light in your external environment.
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You have neurons in your ear that sense sound waves
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in your external environment.
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You have neurons in your spinal cord
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that are sensory neurons that are sensing
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the amount of stretch in the muscles.
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What happens is if a given muscle is stretching really far,
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those sensory neurons, those spindles within the muscle
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will activate and will send a electrical potential,
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literally a bit of electricity along that wire's length
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into the spinal cord, and then within the spinal cord,
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that sensory neuron communicates
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through a series of intermediate steps,
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but to the motor neuron
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and make sure that that motor neuron contracts.
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Now, why would that be useful?
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Well, what this does is it creates a situation
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where if a muscle is stretching too much
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because the range of motion of a limb is increased too much,
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then the muscle will contract
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to bring that limb range of motion into a safe range again.
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Now, what determines whether or not a range of motion
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is quote-unquote safe or not
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is dictated by a number of things.
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It's dictated by things that are happening
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in this kind of loop of neural connections
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in the spinal cord and muscle.
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It's also determined by what's going on in your head,
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literally in your mind, cognitively,
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about whether or not the movement of that limb,
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its increasing range of motion is good for you,
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whether or not you're doing it deliberately,
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whether or not it's bad for you,
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and then there are also some basic safety mechanisms
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that are put in there
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that really try and restrict our limb range of motion.
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Okay, so just to clarify,
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this whole thing looks like a loop,
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and the essential components of the loop are
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motor neurons contract muscles,
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of which there are a bunch of different varieties,
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of in this case, what we're calling the spindles,
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are sensing stretch within the muscles,
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and if a given muscle is elongating
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because of the increased range of motion of a limb,
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those sensory neurons send an electrical signal
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into the spinal cord
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such that there is an activation of the motor neuron,
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which by now should make perfect sense
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as to why that's useful.
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It then shortens up the muscle.
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It actually doesn't really shorten the muscle,
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but it contracts the muscle
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that brings the limb back into a safe range of motion.
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Okay, so this process is very fast.
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It was designed to keep your body together and safe.
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It's designed to make sure that you don't, you know,
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take your arm and swing it behind your torso,
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and it just goes all the way back to the middle of your back.
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I mean, unless you're a contortionist,
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or you've trained that kind of level of flexibility,
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that would be terrible
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because it could provide a lot of damage
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to the muscles and to the connective tissue and so forth.
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So that's one basic mechanism that we want to hold in mind,
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this idea of a spindle that senses stretch
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and can activate contraction of the muscles
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and shorten the muscles.
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The next mechanism I want to describe,
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and once again, there are only two
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that you need to hold in mind for this episode,
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this other mechanism has a lot of the same features
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as the one I just described,
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but it has less to do with stretch.
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In fact, it doesn't have to do with stretch
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as much as it has to do with sensing loads.
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So at the end of each muscles, you have tendons typically,
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and there are neurons that are closely associated
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with those tendons that are called Golgi tendon organs.
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These are neurons that are sensory neurons
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that sense how much load is on a given muscle.
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So if you're lifting up something very, very heavy,
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these neurons are going to fire,
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meaning they're going to send electrical activity
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into the spinal cord.
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And then those neurons have the ability to shut down,
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not activate, but shut down motor neurons
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and to prevent the contraction of a given muscle.
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So for instance, if you were to walk over
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and try and pick up a weight that is much too heavy for you,
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meaning you could not do it without injuring yourself
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and you start to try and heave that weight off the ground,
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there are a number of reasons why you might not be able
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to lift it, but let's say you start to get it
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a little bit off the ground,
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or you start to get some force generated
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that would allow it to move,
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but the force that you're generating could potentially
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rip your muscles or your tendons off of the bone, right?
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That it could disrupt the joints and it could tear ligaments.
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Well, you have a safety mechanism in place.
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It's these Golgi tendon organs, these GTOs as they're called
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that get activated and shut down the motor neurons
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and make it impossible for those muscles to contract.
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Okay, so on the one hand,
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we have a mechanism that senses stretch
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and can figure out when stretch is excessive
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and when the system detects that stretch is excessive,
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it activates the contraction of muscles.
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And then we have a second mechanism that senses loads.
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And when tension or loads is deemed excessive
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by these circuits,
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and remember these circuits don't have a mind.
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They don't go, oh, this is excessive.
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They just sense loads.
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And when those loads exceed a certain threshold,
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well then those GTOs, those Golgi tendon organs
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send signals into the spinal cord
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that shut down your motor neurons' ability
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to contract muscles so that you no longer
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can lift that heavy load.
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So both of these are protective mechanisms,
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but both of these can be leveraged in a very logical way
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and in a very safe way
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in order to increase your limb range of motion.
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So there are a couple of things I want to point out
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before going a little bit further
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into how your nervous system controls
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flexibility and stretching.
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And those key points are the following.
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There are now dozens, if not hundreds of studies
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that show that a dedicated stretching practice
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can improve limb range of motion.
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Now, for many of you listening, you're probably saying duh,
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but I think it's important to point that out,
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that a dedicated stretching practice
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can increase limb range of motion.
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And as you'll soon learn,
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there are specific mechanisms that can explain that effect.
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The second point is one of longevity.
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And when I say longevity,
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I don't necessarily mean late-stage aging.
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We all undergo a decrease in limb range of motion
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unless we do something to offset that decrease.
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And the current numbers vary from study to study,
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but if you look en masse, you look at all of those studies,
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and what you basically find is that
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we start to experience a decrease in flexibility
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from about age 20 until about age 49.
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That's pretty dramatic.
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And then of course it will continue after age 49,
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but basically it's a 10% decrease every 10 years.
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So we could say it's a 1% decrease per year,
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although it's not necessarily linear.
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What do I mean by that?
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Well, it's not necessarily that on your 21st birthday,
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you are 1% less flexible than you were on your 20th birthday
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and it decreased by 1% per year.
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Some of these changes can be non-linear.
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So you can imagine the person who's doing just fine
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in terms of flexibility between 20 and 30,
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and then they get to 32
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and suddenly they've lost 5% of their flexibility.
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Now, of course, there will be a ton of lifestyle factors
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if you're a regular practitioner of yoga,
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if you have a dedicated stretching practice,
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if you're doing other things
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to improve your muscle contractibility,
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so you're doing resistance training,
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it turns out can actually indirectly improve flexibility.
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There are a number of different factors,
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but the key point is that
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maintaining some degree of flexibility
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and maybe even enhancing range of motion and flexibility
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is of immense benefit for offsetting injury
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provided it's not pushed too far.
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There are a number of people
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who have pushed their limb range of motion so far
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that they experience all sorts of injuries,
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both acute and chronic injuries.
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Today, we'll also talk about how to avoid those scenarios.
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Okay, so we've established that there are mechanisms
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within the spinal cord, muscles, and connective tissue.
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Remember, it's the motor neurons, the spindles, the GTOs,
link |
and of course, the muscles themselves
link |
and connective tissue, tendons,
link |
but also other forms of connective tissue
link |
that establish whether or not a limb
link |
is going to stay within a particular range of motion or not,
link |
and whether or not a limb is going to be allowed
link |
by the nervous system to pursue or handle a given load,
link |
There are also mechanisms
link |
that arrive to the neuromuscular system
link |
from higher up in the nervous system, from the brain.
link |
And those mechanisms involve a couple of different facets
link |
that are really interesting,
link |
and I think that we should all know about.
link |
In fact, today, I'm going to teach you
link |
about a set of neurons that I'm guessing 99.9% of you
link |
have never heard of,
link |
including all you neuroscientists out there,
link |
if you're out there, and I know you're out there,
link |
that seem uniquely enriched in humans
link |
and probably perform essential roles
link |
in our ability to regulate our physiology
link |
and our emotional state.
link |
So within the brain,
link |
we have the ability to sense things in the external world,
link |
something we called exteroception,
link |
and we have the ability to sense things
link |
in our internal world, within our body,
link |
called interoception.
link |
Interoception can be the volume of food in your gut,
link |
whether or not you're experiencing any organ pain
link |
or discomfort, whether or not you feel good in your gut
link |
and in your organs,
link |
that's actually kind of feeling,
link |
mm, I feel great, I feel sated, I feel relaxed,
link |
those are all different forms of interoception.
link |
The main brain area that's associated
link |
with interpreting what's going on in our body
link |
is called the insula, I-N-S-U-L-A.
link |
It's a very interesting brain region.
link |
It's got two major parts.
link |
The front of it is mainly concerned with things like smell
link |
and to some extent, vision, and to some extent,
link |
other things that are arriving from the external world
link |
and combining with what's going on internally
link |
and making sense of all that,
link |
or at least routing that information
link |
elsewhere in your nervous system to make decision,
link |
like if you smell something good to approach it,
link |
or if you smell something bad to avoid it.
link |
The front of the insula is really doing
link |
all of that kind of stuff, along with other brain areas.
link |
The posterior insula, the back of the insula, that is,
link |
has a very interesting and distinct set of functions.
link |
The posterior insula is mainly concerned
link |
with what's going on with your somatic experience.
link |
How do you feel internally and how is the movement
link |
that you happen to be doing,
link |
combining with your internal state to allow you to feel,
link |
as I like to say, the nervous system mainly batches things
link |
into yum, like, oh, this is really good for me, yuck,
link |
this is really bad for me and I need to stop,
link |
or meh, this is kind of neutral, okay?
link |
So this isn't about food,
link |
but we could say for most stimuli, most senses,
link |
whether or not they're senses of things internally
link |
or externally, our nervous system is trying
link |
to make decisions about what to do with that information.
link |
And so it mainly batches information into yum,
link |
I want to keep doing this or approach this thing,
link |
or continue down some path of movement or eating
link |
or staying in a temperature environment, et cetera,
link |
or yuck, I need to get out of here,
link |
I don't want any more of this,
link |
I don't want to keep doing this,
link |
this is painful or aversive or stressful, and then meh.
link |
So if it doesn't really matter,
link |
I can just kind of stay right here or not.
link |
Yum, yuck, and meh.
link |
Well, in your posterior insula,
link |
you have a very interesting population
link |
of very large neurons,
link |
these are exceptionally large neurons
link |
called van economone neurons.
link |
These are neurons that are, again,
link |
unbeknownst to most neuroscientists,
link |
and they seem uniquely enriched in humans.
link |
Chimpanzees have them,
link |
and some other large animals have them.
link |
So they're found in whales, chimpanzees,
link |
elephants, and in humans.
link |
But even though we are much smaller than most whales,
link |
and even though we are much smaller than most elephants,
link |
I mean, remember there are baby elephants,
link |
as far as I know, they haven't bred up
link |
like mini elephants yet,
link |
they seem to have a teacup version
link |
of pretty much every dog breed.
link |
You can look that up,
link |
I certainly have mixed feelings about this notion
link |
of trying to downsize everything to the point
link |
where you could kind of like the pocket-sized bulldog,
link |
I think, someday will arrive.
link |
I'm not a fan of that kind of downsizing
link |
of different breeds,
link |
but because there aren't teacup elephants
link |
and teacup gorillas and teacup chimpanzees and so forth,
link |
most all of those other species are larger than us.
link |
They have these van economone neurons,
link |
and we have these van economone neurons,
link |
but we have in upwards of 80,000 of these things
link |
in our posterior insula.
link |
These other species tend to have somewhere in the range
link |
of 1,000 to maybe 10,000 or so.
link |
Why is that interesting?
link |
Well, these van economone neurons have the unique property
link |
of integrating our knowledge about our body movements,
link |
our sense of pain and discomfort,
link |
and can drive motivational processes that allow us
link |
to lean into discomfort and indeed to overcome
link |
any discomfort if we decide that the discomfort
link |
that we are experiencing is good for us
link |
or directed toward a specific goal.
link |
This knowledge turns out to be very important
link |
to keep in mind because as we migrate this conversation
link |
toward the things that we can do to enhance flexibility
link |
and stretching, you'll soon learn that there are moments
link |
within a stretching protocol where you have the opportunity
link |
to either override pain and discomfort,
link |
to kind of relax through it or push through it, right?
link |
There's a decision fork in the road there,
link |
and I'll tell you which fork in the road to take,
link |
or to say, uh-uh, I'm not going to do that.
link |
I'm going to allow these natural reflexes of the spindle
link |
to kick in and just essentially stop me from stretching
link |
if a given limb isn't designed
link |
or shouldn't be stretched that far.
link |
So I'd like you to keep these van economone neurons in mind.
link |
I should mention they're named van economone
link |
because the guy, Constantine van economone,
link |
that discovered them at the end of the 1800s, early 1900s,
link |
decided to name them after himself, as many scientists do,
link |
or certainly the neurologists and physicians are famous
link |
for naming things after themselves.
