Becoming an Evidence Informed Yin Yoga Teacher or Student: A Guided Journey Part Three

In this third episode in our Becoming an Evidence Informed Yin Teacher or Student, I'll be reviewing some actual papers for you that are not directly about Yin Yoga but instead about an important component of our practice, stretching. 

In this third episode in our Becoming an Evidence Informed Yin Teacher or Student, I'll be reviewing some actual papers for you that are not directly about Yin Yoga but instead about an important component of our practice, stretching. 

I'll demystify the effects of stretching on muscle hypertrophy and performance. And address the common belief that pain is always a result of tightness. We'll shed some light on the connection between static stretching and heavy resistance training. All by reviewing a selection of studies, highlighting the role and benefits of stretch training in reducing muscle loss, stimulating muscle growth, and enhancing strength and performance.

But there's more to stretching than meets the eye. We'll explore how it can mitigate inflammation and aid in tendon repair. We'll discuss the challenge of measuring tension and strain, the impact of resistance training on tendon stretching, and the value of referencing research in yoga teaching. 

To keep the conversation going, join us on our Facebook group 'Movement for Healing'.

And don't forget to tune in next week as we dive into topics like nervous system regulation, mindfulness, and their role in pain care.

Become an evidence informed Yin teacher or student, enroll in my Yin Yoga Teacher Training Module I: https://yoga.mandyryle.com/yin-teacher-training-module-i/

Join the conversation in my FREE Facebook group, Movement for Healing https://www.facebook.com/groups/710104050217437/

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Transcript

Speaker 1: 0:00

Welcome to the Yin Yoga Podcast. I'm your host, mandy Ryle, and I am so excited for the third in our series Becoming an Evidence-Informed Yin Yoga Teacher or Student. As promised, today, I will be reviewing some interesting evidence for you so that you can start to see, number one, how you put what you have been learning actually into the process of reading and processing research. Number two, so you can see how research literacy directly impacts you as a teacher or a practitioner of Yin. And then, finally, so that you can increase your body of knowledge around something so essential to our practice that would be stretching. There is a pervasive myth in our practice that stretching is just for gaining range of motion, and I am going to present some evidence for you in this episode which will help you to see all of the wonderful things that happen as a result of stretching, and I really hope that you can bring this into your teaching or into your practice immediately. I'm going to let you know also that I am providing the full text links for every single piece of research that I will be discussing in this episode. However, my show notes do not allow enough room for me to put all of those full text links into the podcast players, so here's what I'll do. Instead, I'm going to invite you to please join my Facebook group. It's a private group called Movement for Healing. Once approved in that group, you will see each of the full text links for the articles, and you will also have an opportunity to ask any follow up questions that you might have or to add any comments that you would like to add. I will leave a link to the Movement for Healing Facebook group in the show notes, or you can just head right to Facebook and type it in. Thank you so much for your interest in research literacy.

Speaker 1: 2:26

Here is episode number three. So, as you know, this is the third episode in my series Becoming an Evidence-Informed Young Teacher or Student. Right here at the outset, I want to let you know that there will be one more episode in this series, where I'll be reviewing evidence related to the nervous system and cognitive benefits of the practice of Yen, and I'll especially like to highlight how Yen can contribute to a pain care process, because that is, after all, my personal specialty. Today, though, we're going to be looking at how stretching specifically influences tissues, and I chose the three studies that I'll be discussing in this episode because they illuminate some outcomes of practice, some consequences of stretching that I do not think are widely known or certainly understood by our industry, yen Yoga and Yoga in general. So I am very excited to tell you this information, because I think it's really going to broaden your horizon and your love and awe for what we are actually doing in our practice.

Speaker 1: 4:02

So before we dive in, though, I want to make sure that you understand that reading one or two or three studies, or even six studies, is not really enough to truly be an expert on a topic. I mean, think about it. There is a reason that research must be duplicated by multiple organizations and different scientists before it's actually considered conclusive, right? So when a new interesting conclusion comes up in a piece of research, the next step is for somebody else to try to duplicate those results. And for the same reason, it's important that we don't limit our knowledge to just one study, but that we instead have a broad range of research that we can draw from.

