Static Stretching: is this a good thing?

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Bernie
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Joined: Sat Sep 23, 2006 2:25 am
Location: Vancouver

Static Stretching: is this a good thing?

Post by Bernie »

Recently I have received a few similar questions regarding static stretching, questioning the validity of this form of exercise. Obviously, Yin Yoga employs static stretches a lot, thus the concern raised by students and teachers who have read that this form of exercise is dangerous and/or unhealthy. Here is one of the questions, and the discourse that flowed via email afterwards. (My contributions are in black, the other person’s in blue.) For those interested in this topic, feel free to join the discussion.

Cheers, Bernie

I have a question regarding an approach in Yin yoga. The latest research clearly demonstrates that holding the stretch for longer then15 sec is not advisable, unless you are young and pursuing ballet, dance, or martial art. How does Yin yoga play into this new science? I like holding stretches myself, but my background in martial art and gymnastics is not typical for average student. With respect, namaste, …[ps …] my education and former profession - M.D.


I would be interested in seeing what you call “the latest research.” Since you are an MD, let’s get technical. What we “hold” is not the stretch but the stress. (In Yin Yoga we don’t actually try to stretch the ligaments but we do try to stress them.) Maintaining a stress for less than 15 seconds when we are targeting the connective tissues would not give the stress a chance to get into the cells. One example should suffice: orthodontic braces. This is just one example of a yin stress on connective tissues (yin being defined as long held, static tension.) Imagine if you had to take off the braces and put them back on every 15 seconds? Clearly that is not practical nor necessary: with the long held static stress in place for months or years, the jaw bone remodels. Other examples of traction teach us the same thing: long held stresses of the ligaments allow the stress to reach the fibroblast and through mechanotransduction, stimulate the fibroblasts to do their thing (create more collagen, etc.) Yin Yoga is a form of traction, which is best done over long, static periods. For the joint we apply a distraction, also for long periods, which can stimulate the fibroblasts, the chondrocytes and osteocytes to get busy. [See chapter 6 of my book: The Complete Guide to Yin Yoga.]

Regardless of the theory, the practice shows it efficacy - long held stress does result in increased range of motion and rejuvenated joints. You say that you have witnessed this yourself. Seeing is believing. Its benefits are not restricted to the young, active or flexible. I have had many elderly students resolve many long standing issues through their Yin Yoga practice.


Hi Bernie, I have read your book. It has very good insights and organized logic. You do know how to drive your point persuasively. I cannot argue with the theory of braces and other immobilization techniques, used for treatment of different misaligned or broken bones, as well as there is no argument for the static stretch to benefit serious contraction spasm, as in cerebral palsy, after strokes, etc. Of course 10 sec stretch is difficult to call the stretch, but it seems 60 sec is the maximum recommended and usually for older patients. However I strongly agree that the maximum benefits for longevity and functional mobility comes from movement, not static tension. Gerald M. Silverman, DC in his book, Your Miraculous back, 2006, p.120, wrote, “The drawback to yoga are that it lacks specificity in targeting precise spasms and that the poses do not produce dynamic motion that helps lay down organized tissue patterns.” Following are some studies on the subject from quick search.
Namaste…

Effects of static stretching in warm-up on repeated sprint performance. By J Strength Cond Res. 2009; 23(7):2155-62 (ISSN: 1533-4287)
Sim AY; Dawson BT; Guelfi KJ; Wallman KE; Young WB School of Sport Science, Exercise and Health, University of Western Australia, Perth, Australia. Overall, these results suggest that 20-m repeated sprint ability may be compromised when static stretching is conducted after dynamic activities and immediately prior to performance (D-S).

A review of the acute effects of static and dynamic stretching on performance. By Eur J Appl Physiol. 2011; 111(11):2633-51 (ISSN: 1439-6327) Behm DG; Chaouachi A School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NF, A1C 5S7, Canada.
...Sports that necessitate a high degree of static flexibility should use short duration static stretches with lower intensity stretches in a trained population to minimize the possibilities of impairments. ..

American College of Sports Medicine position stand. Quantity and quality of exercise for developing and maintaining cardiorespiratory, musculoskeletal, and neuromotor fitness in apparently healthy adults: guidance for prescribing exercise.


The examples you sent were all related to the yang tissues of the body: the “muscles and tendons”. In the yang world, when we are targeting muscular restrictions to our natural range of motion, I would concur with shorter holds of the poses. Yang tissues do seem to do better with yang stress: brief, rhythmic and repetitive. However, muscles are not the whole story when we seek optimal health nor maximum performance.