link |
These van economone neurons turn out to be very important
link |
to keep in mind as we embark on our exploration
link |
of what sorts of stretching practices can be best applied
link |
to increase flexibility, because whether or not
link |
you undertake a mild, moderate,
link |
or intense flexibility training,
link |
you will no doubt encounter a scenario at some point
link |
where you will have to ask yourself,
link |
do I quote unquote relax into this stretch,
link |
or do I try and push through just a little bit
link |
And I'll explain how to gauge that decision
link |
in a very specific and ideally safe way.
link |
And I'll give you some tools that will allow you
link |
to make that decision in the way that best preserves
link |
the integrity of those neural circuits
link |
that I described earlier and can keep you safe.
link |
These van economone neurons sit in the exact position
link |
that one would want to be able to evaluate
link |
what's going on in the body,
link |
in particular what's going on in terms of limb movements,
link |
how that relates to our feelings of discomfort.
link |
And then there's the other aspect
link |
of these van economone neurons,
link |
which is that these van economone neurons
link |
are connected to a number of different brain areas
link |
that can shift our internal state
link |
from one of so-called sympathetic activation.
link |
So this is a pattern of alertness and even stress,
link |
sometimes even panic, but typically alertness and stress
link |
to one of so-called parasympathetic activation
link |
to one of relaxation.
link |
Oftentimes you'll hear that stretching should be done
link |
by relaxing into the stretch.
link |
Well, what does it actually mean to relax into the stretch?
link |
Well, these van economone neurons sit at this junction
link |
where they're able to evaluate what's going on
link |
inside our body and allow us to access neural circuitries
link |
by which we can shift our relative level of alertness
link |
down a bit or our relative level of stress down a bit
link |
and thereby to increase so-called parasympathetic activation
link |
and to literally override some of those spindle mechanisms,
link |
even the GTO mechanisms,
link |
but especially the spindle mechanisms
link |
at the neuromuscular and musculospinal junction.
link |
And in that way, gently, subtly override the reflex
link |
that would otherwise cause us to contract those muscles back.
link |
The reason that's possible is because your brain
link |
has those other kinds of motor neurons,
link |
the upper motor neurons that can both direct,
link |
meaning control, and can override lower motor neurons.
link |
I'll give you a brief example of this
link |
that you've already done in your life
link |
and that we all have the capacity for.
link |
What I'm referring to is the monosynaptic stretch reflex.
link |
This is something that every first year
link |
neuroscience graduate student learns,
link |
which is that if you were to step on a sharp object
link |
with a bare foot, you would not need to make the decision
link |
to retract your foot.
link |
You would automatically do that
link |
provided you have a healthy nervous system.
link |
There are mechanisms in place
link |
that cause the retraction of that limb
link |
by way of ensuring that the proper muscles contract
link |
and other muscles do not contract.
link |
In fact, that they fully relax, okay?
link |
So in the case of stepping on a sharp object,
link |
like a piece of glass or a nail or a tack,
link |
you would essentially activate the hip flexor
link |
to lift up your foot as quickly as possible.
link |
In doing so, that same neural circuit
link |
would activate a contralateral,
link |
meaning opposite side of the body circuit
link |
to ensure that the leg, the foot,
link |
that's not stepping on the sharp object
link |
would do exactly the opposite and would extend
link |
to make sure that you don't fall over.
link |
All of that happens reflexively.
link |
It does not require any thought or decision-making.
link |
In fact, humans without any neocortex,
link |
literally who are discerebrate
link |
or an animal that doesn't have,
link |
and when I say discerebrate, I mean lack of cerebral cortex,
link |
they can perform that
link |
because it's all controlled by circuits
link |
that are basically below the brain and in the spinal cord.
link |
There's a little bit of activation of circuits
link |
in the kind of deeper parts of the brain,
link |
but basically you don't need to think or decide
link |
in order to do that.
link |
However, if your life depended
link |
on walking across some sharp objects,
link |
let's say, let's make it a little less dramatic
link |
so it's not like the Die Hard movie or something
link |
where he has to run barefoot across the glass,
link |
although that's a pretty good example
link |
of what I'm describing here,
link |
but let's say you had to walk across some very hot stones
link |
to get away from something that you wanted to avoid.
link |
You could override that stretch reflex
link |
by way of a decision made with your upper motor neurons,
link |
your insula, and your cognition,
link |
and almost certainly those van econimo neurons,
link |
which would be screaming,
link |
don't do this, don't do this, don't do this,
link |
could shuttle that information to brain areas
link |
that would allow you to override the reflex
link |
and essentially push through the pain
link |
and maybe even, in fact, even,
link |
not experience the pain to the same degree or even at all.
link |
So these van econimo neurons
link |
sit at a very important junction within the brain.
link |
They pay attention to what's going on in your body,
link |
pain, pleasure, et cetera,
link |
and that includes what's going on with your limbs
link |
and your limb range of motion.
link |
They also are paying attention
link |
and can control the amount of activation,
link |
kind of alertness or calmness
link |
that you are able to create within your body
link |
in response to a given sensory experience.
link |
And as I mentioned before,
link |
they seem to be uniquely enriched in humans.
link |
They seem to be related to the aspects of our evolution
link |
that allow us to make decisions
link |
about what to do with our body
link |
in ways that other animals just simply can't.
link |
Before we go any further,
link |
I want to give you a practical tool
link |
that you can, of course, use,
link |
but that will also give you insight and experience
link |
into your muscle spindle spinal cord circuit mechanisms.
link |
So what I'd like you to do
link |
is if you're in a proper place to do this,
link |
you're going to stand with legs straight,
link |
meaning knees not bent,
link |
and you're going to try and touch your toes,
link |
or for some of you, that's going to be very easy,
link |
and you might even be able to put your hands
link |
flat on the floor.
link |
I don't have that kind of flexibility.
link |
It's pretty easy for me to touch my toes.
link |
I don't care if you round your back or not,
link |
although ideally I would say don't round your back,
link |
not because it's bad to do so necessarily,
link |
but just to try and keep this the same
link |
from trial to trial, as it were.
link |
So try and get a sense of what your range of motion is
link |
in terms of bending over at the waist
link |
while maintaining a flat back
link |
and trying to touch your toes or even touch the floor.
link |
Maybe again, you can even go hands flat to the floor,
link |
maybe even far out in front of you.
link |
Okay, now what I'd like you to do is stand back up,
link |
and I'd like you to contract your quadriceps
link |
as hard as you possibly can for about five to 15 seconds,
link |
let's say 10 seconds,
link |
just to keep things more or less normalized.
link |
This obviously is not a super controlled experiment.
link |
So to contract your quadriceps, for those of you
link |
that don't know, you're going to extend your lower limb out.
link |
So this would be like kicking,
link |
although don't do it too quickly.
link |
You're going to kick out your foot.
link |
You should feel your quadriceps contract
link |
on the top of your thighs,
link |
and you're going to try and consciously contract them
link |
as hard as you can.
link |
Okay, typically if you want to point your toe
link |
back towards your knee or shin,
link |
that's also going to help somewhat
link |
to contract even harder and harder.
link |
Okay, so do that for about 10 seconds.
link |
A lot of you will do this just while standing,
link |
contract, contract, contract.
link |
Okay, then release it.
link |
And then now go ahead and repeat that stretch
link |
where you're trying to touch your toes or touch the floor.
link |
So this is again relying more or less
link |
on hamstring flexibility among other things.
link |
Okay, what most of you will find
link |
is that you have an immediate increase
link |
in hamstring flexibility,
link |
or your range of motion has increased.
link |
If you didn't experience that,
link |
then I would encourage you to try
link |
and contract your quadriceps harder and longer,
link |
so maybe 20 or 30 seconds,
link |
and then try this so-called experiment again.
link |
Why would contracting your quadriceps
link |
allow your hamstring flexibility to suddenly increase?
link |
Well, the way that our muscles are organized
link |
is such that we have muscles
link |
that are antagonistic to one another.
link |
So our quadriceps and our hamstrings
link |
work in sort of a push-pull fashion, if you will.
link |
They can antagonize one another.
link |
So when you move your heel towards your glutes,
link |
you are using your hamstring.
link |
The hamstring obviously also does other things
link |
related to hip movement.
link |
And when you lift your knee,
link |
or when you extend your foot and contract your quadriceps,
link |
you are essentially relaxing the hamstrings.
link |
Now, of course, most movements involve
link |
both quadricep and hamstring in synchrony,
link |
and that synchrony is really an elegant one,
link |
but here we're more or less isolating the quadriceps
link |
from the hamstrings, at least to the extent
link |
that it can leverage these spindle stretch mechanisms.
link |
So what happens is when you contract your quadriceps hard,
link |
you are relaxing or releasing some of the stretch
link |
that's occurring in those intrafusal spindle sensory fibers
link |
going into your spinal cord.
link |
And as a consequence, you're able then
link |
to stretch your hamstrings further,
link |
or we can be more accurate and say that your range of motion
link |
about the hamstring and its related joints is greater
link |
when you aren't engaging that spindle reflex,
link |
which would cause the hamstrings to contract, okay?
link |
So if you are somebody who has tight hamstrings,
link |
there could be a variety of reasons for that,
link |
but part of the reason is likely to be neural,
link |
and you can release that neural spindle reflex
link |
by contracting the opposite antagonistic muscle,
link |
which in this case is the quadriceps.
link |
The same thing is true and can be leveraged
link |
for stretching other muscles.
link |
So for instance, if you're going to do a tricep stretch,
link |
the typical kind of overhead where you grab your elbow
link |
and move it toward the midline of your body
link |
with the other, using your opposite hand,
link |
well, you can do that,
link |
and then I would suggest trying to flex your bicep,
link |
contract your bicep, that is, while doing that.
link |
And for most people, you'll notice a increase
link |
in the tricep range of motion or ability
link |
to kind of lean into or to relax into
link |
or to push that stretch a little bit further.
link |
Now, for you physios out there,
link |
and for those of you that have backgrounds in kinesiology,
link |
I want to acknowledge, of course,
link |
there are other mechanisms that are coming into play.
link |
There are actually neural connections
link |
within the joints themselves
link |
that are providing proprioceptive feedback,
link |
et cetera, et cetera.
link |
But this is simply to illustrate
link |
that part of our range of motion is determined
link |
by these spindle mechanisms
link |
that I spent some time focusing on earlier.
link |
And indeed, this approach can be leveraged
link |
toward creating increased limb range of motion,
link |
not just for the hamstrings, but for your quadriceps.
link |
So for instance, if you have tight quadriceps,
link |
you can do the opposite.
link |
You can contract your hamstring very intensely
link |
for let's say 10 seconds or 20 seconds or 30 seconds.
link |
So that would take some conscious effort
link |
of bringing your heel up towards your glutes.
link |
You could do that in a way
link |
that you're really trying to contract those muscles hard.
link |
You'd have to use some deliberate hamstring activation
link |
there, meaning you have to use those upper motor neurons
link |
and the other aspects of your upper brain power, as it were,
link |
to try and really contract your hamstrings
link |
as intensely as possible.
link |
Then you would relax that,
link |
and then you would do your quadricep stretch again.
link |
And if you did a pre-hamstring contraction measurement
link |
of your quadricep flexibility,
link |
and then you did a post-hamstring contraction measure
link |
of your quadricep flexibility,
link |
almost certainly you would find
link |
that that flexibility had increased.
link |
Now, of course, the muscle really didn't change much.
link |
The tendons didn't change much.
link |
What changed was the patterns of neural activation
link |
that were restricting you from, in the first case,
link |
stretching your hamstring or having a,
link |
to be more accurate, we should say,
link |
to having a certain range of motion about the hamstring
link |
and its related joints.
link |
And those break mechanisms were removed.
link |
And of course, then when you contract your hamstring,
link |
you're removing some of the neural breaks,
link |
the spindle acting as a break
link |
and inhibiting that quadricep range of motion.
link |
Okay, so you can imagine this,
link |
and in fact, you can apply this
link |
for any number of different muscles.
link |
The larger muscles and the sort of biceps, triceps,
link |
and hamstrings, quadriceps are sort of the simplest place
link |
to think about this and to apply it.
link |
But in theory, and indeed in practice,
link |
it really works for all the various muscle groups.
link |
It's just sometimes harder to access
link |
these so-called antagonistic muscle groups.
link |
Now, we should take a moment and just discuss
link |
what actually happens as we get more flexible
link |
in the short term and long term.
link |
I just mentioned what happens in the short term.
link |
Clearly, those don't involve lengthening of the muscles.
link |
It's not like the muscles slide along the bones
link |
or that the tendons really stretch out that much more
link |
than they had prior to that kind of exercise.
link |
But it is the case that if people stretch consistently
link |
over a given period of several weeks or more,
link |
that there are changes in the muscles.
link |
This gets a little bit tricky in terms of nomenclature,
link |
and I just want to highlight that
link |
because I think that a number of people get frustrated
link |
and confused, in fact,
link |
when we talk about muscles getting longer.
link |
The whole concept of a muscle getting longer
link |
isn't really in keeping with reality,
link |
but there are elements within the muscles
link |
that can change their conformation.