Speaker 1: 4:52

So a lot of times, we sort of use evidence as like a blunt instrument to confirm our bias. We essentially would like cherry pick some evidence so that we can back up what we're trying to say, the point we're trying to make. But there is a better way to use evidence. I think that a better strategy is to use evidence to contribute to your personal body of knowledge so that you can continue to develop your own skills. A big part of this is continually challenging your own biases and assumptions. If you find a study that happened 20 years ago and you're like this is great. This is everything that I've been saying. I highly recommend that you make sure that you look at more recent evidence as well, because often you will find that there is some contradiction, some development, as maybe methods or technologies have advanced.

Speaker 1: 6:01

Becoming a really truly wonderful evidence informed teacher will require quite a bit of humility, and in fact, I think that's probably true for any profession, not just yoga teachers and yen teachers specifically. So that is a little bit troublesome because if you're just starting out in your research literacy journey, you're going to have to start with one or two or three or six studies. Right, and that's okay. It just means that you're building up your body of knowledge over time and you will accumulate knowledge that can help you to serve your population of students better or to customize your personal practice to become even more effective. That can happen in one or two or three studies. So I say this also to let you know that the studies that I'm going to discuss here are just a fraction of the research that has helped me to form my own opinions and to develop specific teaching protocols or strategies. Okay, I am not setting the holy grail by these particular studies, okay. So before we get started looking specifically at the research, I wanted to kind of back up and bring this to more of a practical realm, because what I've noticed about training yoga teachers all these years is that we really do best when we know how this is going to be applied specifically to our practice or to our teaching.

Speaker 1: 7:40

So let me help you to conceptualize how you will apply your new research literacy that you've been building over these last few weeks. For the most part, your students won't really see a huge difference in your teaching, right? They won't understand that what they see is just the very tip of the iceberg and that your body of knowledge and your skill and your wisdom is like the rest of the iceberg that's under the ocean, right? Massive amounts of information that you have to bring to bear at any given moment in the teaching experience or in a learning experience, but hopefully your students will feel the difference in the results that they're getting. I know that we like to talk about non ambition and practice and indeed that is important when you're in a practice experience but we need to be realistic here. People come to yoga because they're looking for a result. That's the only reason anyone does anything right.

Speaker 1: 8:51

So, regardless of what that result is, my assumption is that you can probably find evidence to help you, to help your students to get to that result more efficiently, more quickly, more completely. To be evidence informed will influence your, your post choices, your sequencing. It's going to impact your theming and that's gonna be much more important in next week's episode. It's going to impact your hands on assisting and perhaps most importantly I believe, it's going to impact the language that you use, the words that you choose. So let's just start with that one the language. How is your language potentially going to change as a result of being evidence informed? I'm gonna go out on a limb here and say that the first thing is you might avoid results-based language that would indicate that a quote stretch end quote could permanently lengthen tissues. So we might not make claims like that anymore that Yin yoga makes you more flexible because the tissues are lengthening. You'll understand more about that as we go today. You might instead focus on other benefits of the poses and you will have the information to back that up. Another thing that might happen to your language is you might reduce your language around the danger or safety of poses. I would say that's probably the biggest difference that it's made in my teaching and if that has piqued your interest, that you might change your thinking or language around danger or safety of poses.

Speaker 1: 10:43

Make sure that you tune into the episode next week because that's gonna be the lion's share of what we're gonna talk about, because I think it's so, so important. So if you are not currently subscribed to the podcast, quickly, just scroll up, hit that subscribe. Some podcast apps also allow you to opt in to alerts. Make sure that you have opted into those because I don't want you to miss that. That one is incredibly important for you, for your students, for our profession. So how could being evidence informed potentially change your pose choices? Once evidence informed, I think that you will understand that more intensity to a stretch will not change the length of muscles, so you might start to avoid some of the more gnarly difficult, harrowing poses, understanding that results can happen with a much smaller level of intensity.

Speaker 1: 11:45

Here's another thing that might change your pose choices is if you understand that pain is not the result of tightness. Pain is not the result of tightness. I just literally obliterated a sacred cow just now. I know we're gonna be doing a lot of that in this episode. So once you understand that pain is not the result of tightness, you might start to avoid prescribing or teaching specific stretches for that purpose, and I know as a yoga teacher myself, as a trainer of teachers, people are asking us all the time for a pose to stretch X, y or Z because it hurts. So perhaps being evidence informed could help you to give more helpful, beneficial suggestions to your students and could potentially help you to be empowered to address the true driver of tightness and sensitivity, which is the nervous system. We're gonna talk more about that next week.

