CPT Fitness stretching NASM CPT Podcast

The Integrated Flexibility Continuum (NASM CPT Podcast)

National Academy of Sports Medicine
National Academy of Sports Medicine
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NASM provides an integrated model of flexibility that includes corrective, active, and functional flexibility categories. The specific techniques used within the Integrated Flexibility Continuum are as follows:

Integrated Flexibility Continuum

Corrective Flexibility

Designed to increase joint ROM for shortened muscles. It is specifically for the areas of hypomobility.

This, like the other phases of the continuum, is especially helpful for athletes. Like baseball players, for example!

Active Flexibility

  • SMR/SMT/Foam Rolling
  • Active Isolated Stretching

Functional Flexibility

  • SMR/SMT/Foam Rolling
  • Dynamic Flexibility

This episode talks about just because muscles “feel” tight doesn’t mean that they are in fact tight. Assessments are to be done to identify shortened muscles verses lengthened muscles. In an integrated model the progression from on type of flexibility category to another should be aspired to. As initial limits in ROM begin to increase through corrective strategies, more active techniques can be applied to provide strength to the new found ROM.

Just like in the OPT model, once strength gains are made, speed can be applied. In this case, functional flexibility can include dynamic flexibility techniques where momentum and speed are added to the stretch. This integrated flexibility continuum is a brilliant, yet simple model to follow to support our client’s flexibility needs. 

Also read this resource for the relevance of flexibility training

Key Terms: 

Muscle Spindle = “Stretch-O-Meter”

Golgi Tendon Organ (GTO) – “Tension-O-Meter” 



Welcome to the NASM-CPT Podcast, my name is Rick Richey and today we're gonna be talking about the NASM Flexibility Continuum. This Integrated Flexibility Continuum. That means we're not just picking one thing because we like that thing, it's that we're taking flexibility concepts, putting them together, putting it in a continuum, and making it make sense for your clients depending on where they are.

Now when I was a young man, I did martial arts. I still do martial arts, but I did martial arts where we focused a lot on acrobatics and gymnastics, and I was able to do that sweet little Jean-Claud Van Damme splits between two chairs move. That's right, I was able to do the center splits between two chairs, I could do the front splits on both legs, yo I had skills! No joke, this was amazing; looking back at that, I am amazed that this body was once able to do stuff like that.

You talk about if you don't use it, you lose it, so that was a long time ago, but being able to do that gave me an understanding of flexibility that many people will never comprehend, but it also didn't set me up to truly understand what flexibility was and its purpose. It was important to me because I wanted to be able to do the splits, and I wanted to be able to kick really high, and I wanted to be able to do these really dynamic-looking exercises, but the functionality of it was really not truly explored.

Now it was important for what I was doing at the time, so we need to make sure that we understand that we may support people in something that they have efforts towards. For instance, people who might need flexibility for their craft or their art, certainly martial artists come to mind. Dancers comes to mind as well. But are we helping our clients get into this range of motion, are we thinking that all of our clients need to have this incredible range of motion? I don't think anybody thinks that, but that might be a goal of somebody's.

You also want to understand why they have those goals, and if we have those goals we can help support them in reaching it, maybe some of the stuff we'll talk about today helps. But also, we need to understand that I might have somebody that I'm training that wants to be flexible, but if you look at 'em they actually need to increase their stability, and they don't wanna lose their stability because of this hypermobility.

If I have a hypermobile client, and they tell me, and for no reason so they're not doing martial arts, and they're not dancers, and they're not doing other things that this is important for, and they're just saying, "Hey, my hamstrings feel tight, they feel tight." And then you go to stretch their hamstring in that 90-90 position, and they right up into that position. And you go back and they're like, "Push it back towards my head, I wanna be able to kiss my thigh," or whatever it is. And they don't need you to stretch them. They may need to increase some stability, but looking at that range of motion, and sometimes what we refer to as naive flexibility or flexibility without a purpose, so you wanna be very aware that you're not creating, potentially, any contraindications by overstretching someone.

And of course if somebody's telling you that they feel tight, we wanna understand also that feelings are not facts. And just because something feels tight doesn't mean that it is tight. It's not mechanically tight, certainly, in this situation. Neurologically it might be tight, because it is doing something to, probably try to stabilize a joint, so neurologically it's becoming very active.

Read more: Hamstring Flexibilty Through Core Stability

The Flexibility Continuum

So base everything that you do off of thorough assessments. Now let's talk about the Flexibility Continuum. I like this because, well one of the brilliant things about the OPT model, it's the simplicity. And the Flexibility Continuum goes really well with that stabilization, strength, and power phase, and you've got three different versions of flexibility that we're going to look at in the Integrated Flexibility Continuum.

There's corrective flexibility, active flexibility, and functional flexibility. Now these are headliners, these are the topics, the types of flexibility that we wanna help people get and maintain. There are techniques that allow us to get there. Every one of these across the board, whether it's corrective flexibility, active flexibility, or functional flexibility can all use what NASM refers to as self-myofascial release, or what's commonly referred to as foam rolling.