link |
So to get a little bit detailed here,
link |
and we won't spend too much time on this,
link |
but I just want to acknowledge this
link |
for those of you that are interested
link |
in neuromuscular physiology
link |
and how it relates to flexibility.
link |
You have your muscle fibers
link |
and then you have your so-called myofibrils.
link |
So you can imagine kind of a single fiber.
link |
That fiber, of course,
link |
will get input from those motor neurons.
link |
And then within those fibers,
link |
you have what are called sarcomeres.
link |
And you can kind of think about sarcomeres
link |
as little segments, kind of like the segments of bamboo.
link |
If you ever look at bamboo, it's not just one big stalk.
link |
It's got those little out pouchings along the way
link |
that kind of break up what would be
link |
just one big stalk of bamboo into different segments,
link |
but they're all connected.
link |
The sarcomeres are somewhat like that.
link |
And within the sarcomeres,
link |
you have a couple of different components.
link |
One thing is called myosin, which is like a thick layer,
link |
and then the other is actin.
link |
And those are interdigitated, as we say.
link |
They're kind of connected to one another,
link |
kind of like if you put your fingers together
link |
from your two hands,
link |
if you put your fingers in between one another,
link |
that's interdigitate, literally interdigitate in this case.
link |
And the myosin and actin kind of move relative
link |
to one another, and they have a lot to do
link |
with your ability to contract muscles.
link |
When we stretch muscles,
link |
when we go through a stretching practice,
link |
there are a number of things that change, some neural,
link |
some related directly to connective tissue,
link |
but also it appears from really nice work,
link |
mainly done from McGill University.
link |
I'll provide a link to a couple of these studies
link |
if you want to dig in there more deeply,
link |
that change the conformation,
link |
the relative size and spacing of some of these things
link |
like sarcomeres and the way that myosin and actin
link |
kind of work together.
link |
But we don't want to think of muscles as lengthening.
link |
We can, however, think about the resting state of a muscle
link |
being slightly different or indeed very different
link |
than the resting state of a muscle of somebody
link |
or of a limb that has not undergone
link |
regular flexibility training.
link |
So that's as much time as I want to spend on that
link |
because we could spend an entire hour
link |
getting right down into the details.
link |
But I do want to emphasize, however,
link |
that muscles have different parts.
link |
They have fibers, they have sarcomeres,
link |
they have myosin, they have actin.
link |
But the idea of making our muscles longer,
link |
that reflects a number of processes that occur
link |
basically within an existing muscle length.
link |
The length of our muscle bellies
link |
and where our insertions are relative
link |
to our connective tissue in our limbs
link |
is genetically determined, right?
link |
Some people have, for instance,
link |
a bicep that goes all the way from the crook of their elbow
link |
up to their shoulder, right?
link |
And some people can, you know,
link |
if they were to put their arm at a 90 degree angle,
link |
could put two or three fingers
link |
between their bicep and their elbow.
link |
They have a, we can say, a shorter bicep, relatively shorter.
link |
Now, the reason I mention
link |
these highly detailed cellular mechanisms
link |
is because as we start to embark on different protocols
link |
for using stretching to increase flexibility
link |
and range of motion,
link |
we need to ask ourselves,
link |
what is preventing our ability to extend range of motion?
link |
Is it the spindle, right?
link |
Is it because the muscle is stretching too much?
link |
Oftentimes it can be because of that
link |
and or because of a sense of pain
link |
or simply a sense that the muscle is not in a position
link |
that it's been in before
link |
that's unrelated to pain or to spindle activation.
link |
And oftentimes it can be related directly
link |
to these changes in the confirmation of myosin and actin
link |
and within the context of the sarcomeres.
link |
Now, of course you can't peer into
link |
or sense your individual sarcomeres.
link |
However, you do have neurons that innervate these areas
link |
and that send that sensory information
link |
back into the spinal cord
link |
and up to your brain to interpret.
link |
So you'll find that as we move along,
link |
there are specific adjustments that you can make
link |
at both the macro level,
link |
meaning how much movement to insert into your stretching,
link |
right, is it going to be a static or dynamic
link |
or even a ballistic stretch?
link |
Or for instance, at the micro level
link |
that even just a slight sub millimeter or millimeter increase
link |
in the stretching of a given muscle and related tissues
link |
can translate into an increased range of motion performance.
link |
As a quick but relevant aside,
link |
I thought I'd share with you something useful
link |
that's also grounded in this notion
link |
of antagonistic muscles.
link |
So for those of you that do resistance training,
link |
whether or not it's with body weight
link |
or with physical weights or machines, what have you,
link |
you may have found that if you,
link |
let's say were to do three sets of a pushing exercise,
link |
so this could be pushups, this could be bench presses,
link |
this could be shoulder presses, something of that sort.
link |
And then later in the workout, you were to do,
link |
let's say machine pull downs or pull ups
link |
or chin ups of some sort, so a pulling exercise.
link |
Typically what you would find is if you were to do
link |
what's often called straight sets,
link |
so you would do three sets of pushups,
link |
let's say with two minutes of rest in between,
link |
that you might be able to get a certain number
link |
of repetitions on the first set.
link |
Just for sake of example, let's say you can get
link |
10 repetitions on the first set,
link |
and then you get eight repetitions on the second set,
link |
and then you get six repetitions on the third set
link |
with two minutes in between.
link |
And then you would move on at some point
link |
to your pulling exercises.
link |
And similarly, let's say you were doing chin ups
link |
or pull downs, and you would get 10 repetitions,
link |
rest two minutes, eight repetitions,
link |
rest two minutes and six repetitions.
link |
Well, typically what people discover
link |
is that if they interleave their pushing
link |
and pulling exercises, provided they do that
link |
for muscles that are antagonistic to one another,
link |
so in this case, pushing with the chest,
link |
shoulders and triceps for the pushing exercises
link |
and pulling with the back and biceps,
link |
and of course there are other muscles involved as well,
link |
but because those muscle groups are at least
link |
in part antagonistic to one another,
link |
what people often find is that if they were to say,
link |
do their pushing set, get 10 repetitions,
link |
then move to a pulling set after just say 60 seconds
link |
and perform that pulling set,
link |
then go back to the pushing set,
link |
then go back to a pulling set, push, pull, push, pull,
link |
in other words, interleaving their sets,
link |
even if they were to maintain the same amount of rest
link |
between sets of pushing and sets of pulling,
link |
what they discover often is that the drop
link |
in the number of repetitions that they get
link |
is somewhat offset, so rather than get 10, eight, six,
link |
as it were with the straight sets, it will be 10, nine, eight.
link |
So what this means is not that you're increasing
link |
the total rest time to four minutes between sets,
link |
because then of course it wouldn't be equivalent,
link |
but rather that while maintaining the same amount of rest
link |
between sets for this same muscle group,
link |
by going from push, pull, push, pull
link |
of antagonistic muscles,
link |
you're able to have improved performance.
link |
And the reason for that has everything to do
link |
with what we were describing before,
link |
which is that typically if you were to do push set,
link |
rest, push set, rest, push set, rest,
link |
well, in between those sets,
link |
and in fact, actually during those sets of pushing,
link |
the pulling muscles that would be involved
link |
in the chin ups or pull downs, et cetera,
link |
are actually relaxing,
link |
or at least are being released of some tension,
link |
including the activation of the spindles,
link |
among other things.
link |
So that's a long-winded way of saying
link |
that interleaving push and pull of antagonistic sets
link |
can leverage some of the same neural circuits
link |
that we're talking about leveraging
link |
for sake of increasing flexibility.
link |
Now, I offer this to you as a tool that you can try.
link |
One of the challenges with using this tool, however,
link |
is that you often have to occupy multiple sites
link |
If you're doing this at home and you have your own gym,
link |
If you're doing this in a gym
link |
where you have multiple pieces of equipment,
link |
well, then you become that person
link |
who has essentially taken over some small corner
link |
or multiple corners or machines within the gym.
link |
And oftentimes you'll find that you'll walk back
link |
to a machine or you'll walk back
link |
to a given resistance exercise and someone has now taken it
link |
over and the whole thing could be thrown off.
link |
So it takes a little bit of orchestrating
link |
in order to do properly.
link |
But in general, what people find is that this can allow you
link |
to enhance performance overall of these individual movements
link |
again, while maintaining the same amount of rest.
link |
And even if you choose not to do this,
link |
I encourage you to pay attention to this as a concept
link |
because again, it's leveraging this idea
link |
of antagonistic muscles, flexors and extensors,
link |
antagonistic neural relationships
link |
between the spinal cord mechanisms
link |
that control one set of muscles
link |
and activating those muscles,
link |
allowing the opposite antagonistic muscle to relax
link |
and therefore to perform better on its next set.
link |
So now I'd like to shift to the question
link |
of what types of stretching can and should we do
link |
to increase limb range of motion?
link |
If our goal is to do that in the most efficient way possible
link |
because I realized that most people don't have
link |
endless amounts of time to dedicate to a stretching practice
link |
and even for those of us that do,
link |
I'm sure that you want to get the most outcome
link |
for a given effort.
link |
And what are the modes of stretching
link |
that are going to allow us to increase our flexibility
link |
and limb range of motion most safely?
link |
Now, there are a number of different types of stretching
link |
or methods of stretching.
link |
Broadly defined, we can describe these as dynamic,
link |
ballistic, static, and what's called PNF stretching.
link |
PNF stands for proprioceptive neuromuscular facilitation,
link |
and it involves and leverages many of the mechanisms
link |
that I described to you earlier.
link |
The first two that I mentioned,
link |
dynamic and ballistic stretching,
link |
both involve some degree of momentum
link |
and can be distinguished from static and PNF type stretching.
link |
Now, to distinguish dynamic stretching
link |
from ballistic stretching,
link |
like to focus on this element of momentum.
link |
Both involve moving a limb through a given range of motion.
link |
In dynamic stretching, however,
link |
it tends to be more controlled, less use of momentum,
link |
especially towards the end range of motion.
link |
Whereas in ballistic stretching,
link |
there tends to be a bit more swinging of the limb
link |
or use of momentum.
link |
So I invite you to visualize what dynamic
link |
and ballistic stretching might look like in your mind.
link |
You can even try it if it's safe for you to try it.
link |
You could imagine swinging your arm up overhead
link |
as much as possible and bringing it down.
link |
I'm doing this because I'm seated
link |
as kind of ridiculous movement to do while seated
link |
or perhaps at all.
link |
But for instance, you can see dynamic
link |
and ballistic stretching anytime someone, for instance,
link |
is holding onto something with one arm
link |
or maybe not holding on and swinging out their foot.
link |
So essentially getting movement about the hip joint.
link |
And you'll notice that some people raise it up and pause it
link |
and bring it down.
link |
That's one form of dynamic stretching.
link |
Whereas others will swing it up
link |
and sort of let it carry itself a bit further
link |
due to the momentum at the top of the movement
link |
and then just let it drop back down
link |
or maybe even control the descent.
link |
There is an enormous range of parameter space here
link |
or variables that one could imagine.
link |
And there's just simply no way
link |
that we could subdivide all those.
link |
But again, dynamic and ballistic stretching
link |
both involve movement.
link |
So we have to generate some force
link |
in order to create that movement.
link |
Ballistic stretching involving a bit more momentum
link |
or sometimes a lot more momentum
link |
especially at the end range of motion.
link |
Now, both of those are highly distinct
link |
from static stretching
link |
which involves holding the end range of motion.
link |
So minimizing the amount of momentum that's used.
link |
So to stay with a simple example
link |
that we are all now familiar with
link |
from our earlier discussion,
link |
slowly bending over at the waist
link |
and trying to touch your toes
link |
or putting your hands to the floor
link |
and then holding that end position
link |
before coming up in a slow and controlled way
link |
such that you reduce the amount of momentum to near zero
link |
would be one example of static stretching.
link |
Static stretching can be further subdivided
link |
into active or passive, right?
link |
There are different names for these kinds of approaches.
link |
You can hear about the Anderson approach
link |
or the Jonda approach.
link |
You can look these sorts of things up online.
link |
And again, people tend to name things after themselves.
link |
So some of these are proprietary
link |
related to specific programs.
link |
I'm not focusing on those.
link |
Others come to be named after the physiologists
link |
or the practitioners that initially popularized them.
link |
As is always the case,
link |
there's always a naming and renaming
link |
and claiming of territory with these things.
link |
For the time being,
link |
I'd like to just emphasize that static stretching
link |
can be both active
link |
where there's a dedicated effort
link |
on the part of the stretcher, you,
link |
to put force behind the hold to kind of extend
link |
or literally to extend the range of motion.
link |
And then there's also passive static stretching
link |
in which it's more of a relaxation
link |
into a further range of motion.
link |
And that can be a subtle distinction.
link |
And there are other ways in which we can further distinguish
link |
active and passive static stretching.