Speaker 1: 12:57

Being evidence informed, you will likely develop strategies for helping to your students to embrace their range of motion, and you will do this because you will understand that range of motion is largely a product of genetics and bone morphology and that no amount of stretching can change those. So perhaps being evidence informed will help you to support students in working, accepting, being content with the body that they have. So, as I said, I'm gonna be sticking today with research that specifically addresses how duration stretching impacts tissues. And let me give a little disclaimer here Research rarely gives us an ironclad conclusion. Most of the time, it raises more questions, right, it's sort of like, okay, we got this result, but now we don't really know why. Now we need to look at that. We have more questions than we had when we started. But what research does do is it moves us slowly, inexorably, over time toward more effective strategies. It gives us more what, how, when, and that can be incredibly useful to a yoga professional and, I believe, to someone who simply loves the practice of the end.

Speaker 1: 14:29

So the reason I chose this first study is because it lays a few sacred cows in the yin world. Now I don't wanna come in and just steal your lollipop, but as a teacher, my mission is I am committed to encouraging more accurate and therefore effective practice, and so I think it's really, really important that we get honest about what our practice is actually doing and what it is actually not doing. So here are some sacred cows that I think you're gonna be maybe considering or reconsidering as a result of hearing about this particular piece of research. Here's the first one Static stretching can make you weak as it overstretches your tissues, and overstretch tissues are weak. So that's the first thing I think we're going to be reconsidering as a result of this evidence.

Speaker 1: 15:28

Okay, that's number one. That's a big one. Number two stretching is best for flexibility when things are too tight and therefore too strong. Yes, okay, that's another one we're going to look at. And then, finally, the type of stretching we do in Yin can cause injury through over-stretching. That's a big one. That is a huge one. And it's not just for teachers. How many students do you hear from that? You know they felt like they needed to come to a class or have a teacher to help them, to quote do it right so they don't quote hurt themselves, right. So this is a very pervasive myth in our industry and while I can't like really just 100% nail it right in the center, I am definitely going to help you to reconsider some of these myths and how we might get to a little bit more truth.

Speaker 1: 16:39

So the first study, as I mentioned, that I want to discuss is all about stretching. Most studies, the vast majority of studies about static stretching are examining flexibility or range of motion. Okay, this meta-analysis is different. There's not many at all which are studying static stretching for reasons other than flexibility or range of motion. In fact, this meta-analysis of animal studies was conducted to determine whether stretching can generate adequate mechanical tension to induce muscle hypertrophy.

Speaker 1: 17:29

What is muscle hypertrophy, you might be asking me. So it is a very complicated thing, but let's just say for simplicity that it is muscle growth. There are many, many factors which may contribute to muscle hypertrophy. If I'm being honest, I'll have to tell you that there are still a lot of unanswered questions about what causes muscle growth. But in general, muscle hypertrophy is muscles getting bigger as a result of mechanical tension. So all those bodybuilders who are headed into the gym every single day are mainly trying to increase the size of their muscles and, as a consequence, also getting stronger. But their primary goal is hypertrophy, whereas, for example, a powerlifter, they just want to lift something really heavy one or two times. They're not interested in muscle hypertrophy, muscle growth. They're interested in strength. So the two are correlated, but they are not exactly the same thing.

Speaker 1: 18:42

So this study wanted to look at if you could use a stretching protocol to generate enough mechanical tension to induce muscle hypertrophy or growth. The reason this study really sticks out to me is because it bridges my two big passions, which are heavy resistance training and Yin yoga. It's like a marriage made in heaven. So here's why the researchers wanted to know if stretching can do the same thing as resistance training, because and I'm going to quote the study directly here muscular hypertrophy depends on metabolic exhaustion as well as mechanical load on the muscle. Chemical tension seems to be the crucial factor to stimulate protein synthesis. Can I break that down for you? So basically, whether a muscle is stretching due to moving a heavy weight through a full range of motion or it's due to a stretch of sufficient intensity and duration, the body will have a similar adaptive response. That's kind of their hypothesis.

Speaker 1: 20:01

So in this meta-analysis they were looking for data specifically on muscle cross-sectional area. So in yoga we're always concerned about the length of muscle. When we're looking at studies looking at hypertrophy, they're looking at the width of the muscle, that is, the cross-sectional area. They were also looking at fiber cross-sectional area, so those would be the individual feshkles and in some limited studies they also looked at fiber number and length. We will not be considering each of these separately, as that's going to be way too in the weeds for this discussion. We're just going to think of all of these as hypertrophy.