A study by Johns and Wright showed that only about 41% of our “stiffness” is attributable to the muscles; the joint capsule contributed 47%. Targeting the muscles is great, but not the whole story. The point of yin yoga is to target the yin tissues, the other stuff that keeps us stiff. The safest and surest way to work those tissues is in a yin manner: long held static stresses. Your examples are not directed at those tissues. Of course, health does not require simply greater or nominal range of motion and that is only one reason why we might do yoga. Studies of disk degeneration, herniated disks, etc shows that McKenzie Therapy is very effective: this is a long held, static backbend done by having the patient simply lie on her stomach for several minutes at a time. [See this meta study that showed this to be more effective than any other interventions for some kinds of discogenic pain.]

Again, I would invite you to be empirical as well in your investigation. Unfortunately there are not a lot of controlled, double blind experiments done in this field but personal experience cannot be discarded. It does work for many people.


I agree to disagree. Your references to yin tissues, which require prolong stretch, is true for those who want extreme ROM and already possess great strength (gymnasts, circus, martial art). I would insist that the stretch of ligaments and joint capsule does more harm than good. The asanas, you recommend in your book, stretch the muscles as well. You cannot apply the tension to the bone or joint capsule without tugging onto the muscle, which fascia, tendons, and ligaments are blending into the capsule first. With age we lose stability due to the loss of muscle strength, if you add to it extra ROM the result is futile. The empirical "feels good" is not good enough. As you know there is always a possibility of placebo effect. (No trial has yet compared McKenzie to placebo or no treatment.)

You might know that the prolong hold stretches (traction) for treatment of disc herniation were proven to be no better than placebo or no treatment and are not used anymore as treatment modality with exception of numerous spinal stretching devices for sale. ([See this study…]The reviewers felt there was inconclusive evidence overall for either form of traction, based upon the methodologic quality of the numerous studies reviewed

I leave this discussion open. Obviously you have your strong opinion, which I respect. There is no argument that pathologically damaged yin tissue does need prolonged stretch, as I mentioned in the case of cerebral palsy, contraction after immobilization in case of broken bones, etc. I would not include aging or prolong sitting at the desk into this category. Also, the asanas will stretch the muscles to bigger degree than the ligament. It is impossible to isolate the joint capsule from the layers of muscles on top of it. Those surrounding muscles will loose their strength, they loose their "springs".



It is great to have a healthy disagreement to flush out and flesh out what is really important. If you are willing to stay engaged a little while longer (and I do appreciate having someone who is conversant with the medical/technical implications engaging in such a dialogue) I would make a few more points:

1) The placebo effect: so many people decry the placebo effect as if it was a bad thing! 97% of UK doctors have given placebos to their patients. One study showed that even when the patient is told the medicine is just a placebo, it can still work! Placebos, or things that work as well as placebos, work! Just because it is a placebo doesn’t mean it shouldn’t be used – if it helps a student/patient, why not use it? Yoga is a very cheap placebo (if that is what it is) and has a lot fewer side effects than many drugs. Just because some physical intervention (like McKenzie Therapy - MT) may work no better than a placebo doesn’t mean it is not valuable. But the point about MT was not that it was only as good as a placebo, but simply that it hadn’t been tested against a placebo: it has been tested against other interventions and was found to be as least as good as those treatments. I don’t know if those other treatments had gone through double-blind, controlled tests but if they have, then by the commutative principle we could imply MT has as well.

2) There are more domains of benefit for yoga in general and Yin Yoga in particular than just the physical: there have been studies into the energetic benefits of yoga (yogic breathing triggering the parasympathetic nervous system, enhancing GABA production, etc.) and the psychological benefits (mindfulness based stress reduction), not to mention the difficult to quantify spiritual benefits. Yoga is calming, soothing, relaxing, etc. This has its own physical and psychological benefits as well.

3) This does not mean that I am giving up on the physical benefits, but just to show that there are many reasons and intentions behind yoga practice. But, back to the physical discussion – your point about short stretches is, I would agree, appropriate in a “warm up process” before some other physical activity. I often tell my students who play hockey or tennis “Don’t do Yin Yoga before your game!” You will slow down your reflexes and reaction times. Basketball players who jump high enough to dunk a basketball need tight hamstrings to provide the “spring” in their step. Why would they want to stretch them out? So I would agree, for that intention, stretches of a minute or more before a game or a run or whatever is probably not a good idea. Myself, I would much rather do some sun salutations to warm up before sports than hold a stretch for a minute. Sun salutations are great dynamic stretches. However, when the situation changes, so does the exercise and its intention.