link |
But nonetheless, static stretching involves
link |
both those types of elements, active and passive,
link |
but is really about eliminating momentum.
link |
And then there's the PNF,
link |
the proprioceptive neuromuscular facilitation.
link |
And proprioception has several different meanings
link |
in the context of neuroscience and physiology
link |
to just keep it really simple for today.
link |
Proprioception involves both a knowledge and understanding
link |
of where our limbs are in space and relative to our body,
link |
typically relative to the midline.
link |
So the brain is often trying to figure out
link |
where are our limbs relative to our midline
link |
down the center of our body.
link |
And we know where our limbs are
link |
based on so-called proprioceptive feedback.
link |
So that's feedback that comes from sensory neurons, right?
link |
Now you know what sensory neurons
link |
that are essentially monitoring or responding to
link |
events within the joints,
link |
the connective tissue and the muscles,
link |
and within the deep components of the muscles,
link |
like the spindle reflex,
link |
and within the tendons like the GTO,
link |
the Golgi tendon organ.
link |
So PNF type stretching leverages these sorts of mechanisms,
link |
these neural circuits by way of, for instance,
link |
you would lie on your back.
link |
And if your goal is to increase your hamstring flexibility
link |
and the flexibility and range of motion
link |
of other related muscle systems,
link |
you might put a strap around your ankle
link |
and pull that muscle, or I should say, excuse me,
link |
that limb towards you.
link |
You're not going to pull the muscle towards you.
link |
You're going to pull that limb, your ankle towards you
link |
to try and get it sort of back over your head,
link |
and then progressively relaxing into that,
link |
or maybe even putting some additional force
link |
to push the end range of motion and then relaxing it,
link |
and then actually trying to stretch that same limb
link |
or increase the limb range of motion without the strap,
link |
Sometimes these are assisted by other people.
link |
So people will even use loads.
link |
Sometimes they'll even use machines.
link |
There are a number of different apparati
link |
that have been designed for this.
link |
Sometimes it'll involve a training partner.
link |
There's a huge range of PNF protocols,
link |
and those protocols can be done both by oneself
link |
with or without straps, with machines, with actual weights,
link |
or with training partners.
link |
If you're interested in the variation of exercises
link |
to say target your hamstrings versus your quadriceps
link |
versus your shoulders versus your chest muscles, et cetera,
link |
your neck muscles, and so on,
link |
there is an enormous range of information on dynamic,
link |
ballistic, static, and PNF stretches
link |
for all the various muscle groups.
link |
And I should say there are some excellent books
link |
There are also some excellent videos on YouTube
link |
Nowadays, it's pretty easy to find exercises
link |
that allow you to target specific muscle groups.
link |
Again, I encourage you to be safe in how you approach this,
link |
and I would encourage you also to pay attention
link |
to the information that soon follows
link |
as to what sorts of protocols one would use
link |
to apply those exercises.
link |
But the number of exercises and the availability
link |
of those exercises for targeting different muscle groups
link |
with these four different kinds of stretching
link |
is both immense and fortunately, thankfully,
link |
immediately accessible to all of us, often at zero cost.
link |
So specific exercises to target specific muscle groups
link |
aside, we've now established that there are
link |
four major categories of stretching,
link |
or at least those are the four major categories
link |
I'm defining today, and we can further divide
link |
those categories into which are the ones
link |
that are going to be most effective
link |
for increasing range of motion in the long-term,
link |
not just in one individual session.
link |
And there've been a number of studies exploring this.
link |
I can list out at least four, and we'll put those four
link |
as a kind of a cluster under one heading
link |
in the show note captions that arrive
link |
at essentially the same answer,
link |
which is that for increasing limb range of motion,
link |
it does appear that static type, including PNF,
link |
but static type stretching is going to be more effective
link |
than dynamic and ballistic stretching.
link |
So at least to my mind, this is good news.
link |
Why is it good news to me?
link |
Well, while dynamic and ballistic stretching
link |
can be immensely useful for improving performance
link |
of specific movements, in particular,
link |
in the context of particular sports like tennis
link |
or in sprinting, or frankly, for any sport,
link |
they do carry with them a certain amount of risk
link |
because of the use of momentum.
link |
So you don't need to be highly trained
link |
in order to perform them.
link |
In fact, there is a place, and we will describe
link |
when one would want to apply dynamic
link |
or ballistic stretching.
link |
I'll just give away for now,
link |
I think that most physios out there,
link |
and certainly the ones that I spoke to Dr. Andy Galpin,
link |
Dr. Kelly Starrett, and a few others point to the fact
link |
that doing some safe dynamic and ballistic stretching
link |
prior to say a resistance training session,
link |
or maybe even prior to a cardiovascular training session
link |
can be useful, both in terms of range of motion effects
link |
and in terms of neural activation effects.
link |
I don't want to use the words warm up
link |
because warming up is typically associated
link |
with increasing core body temperature, as it should be,
link |
but for engaging the neural circuits
link |
and becoming familiarized with the neural circuits
link |
that you're about to use in other movements,
link |
while also increasing the range of motion
link |
of the joints involved in those movements
link |
so that you can perform them more safely
link |
and more confidently.
link |
So I'm certainly not saying, I want to repeat,
link |
I'm certainly not saying that dynamic
link |
and ballistic stretching are not useful.
link |
They absolutely are.
link |
But in terms of increasing limb range of motion
link |
in the longterm of truly becoming more flexible
link |
as opposed to transiently more flexible,
link |
static stretching, which includes PNF,
link |
appears to be the best route to go.
link |
So if your goal is to increase your limb range of motion
link |
for a given muscle group, or perhaps for all muscle groups,
link |
although you can imagine that'd be pretty tough.
link |
I mean, you're not going to spend time,
link |
I could imagine working on your tongue muscle control
link |
or neck muscle control and every muscle control,
link |
but most of us want to reduce so-called tightness,
link |
in air quotes, and increase limb range of motion
link |
for certain muscle groups.
link |
And it appears that the best way to do that
link |
is going to be static stretching of some kind,
link |
which raises the question of how often
link |
to do that static stretching
link |
and how long to hold those static stretches.
link |
And we can also ask the question,
link |
we should ask the question,
link |
where to hold those static stretches?
link |
Is it always a good idea to hold those static stretches
link |
at the end or the point of maximal range of motion?
link |
We're going to address that now.
link |
There's some terrific science around this.
link |
A slightly older study, but nonetheless, a powerful one,
link |
because it provided a foundation
link |
for a lot of subsequent work,
link |
which basically served to just confirm
link |
the answer they got here,
link |
is a study from Bandy et al, and the title of this study
link |
is The Effect of Time and Frequency of Static Stretching
link |
on the Flexibility of the Hamstring Muscles.
link |
It was a study involving 93 subjects,
link |
so 61 men, 32 women, ranging in age from 21 to 39 years,
link |
so a pretty broad demographic,
link |
who had limited hamstring muscle flexibility,
link |
here I'm paraphrasing,
link |
and randomly assigned to one of five groups.
link |
So the four stretching groups stretched five days per week
link |
The fifth group, which served as a control, did not stretch.
link |
The results clearly show that, quote,
link |
"'The change in flexibility' appeared to be dependent
link |
on the duration and frequency of stretching."
link |
This tells us that stretching for a given amount of time
link |
scales with the amount of limb range of motion improvement
link |
that one will see.
link |
There were many interesting findings within this study,
link |
but the one that I'd like to highlight most is, quote,
link |
"'The results of this study suggest
link |
that a 30-second duration is an effective amount of time
link |
to sustain a hamstring muscle stretch
link |
in order to increase range of motion.
link |
No increase in flexibility occurred
link |
when the duration of stretching was increased
link |
from 30 seconds to 60 seconds,
link |
or when the frequency of stretching was increased
link |
from one to three times per day."
link |
Okay, so now we're starting to lay down some parameters.
link |
What this study reveals and what subsequent studies tell us,
link |
and we will get into those subsequent studies,
link |
is that ideally one would do static stretches
link |
that are held for 30 seconds,
link |
perhaps more in certain instances,
link |
and I'll explain when that can be useful,
link |
but here, holding those stretches for more than 30 seconds
link |
did not turn out to be additionally useful.
link |
So if you're going to stretch your quadricep, for instance,
link |
and you're going to hold that stretch in static fashion,
link |
remember, not using momentum,
link |
and you can use the mental tricks
link |
of either trying to push through the pain,
link |
which I don't recommend necessarily,
link |
I think that makes us prone to injury,
link |
or to relax into the stretch,
link |
but nonetheless, providing some force,
link |
typically with a hand in order to pull your ankle back,
link |
if you're doing a quadricep stretch,
link |
some people might do this on the edge of a sofa.
link |
Remember, there are a lot of different exercises
link |
and ways to do this that you can explore elsewhere.
link |
Well, holding that static stretch for 30 seconds
link |
appears to be sufficient to stimulate an increase
link |
in limb range of motion over time.
link |
Again, these are protocols
link |
that were used repeatedly over time,
link |
and we'll talk about how often to repeat them
link |
in order to get maximum effect,
link |
but 30-second holds for static stretches
link |
is the number that I think we want to focus on
link |
and that most of us are going to want to utilize.
link |
So now let's explore how many sets of static stretching
link |
one ought to do in order to get
link |
a maximum range of motion improvement
link |
while not placing us into a system
link |
that's going to create injury,
link |
nor a situation where we have to be
link |
constantly stretching throughout the day,
link |
because again, most of us don't have time to do that.
link |
This issue of sets is an important one.
link |
In the context of cardiovascular exercise,
link |
we've talked about the data that support the fact that
link |
doing at least 150 and ideally
link |
as much as 200 minutes per week
link |
of zone two cardiovascular exercise
link |
is very useful for cardiovascular health
link |
and for other aspects of health.
link |
And of course, there are other aspects
link |
of cardiovascular exercise
link |
that could be layered onto and into that
link |
that can be useful like 90-second maximal sprints, et cetera.
link |
Discuss this a lot in the episode with Dr. Andy Galpin
link |
and on our episode about endurance.
link |
And we also talked about sets
link |
in the context of strength and hypertrophy building,
link |
building muscle size and or strength
link |
in the episode about that
link |
and in particular in the episode with Dr. Andy Galpin.
link |
And there, we could also arrive at some specific parameters
link |
and it's going to vary, of course, between individuals,
link |
depending on how hard you train,
link |
whether or not you take sets to failure,
link |
your repetition range, et cetera.
link |
But in the context of strength and hypertrophy building,
link |
we arrived at approximately six,
link |
maybe as many as 10 sets per week per muscle group,
link |
some of that work is done as direct work
link |
to a given muscle group, some of that work is indirect.
link |
So doing a certain pulling exercise, of course,
link |
will target the latissimus dorsi muscles,
link |
but also the biceps.
link |
So that doesn't necessarily mean you have to do 10 sets
link |
for the biceps and for the lats.
link |
Sometimes you're getting some indirect work, et cetera.
link |
All of that was delineated in the episode
link |
with Dr. Andy Galpin.
link |
And we arrived at those numbers of sets
link |
according to the same criteria that we will apply here.
link |
What is the minimum number of sets both to maintain
link |
and to improve a given mode of performance?
link |
Strength and hypertrophy or cardiovascular health.
link |
Again, to either maintain or improve.
link |
And we can do the same thing for improving
link |
or maintaining range of motion.
link |
Because as I mentioned earlier,
link |
the data points to the fact that if we don't do
link |
some dedicated work to improve range of motion over time,
link |
we will lose our flexibility and limb range of motion
link |
over time just by virtue of the fact
link |
that we're not doing anything to offset that.
link |
So whether or not you want to maintain, reestablish,
link |
or gain limb range of motion,
link |
static stretching of holds of 30 seconds appear to be best.
link |
Now the question is, how long should you do that?
link |
And how many sets should you do that?
link |
And how many times a week should you do that?
link |
And to answer those questions,
link |
I'm going to turn to what I think
link |
is a really spectacular review.
link |
This was a review that was published in the year 2018.
link |
So it's fairly recent.
link |
First author, Thomas, Edwin Thomas, last author, Palma.
link |
We will put a link to this in the show note caption.
link |
The title of the paper is the relation
link |
between stretching typology and stretching duration,
link |
the effects on range of motion.
link |
It's a very straightforward title.
link |
This is a review article that explored
link |
a number of different studies,
link |
had criteria for whether or not those studies
link |
could be evaluated in the context of the questions here,
link |
had some quality standards and some other standards
link |
that they applied,
link |
and basically winnowed down a large collection of studies
link |
to a remaining 23 articles
link |
that were able to be considered, quote,
link |
eligible and included in the quantitative synthesis
link |
So key points from that quantification and synthesis
link |
done in this paper.
link |
First of all, and I quote,
link |
all stretching typologies showed range of motion improvements
link |
over a long-term period.