Speaker 1: 20:50

So now that I've broken that down, here is the official hypothesis of this meta-analysis, which I took directly from the introduction Stretch training performed with sufficient intensity leads to high mechanical load that can trigger muscular hypertrophy as a long-term training effect. That's what they were testing for. This study pulled data from 16 studies. Those were only 16 of the many, many studies that they pulled actually meet the criteria for having collected the data that we just talked about using a duration stretch protocol. And the 16 studies all used animals as subjects, mostly mice and chickens.

Speaker 1: 21:42

So you might be wondering how useful, mandy, is this information, even to me, if they're looking at research on animals? We'll kind of touch on that in a second, but I want to let you know first of all that there are not many studies that are looking specifically at hypertrophy as a result of duration stretching on humans. There are very few. I think there's less than five or six that's not to say right and there are some which we're actually going to discuss, I promise, the other reason that they used animals in this protocol is because many of the interventions they use, the ways that they stretched the muscles, would not be appropriate or ethical to perform on humans, so that's why we use animals. I'm not going to weigh in on the ethics of using animals. I have to say I'm pretty uncomfortable with it as well, but also the world needs data, so it's a tricky subject.

Speaker 1: 22:50

Okay, so now that I've told you the hypothesis and the general study design, what were the results of this analysis? This is the question we all want answered. I want the results. So here they are. The findings show an almost continuous positive effect of long term stretching on hypertrophy, which means that in nearly every included study, there was only one on a single test subject, by the way which did not have a positive result, and positive means it did what they expected.

Speaker 1: 23:34

So what that means is that this duration stretching on these animals resulted in bigger muscles. In some cases, the muscles actually got stronger and in some cases, the stretch training even improved muscle performance. Muscle performance generally refers to maximum strength, so that's basically the maximum amount of weight that you can lift once, and speed strength, which is how quickly can you lift a heavy weight. So that improved as well as a result, my friends, of stretching. So already I hope you see where I'm going. When it comes to our sacred cows, right, they're just dropping like flies. Stretching improved strength and, in some cases, performance. However, most of the studies showed an increase in the amount of time it took a muscle to contract after stretch training. So, in other words, performance was decreased in all but a very limited amount of data. So I think what we can say there is that it is thus far inconclusive as to whether static stretching can improve muscle performance, but it appears to be able to improve strength, okay.

Speaker 1: 25:02

So a question you might be having is that obviously, humans and animals are different. You are correct. For example, the protein synthesis rate that was one of the things that they were testing for. Protein synthesis is required for muscle growth. We have to increase the size of proteins, the amount of proteins. It's a little bit unclear to this day what exactly is happening, but protein synthesis is important and we do know that humans experience a slower protein synthesis rate than chickens or mice. Chickens and mice are pretty quick within a few days, humans a couple of weeks. However, we still have muscle protein synthesis Okay, and there are enough similarities to conclude that stretch training could be beneficial.

Speaker 1: 25:56

These were the conclusions of the study. Stretch training could be beneficial for reducing muscle loss or stimulating muscle gain in people who can't do strength training. There is, my dear listener, some data about stretch training for humans which I would like to read somewhat directly from the paper. There's not that much data, so it won't take me long. Okay, so initial human studies show that long-term stretching interventions for several weeks can induce hypertrophic effects and or increase maximum strength.

Speaker 1: 26:47

For example, a study, simpson et al were able to achieve an average increase of 5.6% in muscle cross-sectional area through a stretching intervention with a duration of 3 minutes, 3 days per week for 6 weeks. This, I would say, is probably the most relevant study to what we do in Yin, because they were stretching 3 days a week for 3 minutes, which is a Yin hold right For 6 weeks. Now I don't want you to think that they are just doing a bunch of different stretches for 3 minutes. They are looking specifically at a target muscle. So a lot of times they're going to be doing the calf muscles, for example, but maybe you could do your hamstrings right, so any muscle that you can stretch in a very consistent way would be applicable to the research, I would think. So what that looks like is you or your student is going to be stretching 3 times a week. You're going to stretch those hamstrings for 3 minutes and you're going to do that for 6 weeks and not only was there an increase in strength, but it was also an increase in the cross-sectional area, basically the mass of the muscle. Okay, so the others have less applicability to our practice, but I think that they are helpful just for our body of knowledge.