But these are again yang discussions: the point of yin is not for preparing for a sporting event. The intentions are manifold: to increase ROM, to strengthen joint capsules, to reduce pain, to increase quality of life, etc. You made several points so let me look at some of them:

• “…references to yin tissues, which require prolong stretch, is true for those who want extreme ROM and already possess great strength.” Actually, I use Yin Yoga for people who are distinctly not gymnasts etc. but rather for people who do not have great strength and who are hypomobile. I can use myself as a good example: after two years of Hatha yoga I discovered Ashtanga yoga – for 5 years I would get up every morning before 6 am, do a 2 hour sweaty practice, six days a week, and even so, after 5 years, I could not get my head to the floor in a wide-legged forward fold. Then I discovered Yin Yoga. After adding Yin to my practice, within 3 months, my head was on the floor. My range of motion increased much more dramatically thanks to this style of practice. Yes – it lengthened my adductor and hamstring muscles, which are not typically called yin tissues (although a strong case can be made that 30% of our muscles are fascia and fascia is a yin-like tissue and much more responsible for the tightness in our muscles than the sacromeres.) But the point is – short 1-minute holds were not as effective at increasing my ROM as the longer 5 minute holds. I taught this to other Ashtangis and they discovered the same thing. I have also seen the effect in older students and beginners who within one year have increased their ROM dramatically through Yin Yoga, despite not being physically strong. I am not talking about “extreme ROM” or hypermobility but just getting people who live a sedentary lifestyle back to their body’s natural ROM.

• “I would insist that the stretch of ligaments and joint capsule does more harm than good.” Could be – but we can do too much of anything. Running marathons may be great for some bodies, but would destroy other bodies. Some people have to take care when doing yoga to not overdo it. I am constantly reminding my students of this fact. (See my article on the Goldilocks’ position. However, let’s not err by going too far in the other direction and say, “because you could do too much and hurt your joints, don’t do anything at all!” No stress leads to atrophy: too much stress leads to degeneration. We need to find the middle ground.

• “The asanas, you recommend in your book, stretch the muscles as well.” Agreed! It is a question of degree and intention. Muscles and ligaments are in series and what you do to one you also do to the other. (The fact that are in series is a bit of a new paradigm in medicine: See this article.) But, when the muscles are cool (not warmed up) more stress from the poses goes into the ligament and joint capsules. For this reason we prefer not to warm up too much before a Yin Yoga class, so that most of the stress can go into the yin tissues. (See my explanation of this in YinSights. ) When we engage our muscles or just do yang forms of exercise we “rob” the joints of stress, which in some cases is exactly what we should do, but in other cases is not. When we are undergoing strong dynamic repetitive movements we probably don’t want that stress in the joint, so we engage the muscles to protect the joint. But when we want a stress to go into the joint, it is safer to do this slowly, with relaxed muscles.

• “With age we lose stability due to the loss of muscle strength, if you add to it extra ROM the result is futile.” Yes, but with age we also lose range of motion (ROM)! I am not promoting hypermobility, but just retaining the body’s natural strength and length. Joint capsules shrink-wrap and get tighter as we age. What are you going to do to counteract that if your only modality is to strengthen muscles? We need both – strength, yes – do yang exercise; length, yes – do yin exercises. We lose stability as well, not just due to weaker muscles, but due to weaker collagen structures in the ligaments, joint capsule and bones. This collagen needs to be replaced and enhanced and yin stresses are good at this. We can, we need, to thicken our yin tissues to help them become stronger, not just the muscles.

• “The empirical "feels good" is not good enough.” When I mentioned empiricism I was not referring to “feeling good,” but rather to the actual fact that people do increase their ROM through Yin Yoga, and do so faster than with other forms of yoga. I have not done a double-blind test but the reality of individual cases cannot be denied. That is what I meant by empirically looking at this. But even so – why dismiss helping people feel good? (Back to my placebo point.) To say that this is “not good enough” is a bit arrogant. For the students who have told me how much better they feel after a year of Yin Yoga compared to all pain they were suffering despite the other things they did before Yin Yoga, feeling good is good enough.

• Finally “You might know that the prolong hold stretches (traction) for treatment of disc herniation were proven to be no better than placebo…” I looked at the studies you referred to. Thanks for forwarding them: very interesting. But I also noticed they were always evaluating the procedures against pain. Fair enough, but they didn’t seek to find out if there were other benefits, like increased ROM, better life skills (like scores in the Sit-Rise Test.)

It has been said that 50% of what we think is true now in the field of medicine will turn out to be absolutely wrong in 20 years. The problem is – we don’t know which 50%. This requires us to be humble and open. All we can do is the best we can do with no hidden agendas and with the best interests of our students at heart.

Cheers,
Bernie
Renee
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Location: geldrop

Post by Renee »

I love this discussion. Thanks.
So now that I have learned about Jaap van der Wal I might invite him for a lecture about connective tissue at my yogashala in Holland.
Thanks again Bernie.
Namaste,
Renée
lmm667
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studies on yin type of stretching?