link |
However, the static protocols showed significant gains
link |
with a P value less than 0.05,
link |
which means a probability that cannot be explained
link |
by chance alone when compared to ballistic
link |
So again, what we're hearing is that static stretching
link |
is the preferred mode for increasing limb range of motion.
link |
Although here they make the additional point
link |
that static stretching might even be superior,
link |
not just to ballistic stretching,
link |
but also to PNF protocols.
link |
Because before, as you may recall,
link |
there was a distinction between ballistic and dynamic
link |
and static and PNF.
link |
And so here, it appears again,
link |
that static stretching is sort of rising
link |
to the top of the list as the optimal approach
link |
relative to all other stretching approaches,
link |
at least in the context of increasing limb range of motion.
link |
The authors go on to say time spent stretching per week
link |
seems fundamental to elicit range of movement improvements
link |
when stretches are applied for at least
link |
or more than five minutes per week.
link |
Okay, this is critical.
link |
This is not five minutes per stretch.
link |
Remember, 30 seconds per static stretch,
link |
but at least five minutes per week.
link |
Whereas the time spent stretching within a single session
link |
does not seem to have a significant effects
link |
for range of motion gains.
link |
If this is getting confusing,
link |
I'll make sure that you soon understand
link |
exactly what we can export from these conclusions.
link |
The data indicate that performing stretching
link |
at least five days a week.
link |
Now, some of you may already be groaning
link |
for at least five minutes per week.
link |
Okay, so five days per week, that's a lot,
link |
but at least five minutes per week,
link |
five minutes per week is not that much.
link |
Using static stretching may be beneficial
link |
to promote range of motion improvements.
link |
Okay, I've read this study in detail now.
link |
They highlight, again, the reduction in flexibility
link |
that occurs from 20 to 49 years of age and so on,
link |
how acute bouts of short-term stretching
link |
up to three weeks can improve stretch tolerance.
link |
I think that's a key point that in the short term,
link |
the first three weeks of embarking
link |
on a stretching and flexibility program,
link |
much of the improvements come
link |
from the short-term neural improvements
link |
that we talked about before
link |
of inhibiting the spindle reflex and so on,
link |
and also a stretch tolerance,
link |
a comfort with doing the movements
link |
and maybe even a comfort in overriding
link |
some of the pain mechanisms.
link |
I'll talk a little bit more about that in just a bit
link |
and the particular utility of yoga,
link |
something that I don't often practice,
link |
but that after reading this article
link |
that I'll mention in a little bit,
link |
I'm considering perhaps taking up
link |
some form of yoga protocol.
link |
Now, I've already highlighted some of the key takeaways
link |
from the study, namely that we need to get
link |
at least five minutes per week
link |
of static stretching per muscle group.
link |
And based on the previous paper that we talked about,
link |
we need to divide that five minutes
link |
into sets of 30 seconds each.
link |
And as I mentioned earlier,
link |
it doesn't seem to be the case
link |
that you can do all of that in one day, unfortunately.
link |
It does seem important that the frequency
link |
of stretching practice distributed
link |
throughout the week is important.
link |
So let's talk protocols.
link |
We are now talking about doing static stretching,
link |
so holding, so limiting momentum
link |
and holding a stretch for 30 seconds per set.
link |
We're talking about trying to achieve five minutes per week
link |
of those static holds,
link |
but that we can't do it all in one session
link |
because the frequency of sessions distributed
link |
throughout the week correlates
link |
with the improvements in limb range of motion.
link |
So what this means is that we should probably be doing
link |
anywhere from two to four sets
link |
of 30 second static hold stretches,
link |
five days per week, or some variant thereof.
link |
And I do say some variant thereof,
link |
because it turns out that even though there was
link |
that earlier study that we talked about,
link |
that holding a stretch for more than 30 seconds,
link |
in that case, 60 seconds,
link |
didn't turn out to be additionally beneficial.
link |
It appears that if you do hold those stretches
link |
for 60 seconds per static stretching set, for instance,
link |
you can get away with stretching fewer days per week overall.
link |
So in order to make this as clear as possible,
link |
because I do realize there are a lot of parameters,
link |
and you might be asking,
link |
why didn't you just make me a list
link |
of the exact things I should do?
link |
Well, it doesn't work that way
link |
because once you understand the mechanisms
link |
and once you understand your particular goals,
link |
this information is designed for you to be able
link |
to construct a stretching program
link |
that is tailored to your specific goals.
link |
If I just gave you the stretching program that I'm doing,
link |
or I should say that I'm soon to be doing,
link |
because I'm soon to be doing one based on the research
link |
for this particular episode,
link |
well, that wouldn't be beneficial for you.
link |
Because for instance, if you have very flexible hamstrings,
link |
but not very flexible quadriceps,
link |
or you are somebody who is engaged in sport
link |
or not engaged in sport,
link |
what you need to do is going to vary somewhat.
link |
So what would effective stretching protocol look like?
link |
We're all trying to improve limb range of motion
link |
for different limbs and different muscle groups,
link |
but just by way of example,
link |
and that's because the one we've been using,
link |
let's talk about hamstrings for the time being.
link |
This could of course be applied to other muscle groups.
link |
Let's say you want to improve hamstring flexibility
link |
and limb range of motion about and around the hamstring
link |
and involving the hamstring.
link |
You would want to do three sets
link |
of static stretching for the hamstring.
link |
Again, easy to find such exercises on the internet.
link |
You would do that by holding the stretch for 30 seconds,
link |
resting some period of time and doing it again,
link |
holding for 30 seconds, resting some period of time,
link |
and then holding it for 30 seconds.
link |
That would be one training session for the hamstrings.
link |
I have to imagine that you'd probably want to stretch
link |
other muscle groups as well in that same session.
link |
Although at least as far as I could tell,
link |
there were no data pointing to the fact
link |
that you couldn't do your hamstring stretching
link |
one part of the day
link |
and your quadriceps stretching another part of the day,
link |
but presumably you're going to want to combine
link |
your flexibility training into one single session.
link |
So three sets of 30 seconds each, get 90 seconds,
link |
and you would do that ideally five times a week,
link |
or maybe even more, because it does seem like frequency
link |
distributed throughout the week is an important parameter.
link |
Now, one thing that we have not highlighted
link |
or at least described is how long to rest
link |
between stretching sets.
link |
And despite my efforts,
link |
I could not find research back information
link |
that pointed to whether or not 30 seconds of rest
link |
for every 30 seconds stretching
link |
or 60 seconds rest for every 30 seconds stretching
link |
I think it's reasonable to assume that
link |
doubling the amount of time for the interleaving rest
link |
would be appropriate or at least doable.
link |
If anyone out there has knowledge about
link |
rest between stretching sets and has some physiology
link |
or some biology or some experiential information
link |
as to why a given ratio of duration of static stretch
link |
to rest in between static stretch sets ought to be used,
link |
please put it in the comments on YouTube.
link |
That'd be a terrific way for us to get that information.
link |
I'd love to do any follow-up to links that you provide
link |
But now we're starting to build into a protocol
link |
that is backed by the scientific data.
link |
Three sets of 30 seconds of holds done five times
link |
or maybe even six times per week.
link |
One thing that did show up in my exploration
link |
of the peer-reviewed research
link |
is this notion of warming up for all this.
link |
We haven't talked about that yet.
link |
In general, to avoid injury,
link |
it's a good idea to raise your core body temperature a bit
link |
before doing these kinds of stretches,
link |
even these static stretches,
link |
which we can sort of ease into
link |
and don't involve ballistic movement by definition.
link |
And the basic takeaway that I was able to find was that
link |
if we are already warm from running or from weight training
link |
or from some other activity,
link |
that doing the static stretching practice
link |
at the end of that weight training or cardiovascular
link |
or other physical session would allow us to go immediately
link |
into the stretching session
link |
because we're already warm, so to speak.
link |
Otherwise, raising one's core body temperature by a bit
link |
by doing five to seven, maybe even 10 minutes
link |
of easy cardiovascular exercise or calisthenic movements
link |
provided you can do those without getting injured,
link |
seems to be an ideal way to warm up the body for stretching.
link |
We should be warm or warm up to stretch,
link |
although those warmups don't have to be extremely extensive.
link |
And then just by way of logic,
link |
doing the static stretching after resistance training
link |
or cardiovascular training seems to be most beneficial.
link |
In fact, and unfortunately we don't have time
link |
to go into this in too much detail today,
link |
I was able to find a number of papers that make the argument
link |
that static stretching prior to cardiovascular training,
link |
and maybe even prior to resistance training
link |
can limit our performance in running
link |
and resistance training.
link |
I realize that's a controversial area.
link |
You have those who say, no, it's immensely beneficial.
link |
You have those who say, no, it inhibits performance.
link |
And those that say, no, it's a matter of how exactly
link |
you perform that static stretching and which muscle groups
link |
and how you're doing this and how much time in between
link |
static stretching and performance.
link |
But to leave all that aside, doing static stretching
link |
after some other form of exercise,
link |
and if not after some form of exercise,
link |
after a brief warmup to raise your core body temperature,
link |
definitely seems like the right way to go.
link |
Now, for some of you out there,
link |
and I confess for me as well,
link |
doing something five days a week seems like a big commitment
link |
even if that commitment is one to only do three sets
link |
of 30 second static stretches.
link |
I say this because you've got the warmup.
link |
I generally like to bring a kind of a focus
link |
and dedication to a practice.
link |
And of course, because when doing these kinds of protocols,
link |
it's likely that you're not just stretching your hamstrings.
link |
So it's not just 90 seconds of work
link |
with a minute of rest in between,
link |
but very likely that we're also doing quadriceps stretching
link |
and also doing stretching for the shoulders
link |
and stretching for the back and the neck and so on.
link |
And so that entire session is going to take some time.
link |
And five days a week is a pretty serious commitment for most,
link |
especially for those of us that don't exercise
link |
or do athletics for a living, which I don't.
link |
So there is some evidence from the literature
link |
that one can get away with,
link |
or I don't even know that we should think about it
link |
as getting away with,
link |
but that one can do longer hold static stretches
link |
of up to say 60 seconds,
link |
but do fewer total sessions per week.
link |
So rather than three 30 second static holds,
link |
doing three 60 second static holds
link |
and doing those every other day.
link |
And there really hasn't been a systematic exploration
link |
of this, the article that I was referring to
link |
just a few moments ago,
link |
this analysis of the 23 articles
link |
was combined into this enormous set of tables
link |
and some really quite nice graphs
link |
that you're welcome to look at
link |
since we're going to provide a link to the study.
link |
There are a couple of key takeaways that I want to mention
link |
that are separate from this issue of
link |
how long to stretch and how often.
link |
First of all, they describe in their discussion
link |
that there were improvements in range of motion independent
link |
of whether or not people did static stretching,
link |
active stretching, passive stretching,
link |
ballistic stretching, or PNF stretching.
link |
So all of those forms of stretching
link |
will improve limb range of motion.
link |
This is essential to point out,
link |
and I want to emphasize this.
link |
Static stretching, however,
link |
gave the greatest degree of gains in limb range of motion.
link |
And on average, they saw a 20.9% increase,
link |
but some of the other increases they observed
link |
were also quite substantial.
link |
So ballistic stretching can also provide
link |
some pretty impressive limb range of motion improvements.
link |
However, they tended to be in the range of,
link |
here they point out 11.65% increase,
link |
or in the case of PNF, a 15% increase.
link |
So it appears that the greatest improvements
link |
in limb range of motion for your time spent
link |
and effort spent is going to be this minimum
link |
of five minutes per week to elicit a significant response,
link |
with five days being the minimum
link |
weekly recommended frequency
link |
to achieve significant range of motion improvements.
link |
I confess this was pretty surprising to me
link |
when I compare flexibility training to, say,
link |
resistance training for strength and hypertrophy.
link |
I've had the experience,
link |
and I know that other people have had the experience,
link |
and I think Dr. Andy Galpin would probably agree
link |
that provided one trains hard enough and appropriately,
link |
that you don't need to train resistance training
link |
five days a week in order to get significant improvements
link |
in strength and hypertrophy.
link |
Some people might need to,
link |
but you can get a lot of positive results
link |
in those variables with less frequent training,
link |
certainly with three or four days a week of training.
link |
And for cardiovascular training,
link |
I'm not aware of anyone having tested
link |
whether or not one very long run each week
link |
can actually increase cardiovascular fitness
link |
and you're not doing anything else,
link |
although I have to imagine you'd probably see
link |
some improvement compared to not doing anything.
link |
But most people are doing repeated training sessions
link |
of cardiovascular strength training.
link |
Not a lot of people are doing five days a week
link |
of strength training, at least that I'm aware of.
link |
Some people are, but most people I think are not.
link |
And some people are doing five or more days a week
link |
of cardiovascular training.
link |
I'm guessing that most people are not doing five days a week
link |
of dedicated static stretch range of motion
link |
directed training.
link |
But it does appear that that frequency about the week,
link |
getting those repeated sessions,
link |
even if they are short for an individual muscle group
link |
turns out to be important.