Speaker 1: 28:24

So in Panini at all, they found an increase in muscle cross-sectional area of 23%, plus or minus 14% after a 12-week stretching intervention, with stretching durations up to 15 minutes per training session. So what you may have noticed there is that the results were significantly higher, but also the duration of the stretch was 15 minutes per training session. And if you're like me, by the way, I have not yet, but if you're like me, you're like holy sheesh. I got to look at that research, I got to look up Panini at all and I have to see what were the other parameters, what were the other methods of this 12-week stretching intervention, and I want to let you know that I am going to provide links to each of the studies that I mentioned in this podcast so that you can do just that. There is a citation for every single piece of research in this study. That was included.

Speaker 1: 29:33

Okay, in Nelson et al, they demonstrated a 29% increase in maximal strength after stretching the calf muscles for 30 seconds four times three days a week for 10 weeks. So this again pretty applicable. And the increase was phenomenal 29%. I mean guys, any gym bro would love a 29% increase in a strength in any muscle group in just 10 weeks. Right, and it doesn't require lifting heavy weight or doing calf raises, which are also really fun, but it's just stretching.

Speaker 1: 30:24

And then here's another one which is very, very interesting and compelling. In Coconin et al, they achieve significant improvements in various performance tests, such as a one rep max, knee extension and knee flexion. Let me break that down for you. Knee extension will be working your quadriceps, so how much could your quadriceps lift to extend your knee one time? Knee flexion will be working with your hamstrings, so how much could you, how much load could you withstand, to basically bend your knee? That's the knee flexion test. So those both improved. The standing long jump and high jump improved. So those are looking more at performance and elasticity.

Speaker 1: 31:10

And the protocol was static stretching for 40 minutes per session, three days a week for 10 weeks. So stretching a specific muscle in this case it would be the calves for actually that's not true. It is not mentioned. We're going to have to look up that citation, guys and check it out. That coconut at all, 40 minutes per session, three days a week for 10 weeks this is excessive. This is not going to show up in a neighborhood yin class, but it's really interesting to know that you can improve your strength significantly, your one rep max significantly, just through stretching and some pretty serious stretching.

Speaker 1: 31:55

So what this does right away is I hope it shows us that stretching does not make you weak, even like really extreme stretching. So we'll just take that in for a second, and you might be thinking some of these timings are really excessive and I want you to know that yes, they are. The other thing that was pretty extreme was the intensity, so that refers to how hard the muscle is being stretched. Like I said, I have not looked up these citations. I just needed to keep myself from going too far down the rabbit hole for the purposes of this podcast and actually getting it out to you on Wednesday at 9 am. But if you look at the data from the animals, they were stretching the muscle that they had chosen from the animal, anywhere from 12% to up to 30% of body weight, which is very, very, very extreme. But again, I think what this shows us is that over stretching is highly unlikely to cause excessive weakness. So we can eliminate this myth, perhaps that stretching makes you weak. That's the first one. Here's another myth that might still be true, but it's not a slam dunk.

Speaker 1: 33:34

Stretching negatively impacts performance. We don't have firm conclusions on this yet, but another study that was simply cited in this meta-analysis used a daily duration stretching protocol for the plantar flexors. So those are the muscles which help you point your foot, and this research showed significant increases in maximal strength, muscle thickness and flexibility. So here we see at least with the plantar flexors, flexibility and strength can be improved simultaneously. I think that the current narrative, not just in the yoga world but also in the strength world, is that you can only have one at the expense of the other. But what this showed was stretching could improve strength and flexibility, and I think this goes in hand and hand with other research that I have read which shows that resistance training outperforms static stretching in improving range of motion. So, in other words, lifting weights can help you to improve your range of motion about as well as static stretching. However, research also shows that resistance training plus static stretching is the very best for improving range of motion. So I hope that your head is kind of exploding right now With all of this great information, which can hopefully help you as a practitioner, and definitely you if you're a teacher, to feel more comfortable and safe about recommending yin yoga or teaching yin yoga, knowing that it is very unlikely that your students will be overstretched.