Post by lmm667 »

Hi Bernie - I really appreciate the discussion you shared here. I've been reading various articles on stretching and, not being any type of expert on the human body, I feel a bit overwhelmed and a little confused. Do you know of any studies that have been done that are more in line with what we are doing to the body in the yin postures? It seems most studies are in relation to yang stretching and activity.

thanks,
Lisa
Bernie
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Joined: Sat Sep 23, 2006 2:25 am
Location: Vancouver

Yin studies

Post by Bernie »

Many people have asked me for scientific studies on the safety and benefits of yin yoga type stretches. I don't believe anyone has done a clinical trial of yin yoga, but many studies of yoga have been done. I can't point to a specific yin yoga study (but if anyone knows of any, please tell!) but what I am aware of is lots of studies that show how long held static stresses are beneficial. Your question has motivated me to gather these up and create a posting (probably a Newsletter article) sharing these. Maybe I can get this done for the October Newsletter.
Cristina
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Location: Canada

Post by Cristina »

Hi Bernie,

This debate on static stretching makes me curious about doing yin yoga in a hot room. Since the majority of the stress is being placed on the muscles during a hot yin class then does it become unsafe to hold poses for such a long time? Doesn't this mean that we are holding long static stresses on our muscles?

I am a new teacher and will be teaching a yin class in a hot room and I'm having a hard time understanding what I am really offering people. Yes, I understand that the practice becomes more mindful in a hot room, but is it safe for people to hold poses for so long when it's not really targeting the connective tissues?

Thanks!!
Bernie
Posts: 1293
Joined: Sat Sep 23, 2006 2:25 am
Location: Vancouver

More on hot yin

Post by Bernie »

Hi Cristina

This topic has been explored in other threads. Why not read some of these as background:

http://www.yinyoga.com/forums/viewtopic ... ffd5af90d1

http://www.yinyoga.com/forums/viewtopic ... 437f554ab6

http://www.yinyoga.com/forums/viewtopic ... fa3af80610

Your concern seems to be about stressing the muscles for a long time, but that is what happens in a yin posture. While we do target the deeper connective tissues, we can not prevent stress from also soaking into the muscles. But! The muscles are passive. If they were active that whole time, I would share your concern. But passively stressing the muscles is a common practice in many fitness and dance trainings. Think of ballerinas hold splits for 20 minutes or having their leg up on a bar for a long time. That is targeting the muscles passively, and as a result the fascial bags that envelope and permeate the muscles do become longer, range of motion is enhanced.

For many stiff students, they can only get to a place in a pose where they can stress their joints if the muscles are really warmed up and relaxed, so for them, hot yin is the best thing ever. For a very flexible student, however, she probably isn't going to get any physiological benefits in a hot room, but she can still get mental, meditative and energetic benefits.

Cheers
Bernie
Cristina
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Joined: Mon Sep 08, 2014 11:52 am
Location: Canada

Post by Cristina »

Thank you Bernie!

Yes I did read these posts before but was still a bit confused about it. This really cleared things up for me. I really appreciate your prompt response. I've been trying to do as much research as I could about it, but couldn't seem to find an answer to my question that made sense. You've been so helpful. Thank you. Thank you. Thank you!

Cristina
martyg
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Post by martyg »

Wonderful info. Great to have it all in one place!
Satori44
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Post by Satori44 »

With all due respect to everyone who has contributed to this post, as an Exercise Physiologist I would like to mention a few things which have been neglected here. Chiefly, the concept of static stretching must be approached from a neurological stance as every muscle fiber's length and tone is determined largely by one's sensory-motor system (specifically the alpha-gamma feedback loop). When an equilibrium is reached between the input stemming from the alpha and gamma motoneurons responsible for innervating extra- and intrafusal myofibers, the length and tone of the corresponding motor unit will be established. Therefore, in order to alter any established length or tone of a muscle it is this neural pattern which must be reset. So only considering the effect of mechanically stretching any type of connective tissue (muscular, tendinous, ligamentous, skeletal, or fascial) ignores the fact that the length, tone, and response to stretch of any connective tissue is only partly dictated by the state of the tissue structure itself (by that I mean the number of collagen fibrils present, the degree of elongation or deformation of those fibrils, the pattern of remodeling present and active within the tissue, etc.). In closing, the question which should be asked isn't whether or not static stretching is safe or efficacious, the question which should be asked is why are you inflexible in the first place? A normal, healthy range of motion for every joint in the body is innate unless that has been removed due to the instilling of improper neuromotor conditioning, dysfunctional postural carriage, inadequate nutrition, restraining psychological and/or emotional patterns held within either the fascial matrix or one's auric field, endocrine imbalances, etc. Accordingly, if you truly and completely develop a state of holistic health then your normal joint ranges of motion will return so there is no need to force a muscle to lengthen through any of a number of erroneous stretching techniques. I hope this helped.
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