link |
And so that points to the, perhaps the reason
link |
why so few people are doing dedicated range of motion work.
link |
But it also reminds me that all of the studies
link |
that were described, at least in this review
link |
and some of the other ones that were not
link |
really show impressive changes in limb range of motion.
link |
I mean, 20 plus percent or even 15% with PNF.
link |
I mean, these are big changes that are going to benefit us.
link |
They're going to offset the age-related losses
link |
in flexibility for sure,
link |
if one is dedicated about these practices.
link |
And in many cases, they're going to increase limb range
link |
of motion in ways that are going to allow us
link |
better performance in certain physical endeavors,
link |
certainly better balance.
link |
Or we haven't really talked about balance and stability,
link |
but range of motion can impair balance and stability
link |
in some extreme circumstances.
link |
But by and large, limb range of motion,
link |
lack of tightness, improved posture,
link |
improved physical performance, excuse me,
link |
and things of that sort is something that I think
link |
we can all benefit from and that are key features
link |
We don't often think of them because we so prioritize
link |
cardiovascular health and the relationship
link |
between the heart and brain health and resistance training
link |
and musculoskeletal hypertrophy or strength, et cetera.
link |
But as I delved into this literature,
link |
it really highlighted for me the extent to which
link |
having really good limb range of motion,
link |
at least maintaining limb range of motion
link |
as we age from year to year,
link |
and maybe even improving limb range of motion
link |
can be immensely beneficial for reducing pain,
link |
for again, improving posture,
link |
improving our ability to perform, to walk, et cetera.
link |
And indeed there's a whole literature
link |
that relates our limb range of motion
link |
to things like pain management of things related
link |
to headache and so on and so forth.
link |
So limb range of motion is not just about becoming
link |
a contortionist or being able to complete the yoga class.
link |
It really is about maintaining the integrity and the health
link |
of the neuromuscular system, the connective tissue,
link |
and the neuromuscular connective network,
link |
because those are indeed working
link |
as an ecosystem and a network.
link |
I'd like to just briefly touch on PNF stretching
link |
Again, this is a vast landscape with many parameters
link |
and different practitioners,
link |
a lot of competing opinions out there to put it lightly.
link |
Nonetheless, I do want to emphasize
link |
that the PNF training leverages those spindle mechanisms
link |
and GTO mechanisms that we talked about earlier.
link |
But I realized that in describing
link |
the quadricep contraction hamstring stretch,
link |
little mini experiment that hopefully you did,
link |
that I didn't really highlight the role of the GTOs,
link |
the Golgi tendon organs that much.
link |
And I just would like to just briefly do that for a moment.
link |
The GTOs have multiple functions.
link |
In fact, I think even though GTOs are
link |
in every medical textbook, every physiology textbook,
link |
every first year neuroscientist learns about them
link |
when learning about the neuromuscular junctions
link |
and the mechanisms of interoception, et cetera,
link |
they are likely to have other functions as well.
link |
And one of the reasons why PNF stretching does work,
link |
whether or not you're doing that by using a strap
link |
to pull back a limb,
link |
or whether or not you're actively contracting
link |
your quadriceps to then release
link |
and emphasize stretch range of motion for your hamstrings
link |
and related muscle groups,
link |
is that activation of those GTOs,
link |
meaning putting loads and tension into that system,
link |
can inhibit the spindles
link |
in the opposite antagonistic muscle groups.
link |
And so one of the reasons why flexing,
link |
or I should say contracting your quadriceps
link |
really intensely for some period of time,
link |
allows your hamstrings to subsequently experience
link |
greater range of motion.
link |
And again, it's not just the hamstrings,
link |
but the related connective tissue
link |
and neural circuits, et cetera,
link |
is because yes, it's quote unquote relaxing
link |
the hamstrings and the spindle,
link |
but there's also a direct relationship
link |
between activation of the GTOs in the quadricep
link |
and release of the spindles
link |
in the hamstring and related muscles.
link |
This has a name, it's called autogenic inhibition.
link |
It's a fancy name for contraction of one muscle group,
link |
providing a relaxation of the other muscle group
link |
that's antagonistic to it.
link |
And it relates back to this idea of interleaving sets
link |
So if you think back to that example,
link |
now it should make sense as to why, for instance,
link |
if you do, let's say a set of bench presses
link |
or shoulder presses, and you,
link |
let's say you get 10 repetitions and you fail on the 11th,
link |
that muscle is very, very fatigued.
link |
If you were to rest some period of time
link |
and then go back and do another set,
link |
well, during the rest, that muscle group has been relaxing.
link |
It's obviously not contracting the same way it was
link |
during the resistance set.
link |
But by going and doing a pulling exercise
link |
that involves the antagonistic muscle group,
link |
so strongly contracting the back muscles through a pull,
link |
like a pull down or a chin up or a row type exercise,
link |
you're activating or near activating the GTO system
link |
in those pulling muscles in a way
link |
that provides autogenic inhibition for the pushing muscles.
link |
Now, again, the physios out there
link |
are probably either screaming or banging their heads
link |
against whatever sound system
link |
this happens to be arriving through
link |
to them saying, wait, but in many cases,
link |
the GTOs aren't activated enough
link |
to provide that autogenic inhibition.
link |
That's true, but even the sub-threshold activation
link |
of those intraspinal circuits,
link |
so the place where the GTO circuit
link |
and the spindle circuit interact,
link |
can provide an additional replenishment
link |
of say the pushing muscles
link |
while you're activating those pulling muscles.
link |
And this is at least one, not the only,
link |
but at least one mechanisms by which interleaving
link |
push and pull, push and pull
link |
for both strength and hypertrophy training,
link |
but also for range of motion stretching type training
link |
can allow you to achieve better results
link |
in a shorter period of time.
link |
And I raise this because I want to keep in mind
link |
the efficiency of any training program.
link |
We just a moment ago established that doing,
link |
for example, three sets of 30 seconds static holds
link |
can be very useful for the hamstrings
link |
with let's just say for sake of simplicity and practicality,
link |
a minute's rest in between.
link |
But during that minute's rest,
link |
you can stretch the opposite antagonistic muscle group,
link |
such as the quadriceps.
link |
Or if you want to use PNF training,
link |
you could do loading of the quadriceps in between.
link |
So there are a number of different ways
link |
in which you can start to interleave static stretching
link |
with PNF stretching.
link |
You can start to interleave even PNF type protocols
link |
with resistance training,
link |
although that gets a bit more complicated.
link |
You can really start to construct and build protocols
link |
that are ideal for you.
link |
What we will do is for an upcoming neural network newsletter.
link |
So for those of you that aren't familiar,
link |
the Huberman Lab Podcast
link |
has a so-called neural network newsletter.
link |
These are monthly newsletters
link |
where we put distilled points from the podcast
link |
and oftentimes protocols in a downloadable PDF form.
link |
You can access it by giving us your email.
link |
We don't share your email with anybody.
link |
If you want to see examples of these,
link |
you can go to HubermanLab.com
link |
and go to the menu and see newsletter.
link |
You don't have to sign up for anything
link |
to see examples of what these are like.
link |
I'll provide a couple of different protocols,
link |
one that is pure static stretching,
link |
one that involves PNF type stretching.
link |
And I'll also put down a protocol
link |
that involves the antagonistic interleaved muscle training
link |
of the sort that I've been describing
link |
a few times throughout this episode.
link |
And then you can try and apply those either separately
link |
or maybe combine them in some way
link |
that's useful for your goals.
link |
There are a couple of key elements
link |
that are essential for building a safe and effective
link |
range of motion increasing program
link |
that arrived to us both through the peer reviewed research
link |
and admittedly from people that have been involved
link |
in teaching and training range of motion
link |
for a very long period of time.
link |
Some of you may be familiar
link |
with the so-called Anderson Method.
link |
It's been around for a long time.
link |
I actually have never met Anderson.
link |
I don't, I should know this.
link |
I don't even know if he's still alive.
link |
I hope he's still alive.
link |
But in any event, there are a lot of different features
link |
to the Anderson and other protocols.
link |
But one of the aspects of the Anderson protocol
link |
that I think is highly relevant,
link |
in fact, I know is relevant to the peer reviewed research
link |
that we're going to talk about in a few moments,
link |
is this notion of pushing through pain
link |
and how active or how passive to be about static stretching.
link |
Now this is somewhat subjective, right?
link |
If you think about getting into a stretch,
link |
again, we'll just use the hamstrings for example.
link |
So you're either reaching for your toes
link |
while seated, or maybe you're using a strap
link |
and you're raising your foot overhead while lying down,
link |
or maybe you're doing a toe touch type exercise.
link |
How far should you reach?
link |
Where is the end range of motion?
link |
Should you bounce?
link |
Should you not bounce?
link |
We're going to talk a little bit more
link |
about that in a moment.
link |
But Anderson has an interesting idea and principle
link |
which is thread through a lot of his teachings
link |
that I think are very much in keeping
link |
with the study that I'm about to describe next.
link |
Where he emphasizes to yes,
link |
to stretch to the end of the range of motion,
link |
but not to focus so much on where that range of motion
link |
happens to be that day.
link |
So for instance, not thinking,
link |
oh, I can always touch my toes, for instance,
link |
and therefore that's the starting place
link |
for my flexibility training today.
link |
But rather to take the entirety of your system
link |
into account each day and understand that,
link |
okay, provided you're warmed up appropriately,
link |
that you're now going to stretch your hamstrings,
link |
for instance, and you're going to reach down for your toes,
link |
but that your range of motion might be adjusted that day
link |
by way of tension and stress,
link |
or by way of ambient temperature in the room.
link |
And to basically define the end range of motion
link |
as the place where you can feel the stretch
link |
in the relevant muscle groups.
link |
I think this is important because unlike resistance training
link |
or cardiovascular training,
link |
where we can measure distance traveled over time
link |
in the case of cardiovascular training,
link |
or how much weight is on the bar
link |
and count repetitions, et cetera,
link |
with range of motion training,
link |
of course, range of motion is the feature
link |
that we're interested in,
link |
but there is likely to be a lot of variation from day to day
link |
based on a number of different internal
link |
and external factors.
link |
And so the Anderson method is really about
link |
getting into static and other forms of stretching.
link |
I think today we've mainly been focusing
link |
on static stretching and holding the end range of motion,
link |
but really paying attention to the feel of the stretch
link |
and the muscles involved.
link |
And there are parallels in resistance
link |
in cardiovascular training too, I realize, right?
link |
In the case of trying to build hypertrophy,
link |
or I should say improve hypertrophy muscle size,
link |
oftentimes the best advice that one can give
link |
is to don't try to lift weights,
link |
but rather to challenge muscles.
link |
Now, of course, you need to provide adequate loads
link |
in order to get hypertrophy,
link |
but when you're training purely for strength,
link |
it's about moving weights.
link |
When you're training purely for hypertrophy
link |
or mainly for hypertrophy,
link |
it's really about challenging muscles
link |
using weights or other forms of resistance.
link |
And similarly, and in keeping with this Anderson method,
link |
when trying to build limb range of motion,
link |
doing static stretching at a place where it's difficult,
link |
but that you can experience the stretch of the muscle
link |
cognitively, consciously,
link |
being able to focus on the muscles and their stretch
link |
is at least as useful as is evaluating
link |
the current range of motion you're able to achieve.
link |
So what does this mean?
link |
This means feel the muscles as you stretch them,
link |
don't just go through the motions.
link |
And this means don't get so attached
link |
to being able to always achieve, for instance,
link |
a stretch of a given distance within a given session.
link |
You might actually find that by just finding the place
link |
where you can't get much further
link |
and holding the static stretch there,
link |
that on the second and third set
link |
that you happen to be doing that day,
link |
that your range of motion will be increased considerably.
link |
Maybe not, but very likely, yes, you will.
link |
And of course, evaluating range of motion over time
link |
is the key parameter,
link |
because that's the goal of all this type of work.
link |
Now, along these lines,
link |
there is this variable that we've mentioned a few times
link |
of passive versus active stretching.
link |
And there's this even more nebulous variable,
link |
this even more kind of subjective thing
link |
of how much effort to put into it.
link |
Should you push into the stretch?
link |
Do you even want to bounce a tiny bit?
link |
Would you want to reach into that end point
link |
and try and extend it within a given set and session?
link |
And for that reason, I was excited to find this paper
link |
entitled, A Comparison of Two Stretching Modalities
link |
on Lower Limb Range of Motion Measurements
link |
in Recreational Dancers.
link |
It happens to be done in recreational dancers.
link |
It's a six-week intervention program
link |
that compared low-intensity stretching,
link |
which they call micro stretching.
link |
They used a capital M,
link |
so I don't know if that means that it's proprietary,
link |
although I didn't see evidence of conflict of interest,
link |
but they call it micro stretching.
link |
But to be very clear,
link |
micro stretching in the case of this manuscript
link |
is low-intensity stretching.