Speaker 1: 35:46

So another thing I want to point out about this data is that some of the studies stretch the animals muscles continuously for days or weeks and those studies demonstrated the highest effect size, the best results. So, for obvious reasons, that's not going to be something that we're going to do in yin and this probably never even going to be studied on humans. It's probably not applicable even in a clinical setting, although I would imagine if someone is immobilized somehow anyway, it could be helpful. But what I wanted to show you again is that it is not dangerous to stretch my hope in reviewing this study for you is that we can start to change the conversation about weak flexibility and strong tightness, and I think that this is also very compelling information about our industry fears about overstretching.

Speaker 1: 36:39

Do some people experience pain as a result of their practice? Yes, I'm not here to gaslight anyone who has experienced pain as a result of stretching their yin practice, their vinyasa practice. Pain happens. The question is is it due to over stretching? The evidence here and elsewhere says no. I will touch more on this in just a little bit.

Speaker 1: 37:04

So let's talk about another study which talks about stretching and other things outside of the realm of flexibility. This was a study on rats. The scientists injected the back of the rat with an inflammatory substance called caragenin, and if you are remembering this word, caragenin, it's probably because you read it on the back of your oat milk container, your almond milk, your coconut milk container. It was used widely in all of those non-dairy milks as a binder. I think that it has sort of been outlawed, but I'm still seeing it, so maybe it's still allowed in certain percentages in these products.

Speaker 1: 37:52

Ever since I read this study several years ago, though, I have been avoiding caragenin like the plague, because it was literally used to cause pain and inflammation in these rats, and, yes, were they getting a lot more caragenin than you do in your oat milk? Absolutely Still, I don't think I want any part of it. So, after they injected these rats with this caragenin substance and they witnessed that there was pain and inflammation, they then proceeded to stretch the back of the rat and there's a diagram showing you how. It stretched the rat for 10 minutes twice daily, and what they found was that protocol reduced inflammation and improved pain within two weeks of the caragenin injection. A follow-up study to that study showed that the reduction of inflammation was due to the reduction of pro-inflammatory immune cells. In the actual research, it breaks down the different immune cells and all of the different information. I don't think we need to go that into the weeds for this. Basically, what it's saying, though, is that there was a reduction of inflammation, which they then concluded was a reduction in pro-inflammatory immune cells.

Speaker 1: 39:08

So, as you know, I mostly work with people who are managing a pain issue, so inflammation is a major concern, and probably should be a major concern, by the way, for every adult on the planet, since inflammation is a direct cause of pretty much every chronic illness that we have. So even though the data shows that static stretching resolves inflammation in rats injected with caragenin, that may feel like wow, mandy, that is really a wide bridge to cover here. To me, reading research like this is kind of a what is the harm in recommending static stretches to my clients, like, yes, we don't have this data on humans yet, but static stretching feels really good, it is almost universally well-tolerated, there is no copay, there are no side effects, or very few side effects, right. So if it's possible that this data could transfer to humans, why shouldn't I just kind of try it out? And so sometimes we use research, not because it's super conclusive, but because there's really no harm in trying with something like this and so many of the things we do in this profession or in this practice.

Speaker 1: 40:29

I want to talk about just one more study. This one will be brief. This study showed that stretching can help tendon injuries to heal. Tendon injuries to heal. Now I remember learning in my teacher training years ago my 200 hour that tendons have no independent blood supply and therefore they never really heal once they're stretched. They're stretched for life, right Like the credit card analogy in the the Yin site. So the complete guide to Yin yoga by Bernie Clark. In fact I probably taught this myself in my 200 hour trainings that I have taught. But this is a really revelatory piece of evidence because it showed, it concluded, that dynamic uniaxial stretching stimulates the biomechanical conditions of natural tendons by inducing tenogenic differentiation, alignment of cells and extracellular matrix, and promotes tendon repair and regeneration, promotes tendon repair. So we're all concerned about overstretching, but it turns out static stretching could actually promote tendon repair and regeneration and all of those other wonderful things too, inducing tenogenic differentiation and lining cells, ecm. So I will give you the link to this study, I promise, so you can look at it yourself. But I will say that what they concluded this was a meta analysis, by the way. So they looked at a bunch of different studies that were looking at natural tendons and also lab generated tendons.

Speaker 1: 42:14

The frequency of an effective protocol and bioreactors is not usually higher than 1 Hertz, which is a unit of frequency equivalent to one event or cycle per second. Okay, one Hertz and between 1 and 12% strain. So they strained the tendon between 1 and 12%. That was the. You know, depending on the study, some did 1%, some did 12, some did 8, some 10, 6, some did 3. But all of them were somewhat effective in wound healing.

Speaker 1: 42:52

So you might be like, okay, how does that break down in my body? What is? 1%, 12% feel like strain for a tendon and it is extremely difficult to conceptualize, to measure, and the fact is you're never really going to know. Have you strained your hamstring, the proximal hamstrings tendon? 6%, for example, in your caterpillar pose? Like that's impossible, because stretching a tendon is really challenging when you're quote stretching, since the myofascia, that's the muscle with its fascia, takes up most of the stress. It's pretty stretchy and then when you're stopped stretching it, it's elastic and it comes back to shape. So the myofascia is going to take up the primary, the largest amount of the tension, and then there will be other structures that can kind of take up some of the tension. And only when the tension reaches a sufficient level of intensity will you actually be stretching your tendon, which is why the best way to stretch a tendon is actually resistance training.

Speaker 1: 44:01

So I want to mention something about this. So, working with people who live with chronic pain, who are already a little plugged into the yoga world, I encounter many, many clients who have pain which they attribute to over stretching, specifically a tendon attachment sites. The ones that pop up the most in yoga are the proximal hamstrings tendons, so that's where your hamstrings attach to your pelvis, at the sitting bones, the ischial tuberosities, and a lot of your yogis. Out there are like oh, I have that pain. Right, it's like an achy. Sometimes it can be very sharp, almost a sick feeling. It's like you just think I got to stretch it, I have to stretch it. And then another one is the lateral hip. That would be where the gluteal tendon attaches, just below the greater trochanter. Those are the most common for yogis and even though and, by the way, the feeling on that one is the same just achy, sometimes sharp, certain movements really really bad, wakes you up at night, very painful when sitting, like those are all the kind of things that happen and these are known.

Speaker 1: 45:23

Potentially. Obviously I can't diagnose you either in person or over the podcast, but these are symptoms which are typically attributed to a tendonopathy and even though stretching can reduce inflammation and it can potentially help with tendon regeneration and repair, stretching is the very last thing you should do for these injuries. So I didn't feel like it would be responsible for me to give you all this great information about stretching, and if you potentially have an issue in one of these areas and you would like help with it, you can certainly reach out to me. I do online coaching. I've helped many, many people with this problem or you can find someone else who is qualified to help you with a tendonopathy. I have found that tendonopathy protocol is really, really helpful, even for people who have never had a diagnosis of tendonopathy.

Speaker 1: 46:24

So in this episode, you learned that stretching is so much more complicated than you have been led to believe and potentially so much more beneficial than for just range of motion and flexibility. I hope you've learned that it is not as simple as stretch it. To lengthen it right Stretching could increase the cross sectional area of your muscle, and I hope that you've also learned that many of our concerns about overstretching and injury are unfounded when we go down the evidence rabbit hole. You have also learned that di duration and dynamic stretching can potentially potentially help to resolve inflammation and to speed up tissue healing. So the question is how will you use this information in your teaching or practice? At this moment, it might be helpful to just reflect a little bit on that.

Speaker 1: 47:26

So here's a question for you Will you lean into the benefits of stretching other than flexibility? Will you change your language around the postures, around stretching, around the benefits of stretching? If I'm honest, I would say that I would actually really love to hear your responses to these questions. I would love to hear if you have any follow up questions for me or if you have read research that you think would be an interesting adjunct to what we've discussed here on the podcast today. So to do that, I would recommend that you join my private Facebook group. It's called Movement for Healing. It is a great place just to ask me questions and pick my brain.

Speaker 1: 48:26

I'm going to leave a link in the show notes, and here's the other reason why you should definitely consider joining my Facebook group.

Speaker 1: 48:36

I am going to put all of the links to the research which I have discussed in the Movement for Healing Facebook group. I only get so many characters in my show notes, so there's no way I could include this in the show notes. So type in to Facebook, movement for Healing, or click the link in the show notes, and that will take you right there. You will have to request to be allowed into the group and then, once I approve you, you'll see all of the articles right there. All you have to do is click. All of these are open access articles, so obviously I've only scratched the surface here on how evidence can enhance your teaching and your personal practice. Next week, I am very, very excited to tell you about research that is related to other important aspects of our practice and many of us would say the more important aspects of our practice. That would be nervous system regulation, mindfulness, attention, and I am going to apply these specifically to my great passion, which is pain care. Thank you so much for listening and for your interest in research literacy.