link |
And they compared that with moderate intensity
link |
static stretching on an active and passive ranges of motion.
link |
Okay, so there are a lot of different variables are here,
link |
but I'll just highlight a few of the things
link |
that are really most relevant to us.
link |
And I'll give you the takeaway at the outset
link |
and then return to it at the end
link |
so that if I lose any of your attention
link |
in the next couple of minutes,
link |
at least you have that key takeaway.
link |
Basically, what they found was that
link |
a six-week training program
link |
using very low-intensity stretching
link |
had a greater positive effect on lower limb range of motion
link |
than did moderate intensity static stretching.
link |
I find that incredibly interesting.
link |
So very low intensity,
link |
and we'll define what that means in a moment.
link |
Here I'm quoting them.
link |
The most interesting aspect of the study
link |
was the greater increase in active range of motion
link |
compared to passive range of motion
link |
by the micro stretching group.
link |
So this relates to what we were just talking about
link |
a few moments ago as it relates to the Anderson method,
link |
which is that very low-intensity stretching,
link |
meaning effort that feels not painful,
link |
and in fact might even feel easy
link |
or at least not straining to exceed a given range of motion,
link |
turns out to not just be as effective,
link |
but more effective than moderate intensity stretching.
link |
So what is low-intensity static stretching?
link |
Well, they define this as the stretches were completed
link |
at an intensity of 30 to 40%,
link |
where 100% equals the point of pain, right?
link |
So 30 to 40% in these individuals,
link |
and again, I'm paraphrasing,
link |
induced a relaxed state within the individual
link |
and the specific muscle,
link |
and here they were holding these static stretches,
link |
I should mention, for one minute, not 30 seconds.
link |
Now, the control group was doing
link |
the exact same overall protocol,
link |
so daily stretching for six weeks, the same exercises,
link |
holding each set for 60 seconds,
link |
but we're using an intensity of stretch of 80%,
link |
where again, 100 represents the point of pain
link |
to the point where the person would want to stop stretching.
link |
I find these data incredibly interesting
link |
for I think what ought to be obvious reasons.
link |
If you're going to embark on a flexibility
link |
and stretching training program,
link |
you don't need to push to the point of pain.
link |
In fact, it seems that even just approaching
link |
the point of pain is going to be less effective
link |
than operating at this 30 to 40% of intensity
link |
prior to reaching that pain threshold,
link |
the pain threshold being 100%.
link |
Now, of course, this is pretty subjective,
link |
but I think all of us should be able to register
link |
within ourselves as to whether a given range of motion
link |
or extending a given range of motion
link |
brings us to that threshold of pain or near pain,
link |
and according to this study, at least, operating
link |
or performing stretching at an intensity that's quite low,
link |
that's very relaxing, turns out to be more beneficial
link |
in increasing range of motion than is doing exercises
link |
aimed at increasing range of motion at a higher intensity.
link |
Okay, so lower intensity stretching,
link |
I should say lower intensity static stretching
link |
appears to be the most beneficial way to approach stretching,
link |
and I think that's a relief probably to many of us
link |
because it also suggests that the injury risk
link |
is going to be lower than if one were pushing
link |
into the pain zone, so to speak.
link |
The authors offer a number of different explanations
link |
as to why this approach, this microstretching approach
link |
might be more effective.
link |
Here, I'm paraphrasing from their discussion
link |
where they mentioned that it could be hypothesized
link |
that they had improved reciprocal inhibition
link |
within the hamstring muscle group,
link |
so this gets right back to the sorts of neural mechanisms
link |
that we talked about before, that somehow,
link |
by doing this low intensity stretching,
link |
that they were able to access some of those spindle
link |
and GTO-type mechanisms that we were referring to earlier
link |
and the inhibition of hamstring and quadricep stretches.
link |
They also offer a number of different ideas
link |
about how this could shift the activation
link |
of the so-called sympathetic,
link |
remember the kind of stress division of our nervous system,
link |
and to reduce that relative to activation
link |
of the parasympathetic arm of the nervous system.
link |
I confess they have a couple of arguments
link |
around sympathetic, parasympathetic
link |
that are somewhat convoluted.
link |
I will just, in fairness to the neuroscience
link |
on those systems, I wouldn't suggest putting too much weight
link |
on their arguments about sympathetic and parasympathetic.
link |
To my mind, they didn't really hold much water,
link |
but here I'm not trying to be disparaging
link |
of the overall work, which I think is really quite sound,
link |
which is that low intensity so-called microstretching
link |
is going to be the most effective way
link |
to increase limb range of movement over time.
link |
I want to just briefly return to this idea
link |
of whether or not to do ballistic or static stretching
link |
before some sort of skill training or weight training
link |
or any kind of sport or even cardiovascular exercise
link |
Again, the data are really split out there.
link |
There are even folks who suggest
link |
that doing any kind of stretching prior to running
link |
is going to lower running efficiency.
link |
It's going to require essentially more work
link |
and more oxygen uptake at a given speed
link |
for a variety of reasons.
link |
And runners and that community argue about this endlessly.
link |
There are papers in both sides, in both directions.
link |
I'm sure I'll hear about some of this in the comments.
link |
I'm not really going to take a stance on this as a consequence
link |
because the data are all over the place.
link |
However, I think there's a general logic
link |
that we can apply in here.
link |
I'm borrowing from some conversations
link |
and some information put out there by Dr. Andy Galpin,
link |
who I think is, of course, both an expert
link |
and thinks about these things in a really sound
link |
and flexible way, no pun intended.
link |
There are instances, for example,
link |
where an individual might want to do some static stretching
link |
to increase limb range of motion
link |
prior to doing weight training,
link |
even if it's going to inhibit that person's ability
link |
to lift as much weight.
link |
Why would you want to do that?
link |
Well, for instance, if somebody has a tightness
link |
or a limitation in their neuromuscular connective
link |
tissue system someplace in their body and system
link |
that prevents them from using proper form
link |
that they can overcome by doing some static stretching,
link |
well, that would be a great idea, as Dr. Galpin points out.
link |
Or, for instance, if proper stability within the movement
link |
requires increasing limb range of motion in some way,
link |
well, then compromising the use of greater loads
link |
could be greatly offset by doing some static stretching
link |
to improve, say, hamstring flexibility
link |
or another muscle group flexibility.
link |
So we can't always think about just what's going to allow us
link |
or inhibit us from using the maximal amount of weight
link |
or from running as far as we want to run
link |
as fast as we want to run.
link |
There are instances where people are trying
link |
to overcome injuries, where they're trying to come back
link |
from a reparative surgery or something of that sort,
link |
coming back from a layoff,
link |
where some additional static stretching
link |
prior to cardiovascular weight training or skill training
link |
or sport of some kind is going to be useful
link |
because it's going to put us in a position
link |
of greater safety and confidence and performance overall,
link |
even if it's adjusting down our speed
link |
or the total amount of loads that we use.
link |
So it's you that needs to consider
link |
whether or not for you and within a given training session,
link |
you want to do static training,
link |
I should say static stretching range of motion training
link |
prior to or after that training session.
link |
And similarly, there are a lot of data points in the fact
link |
that doing some dynamic or even ballistic stretching
link |
prior to skill training or cardiovascular weight training
link |
can be beneficial in part to warm up
link |
the relevant neural circuits,
link |
joints and connective tissue and muscles,
link |
and as well to perhaps improve range of motion
link |
or ability to perform those movements more accurately
link |
with more stability and therefore with more confidence.
link |
And while Dr. Andy Galpin
link |
would never name any protocol after himself,
link |
he's far too humble to do that,
link |
I've named a couple of protocols after him,
link |
particularly the Galpin equation for hydration,
link |
because he was willing to stick his neck out there
link |
and put down some specific numbers that people could follow
link |
in order to ensure proper hydration during training,
link |
you can look up the Galpin equation elsewhere,
link |
you can just Google it or look elsewhere, you'll find it.
link |
And Dr. Galpin has also been very thoughtful and generous,
link |
and I think very accurate in offering
link |
a kind of a general organizational logic
link |
for how to think about the goals
link |
of a particular training session
link |
and thereby to decide whether or not
link |
you're going to do ballistic or static stretching
link |
and so on and so forth.
link |
So we can refer to this general approach
link |
as Galpinian, Galpinian, is that right?
link |
Galpinian logic, Galpinian logic.
link |
Thus far we've been talking about stretching
link |
for sake of increasing limb flexibility and range of motion,
link |
but there are other reasons perhaps
link |
to embark on a stretching protocol
link |
that include both our ability to relax
link |
and access deep relaxation quickly,
link |
as well as even to reduce inflammation
link |
and perhaps even combat certain forms of cancer.
link |
And if that sounds really far-fetched,
link |
I want to emphasize that the study
link |
I'm about to share with you in a moment
link |
was actually carried out by one of the directors
link |
of a division of the National Institutes of Health.
link |
And this was the work of Helene Langevin,
link |
who's a medical doctor, has done really important work
link |
on the mechanisms underlying things like acupuncture
link |
and has approached all that from a very mechanistic viewpoint
link |
so not looking just at the effects of acupuncture,
link |
but really trying to understand what sorts of cytokines,
link |
inflammatory molecules and pathways are activated,
link |
what sorts of neural mechanisms get engaged
link |
by things like acupuncture that impinges
link |
on the fascial tissues and so forth.
link |
And Dr. Langevin is currently a director
link |
of the National Institutes of Complementary Health
link |
and Medicine at the National Institutes of Health.
link |
So this is a major division supported by tax dollars
link |
that support systematic mechanistic exploration
link |
of things like respiration, meditation, yoga, acupuncture.
link |
So this is serious science applied to protocols
link |
and approaches that have been used for some period of time,
link |
but really aimed at trying to understand
link |
what would the best protocols be to evolve new protocols.
link |
So there's a really interesting study done in animal models,
link |
but I think it's a powerful enough result
link |
that I think we all should pay attention to it.
link |
The title of this paper, and again,
link |
the last author is Dr. Langevin herself,
link |
is stretching reduces tumor growth
link |
in a mouse breast cancer model.
link |
And yes, you can get mice to stretch.
link |
It turns out that if you gently lift up mice by their tail
link |
and they'll hold onto their cage,
link |
there's a way in which you can mechanically stretch them
link |
in a way that doesn't harm them.
link |
First, I should mention that Dr. Langevin and others
link |
have shown that just a brief whole body stretch
link |
of that sort induces an increase in activation
link |
of the parasympathetic arm of the autonomic nervous system.
link |
Again, not arm limb arm,
link |
but the aspect of the autonomic nervous system
link |
that creates a whole body, whole nervous system shift
link |
toward more relaxation.
link |
So yes, indeed, stretching induces relaxation
link |
at a systemic level, not just at a local level.
link |
And I think that's important,
link |
probably not surprising to those of you
link |
that use stretching regularly,
link |
but yes, it does indeed relax us.
link |
Yes, you can do this in mice and see that in mice as well.
link |
Here's what they did for this current study,
link |
or I should say this was a study published in 2018
link |
in Scientific Reports.
link |
They write, recent studies have shown
link |
that gentle daily stretching for 10 minutes
link |
can reduce local connective tissue inflammation and fibrosis.
link |
Now that's local tissue inflammation and fibrosis.
link |
As well, we now know as systemic inflammation
link |
and can induce relaxation systemically.
link |
In this case, they focused on mice, not humans.
link |
And mice were randomized
link |
to a stretch versus no stretch condition
link |
and were treated for 10 minutes,
link |
once a day for four weeks.
link |
So it's 10 minutes of this passive whole body stretching
link |
a day for four weeks.
link |
What's remarkable, I mean, just I have to say
link |
is just striking is that tumor volume in these mice,
link |
they were able to induce tumors in these mice
link |
and the tumor volume at the end point
link |
was 52% smaller in the stretch group
link |
compared to the no stretch group.
link |
This is a highly significant effect.
link |
And they point out in the absence of any other treatment.
link |
And they explored whether or not
link |
cytotoxic immune responses were activated
link |
and a number of other features.
link |
They weren't able to get too deeply
link |
into the underlying mechanisms,
link |
but this is pretty remarkable.
link |
Even three weeks into this stretching protocol,
link |
this daily stretching protocol for these mice,
link |
tumor volume was reduced.
link |
I mean, by, you know, it's almost halved.
link |
This is pretty incredible.
link |
So they have these measures of tumor volume
link |
and the only difference in the way these animals
link |
were treated and handled
link |
was the introduction of this daily stretch.
link |
I find this result to be, of course, limited
link |
to the extent that it's done in an animal model,
link |
not in humans, we have to point that out.
link |
But as they point out in their discussion,
link |
our results demonstrate a 52% reduction
link |
in mammary tumor growth over one month
link |
in mice undergoing stretching for 10 minutes a day
link |
without any other form of therapy.
link |
Do they think that stretching itself
link |
is changing the tumor size?
link |
In fact, they raised the possibility that stretching,
link |
because of its impact on the fascia,
link |
might even create micro environments
link |
that are more permissive for tumor growth
link |
in certain instances.
link |
So they're careful to emphasize
link |
what I also believe to be the case,
link |
which is that it's unlikely that the stretching itself
link |
was directly acting to reduce tumor size,
link |
but rather that there's this possible link
link |
between inflammation and immune exhaustion mechanisms
link |
that if you can periodically relax a nervous system,
link |
here through stretching,
link |
that it can affect certain pathways
link |
related to the immune system
link |
that would allow the immune system
link |
to combat tumor growth to a significant degree.
link |
So again, even though this is a study in mice,
link |
it argues that relaxation induced by stretching
link |
can have a powerful influence on mammary tumor growth.
link |
Again, a huge effect carried out
link |
by one of the premier labs and individuals
link |
who do this sort of work and think about this sort of thing.
link |
And of course, I want to point out,
link |
it wasn't just Dr. Langevin that did this study.
link |
There are a number of co-authors on the study.
link |
We'll provide a link to the co-authors,
link |
excuse me, we will provide a link to the study
link |
so that you can peruse it in more detail if you like.
link |
Now, as a related and somewhat final point,
link |
I'd like to return to this idea and this place,
link |
this real estate within our brain
link |
that we call the insular cortex, the insula.
link |
As you recall, way back at the beginning of this episode,
link |
we were talking about the von Economo neurons,
link |
that Constantine von Economo,
link |
the Austrian scientist discovered.
link |
And the fact that we are able to make
link |
and perform interpretations of our internal landscape, pain,
link |
our dedication to a practice, for instance,
link |
whether or not we are in pain because it's a practice
link |
that we are doing intentionally
link |
and want to improve ourselves,
link |
or whether or not it's pain that's arriving
link |
through some externally imposed demands or situations.
link |
Well, the insula is handling all that.
link |
And fortunately, there's a wonderful paper
link |
that was published, it was a few years ago now
link |
in the journal Cerebral Cortex, which is a fine journal.
link |
This is the year 2014, entitled Insular Cortex Mediates
link |
Increased Pain Tolerance in Yoga Practitioners.
link |
I'll tell you why I like this study.
link |
I'm personally not a practitioner of yoga.
link |
I've taken a few yoga classes over the years.
link |
I've done some of the hot yoga classes.
link |
Those rooms can get really, really warm, I confess.
link |
And I've done the kind of standard yoga every now and again.
link |
It's not something that I've kept up regularly.
link |
This study explored the effects on brain structure volume
link |
in yoga practitioners.
link |
And for those of you out there
link |
that are aficionados in yoga,
link |
they pulled subjects from having backgrounds in the,
link |
here I'm probably going to mispronounce
link |
these different things and forgive me,
link |
the vinyasa yogas, the ashtanga yogas,
link |
the yangar yogas, the sunanda yogas.
link |
Okay, so some people were new to these practices.
link |
Some were experienced.
link |
The important takeaways were that
link |
they took these yoga practitioners
link |
and they didn't explore their brain structure
link |
in the context of yoga itself.
link |
They looked at things like pain tolerance.
link |
So they used thermal stimulation,
link |
basically they put people into conditions
link |
where they gave them very hot or very cold stimuli
link |
and compared those yoga practitioners
link |
of varying levels of yoga experience
link |
to those that had no experience with yoga,
link |
so-called controls.
link |
And they found some really interesting things.
link |
I got a lot of data on this paper,
link |
but here's something I'd like to highlight.
link |
The pain tolerance of yoga practitioners
link |
was double or more to that of non-yoga practitioners,
link |
even for those that weren't doing the so-called hot yoga.
link |
They also found that pain tolerance was significantly greater
link |
both for heat pain and for cold pain.
link |
They also found significant increases in insular,
link |
again, the insula, this brain region, gray matter volume.
link |
Typically, when we talk about gray matter,
link |
we're talking about the so-called cell bodies,
link |
the location in neurons where the genome is housed
link |
and where all the housekeeping stuff is there.
link |
And then white matter volume tends to be the axons,
link |
the wires, because they're in sheaths
link |
with this stuff that appears white in MRIs
link |
and indeed is white under the microscope
link |
and indeed is white.
link |
It's actually lipid, which is myelin.
link |
So increased gray matter volume of the insula
link |
is a significant finding because what it suggests
link |
is that people that are doing yoga
link |
have an increased volume of these areas of the brain
link |
that are associated with interoceptive awareness
link |
and for being able to make judgments about pain
link |
and why one is experiencing pain,
link |
not just to lean away from pain,
link |
but to utilize or leverage or even overcome pain.
link |
So there are many studies of yoga and meditation out there,
link |
few that have as much mechanistic detail as this one.
link |
And in fact, there's a beautiful figure,
link |
figure three in this paper,
link |
that shows that the gray matter volume
link |
of this particular brain region scales
link |
in an almost linear way with the duration of yoga practice
link |
that somebody has been taking on in years.
link |
So people that had, they had a few subjects
link |
that have up to 15 or 16 years of yoga practice
link |
had much larger left insular gray matter volume,
link |
bigger brain areas associated with these abilities.
link |
And I find this interesting
link |
because there are a lot of activities out there
link |
that don't create these kinds of changes in brain volume,
link |
especially within the insula.
link |
So it appears that it's not just the performance
link |
of the yogic movements, but the overcoming
link |
or the kind of pushing into the end ranges of motion
link |
and to push through discomfort to some extent,
link |
of course, we want people doing that in a healthy safe way,
link |
but that's allows yoga practitioners
link |
to build up the structure and function of these brain areas
link |
that allow them to cope with pain better
link |
than other individuals and to cope with other kinds
link |
of interoceptive challenges, if you will,
link |
not just pain, but cold, not just pain,
link |
but discomfort of being in a particular position
link |
And again, we wouldn't want people placing themselves
link |
into a compromised position literally that would harm them,
link |
especially given that earlier we heard that micro stretching
link |
of the kind of non-painful sort, low intensity sort
link |
is actually going to be more effective
link |
for increasing end range of motion.
link |
But this study really emphasizes the extent
link |
to which practitioners of yoga don't just learn movements,
link |
they learn how to control their nervous system in ways
link |
that really reshapes their relationship to pain,
link |
to flexibility and to the kinds of things
link |
that the neuromuscular system was designed to do.
link |
And as a final point,
link |
there's a beautiful graph in this paper, beautiful,
link |
I think, because it explores some
link |
of the more subjective dimensions of yoga
link |
and insular function, which is a,
link |
here I'll read it out in the nerdy form,
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and then I'll explain what it means.
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This is a frequency histogram of categories
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of mental strategies used by yogis versus controls
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during the cold pain tolerance task.
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What they're describing here and showing is quantitatively
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how people are conceptualizing cold pain
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in order to get through it.
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And the different categories are,
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for instance, distraction, right?
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Some people just choose to distract themselves from pain
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or to attempt to, other people will try to ignore it.
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It's a lot like distraction, but nonetheless,
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to engage in a negative emotion,
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sort of like, I'm going to dig, I'm going to be in resistance
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Control subjects tended to use those approaches,
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whereas practitioners of yoga tended to use other sorts
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of subjective approaches like positive imagery
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to some extent, the ability to relax
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despite the extreme cold,
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the ability to quote unquote accept,
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like this is just happening despite the extreme cold,
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to observe, to third person themselves,
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and the greatest effect of course was to breathe,
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to focus on their respiration as a way to deal
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with this challenge, this cold challenge.
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Now, all of that is our subjective data,
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but I want to remind you that the practitioners of yoga
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are not just using entirely different mental strategies,
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but they are far more effective at dealing with pain.
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Their pain tolerance is much higher as evidenced
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by the other data in the previous graphs in the paper.
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So while this podcast episode is most certainly not
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about yoga per se, it's about flexibility and stretching.
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Flexibility and stretching are elements
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within yogic practices.
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And of course, yoga practices involve breathing
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and mental work and a lot of other things,
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balance, et cetera.
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It's a vast landscape as many of you know.
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But I think that if ever there was a manuscript
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that pointed to the utility of something like yoga
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for sake of tapping into a particular set of brain circuits
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and mechanisms that could wick out
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into multiple dimensions of life,
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so day-to-day life, stress, challenges in dealing
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with all sorts of external stressors, career related,
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family related, relationally, et cetera, excuse me,
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but as well for increasing range of motion,
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for increasing flexibility.
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So if ever there was a practice that one could embark on
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that would not only increase flexibility
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and limb range of motion,
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but would also allow one to cultivate
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some improved mental functioning
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as it relates to pain tolerance
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and other features of stress management
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that no doubt wick out into other areas of life,
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appears that yoga is a quite useful practice.
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And so for those of you that are interested
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in increasing limb range of motion
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and you're already a practitioner of yoga, great.
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I can imagine that someday there'll be another study
link |
like this one and you'll be in that 10 or 15
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to 16 year practitioner graph.
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You'll be that dot way out on the far end of the graph
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that shows that your insula is that much bigger
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than the rest of ours.
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And therefore your internal awareness and pain thresholds
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and stress management will be that much better.
link |
But of course, yoga isn't the only way
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to increase limb range of motion and flexibility.
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Up until now, we've described a number of different ways
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to do that and we've arrived at some general themes
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Again, those themes and protocols will be distilled
link |
into some specific and precise lists
link |
in our neural network newsletter,
link |
but we can revisit a couple of them now
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just in summary and synthesis.
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Static stretching appears to be at least among
link |
the more useful forms of stretching.
link |
So low or zero momentum stretching,
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typically at end range of motion.
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I love this concept of micro stretching,
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even though it's just a couple of studies
link |
that have addressed whether or not high intensity
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or low intensity static stretch holds are more beneficial.
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The idea and indeed the data that low intensity,
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so 30 to 40% of what one would consider painful
link |
appears to be more effective than 80% of that threshold.
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Find that incredibly interesting.
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And then there's this idea of frequency.
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It really does appear that getting at least five minutes
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per week total of stretching for a given muscle group
link |
is important for creating meaningful lasting changes
link |
in limb range of motion.
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And that is best achieved by five day a week
link |
or six day a week, or even seven day a week protocols.
link |
But those can be very short protocols,
link |
limited to say three sets of 30,
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maybe in 45 or 60 seconds of static hold.
link |
Although 30 seconds seems to be a key threshold there
link |
that can get you maximum benefit.
link |
There is no need to do full 60 second holds
link |
unless you're doing fewer total sessions per week.
link |
And of course, to always warm up
link |
or to arrive at the stretching session warm.
link |
And then of course, there are the other forms of stretching
link |
that we touched upon a bit, things like PNF.
link |
And we talked about why PNF works,
link |
things like the spindle and the Golgi tendon organ reflexes
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that are built into all of us
link |
that we arrive in this world with.
link |
And of course, the other forms of stretching
link |
that are known to be effective and important,
link |
such as dynamic and ballistic stretching.
link |
Again, stretching protocols that involve a lot of momentum
link |
in order to improve range of motion
link |
for performance of particular types of work
link |
that one is about to embark on.
link |
Typically that would be physical work,
link |
but a whole interesting and unexplored landscape
link |
is the extent to which changing limb range of motion
link |
and different types of body movement
link |
actually shape our cognitive abilities.
link |
And that will be the topic of a future episode
link |
If you're learning from and are enjoying this podcast,
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please subscribe to our YouTube channel.
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That's a terrific zero cost way to support us.
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In addition, please subscribe to our podcast
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If you have feedback such as comments
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Please also check out the sponsors mentioned
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That's the best way to support this podcast.
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Not so much on today's episode,
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but in many episodes of the Huberman Lab Podcast,
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we talk about supplements.
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While supplements aren't necessary for everybody,
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many people derive tremendous benefit from them
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for things like improving the transition time
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and depth of sleep, or for improving focus,
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including things like anxiety management.
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For that reason, the Huberman Lab Podcast
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First of all, Momentus supplements
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Second of all, they ship internationally
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We hope that will be useful to you.
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As well, we wanted to have a single location
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the most often discussed supplements
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here on the Huberman Lab Podcast.
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So while the full catalog of those supplements
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You can find them by going to livemomentus.com
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Again, that's livemomentus.com slash Huberman
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If you're not already following Huberman Lab
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At both places, I describe science
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and science related tools
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that relate to some of the themes covered here
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on the Huberman Lab Podcast,
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but oftentimes I'll do posts
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that include information and tools
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not detailed here on the Huberman Lab Podcast.
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We also have a newsletter.
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I've mentioned this a few times during today's episode.
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It is the neural network newsletter.
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You can access that newsletter completely zero of cost.
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By going to HubermanLab.com,
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So sign up for the neural network newsletter
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So thank you once again for joining me today
link |
for a discussion about the neural and neuromuscular
link |
and connective tissue and skeletal aspects
link |
of flexibility and stretching.
link |
And as always, thank you for your interest in science.