Self-myofascial release

So you can use foam rolling in any one of these modalities to help with corrective flexibility, to increase active flexibility, and to provide functional flexibility, so foam rolling across the board. If you were like, "What should I do, in terms of flexibility?" And you were stuck on an island, and you were only given one option, which in this example doesn't make any sense because you can do corrective flexibility, active, or functional if you're stuck an island, but I think you understand if you could pick one thing, foam rolling might be one of those things that it's just highly indicated regardless of which section that you're in. You can do it across the board, so it's highly indicated regardless of what your flexibility outcomes are looking to be.

Now, one important thing to understand about corrective flexibility is we start to identify what falls underneath it. Corrective flexibility is designed to increase joint range of motion, that's really its purpose. I wanna increase range of motion at a joint. It can help to improve muscle imbalance, why? Because we're limited in our range of motion. And it can help to correct altered joint range of motion.

So there might be this arthrokinetic imbalance that's taking place, and it's gonna help with how, potentially we can, our muscles can glide, and how they can roll. So be aware of that, and understand that corrective flexibility is really to correct imbalances. Now that goes back to this conversation we're having about somebody that's really flexible and you give him perhaps that hamstring stretch and they say they feel like they need it, but when you look at them, they don't need that. They're incredibly flexible, they're hyper-mobile, or overly mobile.

Corrective Flexibility

Corrective flexibility is designed for people who are hypo-mobile, people who have lower mobility, and decreased range of motion. The only time that I would suggest potentially doing static stretching for somebody that might have already increased range of motion might be after a pretty intense workout and those muscles truly are tight, and they're potentially getting quite sore, then that stretch can help to create an inhibition that causes those muscles to relax a little bit.

So corrective flexibility, you have two things. You have the self-myofascial release, you've got static stretching. Self-myofascial release, or foam rolling, and static stretching. Static stretching, you're gonna take that stretch, and you're going to hold a stretch for a minimum of 30 seconds, and I tell my clients all the time, you may need to do more than 30 seconds. You may need to do 60 seconds. And the only reason I tell them that is because they do that one, two, skip a few method, so they're not really doing 30 seconds, they're doing about eight seconds, and they go, "oh that had to have been 30 seconds." So sometimes I'll tell them to do more.

And there's actually a wonderful study that showed several different people within a research study where they did either 30 seconds, and then they did up to a hold of 120 seconds. And the 30 second hold group was just as effective as the 120 second hold group. Now what's happening here?

Usually what happens is, we're looking for not just a mechanical extension of the muscle, but we're looking to get the muscle neurologically to release and so, or to become inhibited. And this term is called autogenic inhibition. Autogenic inhibition in a static stretch is you are statically stretching a muscle, let's say hamstrings, 'cause that's a common one that people talk about. So you stretch the hamstrings. When you stretch the hamstrings, the hamstrings get tight. They don't like being stretched. There is a mechanoreceptor in the body; as you start to lengthen a muscle, depending on the length or how much you lengthen it, and how fast you lengthen it, this mechanoreceptor will see that and then it'll go, "I don't like that, I do not like what this feels like."

So that stretchometer that's in there is going to be the muscle spindle. And the Golgi tendon organ is a tensionometer. It's measuring the amount of tension. So as we stretch and that muscle spindle stretches, whether it's overly lengthened or quickly lengthened, it starts to tighten up, and it says, "Man we're gonna hurt this muscle if we keep stretching." Well after about 30 seconds, the Golgi tendon organ is feeling this tight muscle, and it's going, "Man if we keep stretching this, and I don't relax, we might hurt this muscle." Or it might be looking at it and say, "I feel we've been here for a while, it seems kinda safe to me, so let's just relax the muscle right now because I think we're cool. We're absolutely fine."

And so the GTO might allow for relaxation, and the spindle and the GTO are within the same muscle, this is autogenic inhibition, causing the muscle to relax when you do things like a static stretch, and also the similar thing that happens when you're doing self-myofascial release, or foam rolling, or aka roller massage, you're gonna get the same outcomes. You're gonna get this autogenic inhibition. Well that's it for corrective flexibility, it's appropriate at the stabilization level.

So again, kind of the brilliance of this entire set-up is that we can take our Flexibility Continuum, our Integrated Flexibility Continuum, and then we start plugging it in. Now there's some people who will look at static stretching and they say, "Oh, I don't like static stretching; static stretching doesn't work." Static stretching this, static stretching that. Clearly there's some, some stretch bias that's going into there, 'cause there's plenty of research that shows that static stretching works at increasing range of motion. But why are you trying to increase range of motion? I think that we need to always have that in mind. But the other thing that happens, when we look at corrective flexibility and static stretching is that, yes, there's research, plenty, that shows that it works to help increase range of motion, but why would somebody look at that and say it doesn't work? Well it might be because of the benefits that come from active stretching. So we have that, we do that also.

Active Flexibility

We have active flexibility as a component of our Integrated Flexibility Continuum, where we'll do active isolated stretching. And what we don't do, is we don't say, "Hey, there's active stretching and there's static stretching, pick one, what's your favorite?" And then downplay the importance of everything else. I look at that and I say, "Man, there's a serious flaw in what you're doing." That's a serious flaw. What that is, is that you're not looking at the whole picture. You go in and you look at a painting, and some paintings have really, really wonderful designs in it, but if you're standing up really close to the painting all you might see are a bunch of dots. And then you back away slowly, and those dots start to create a bigger, a more fluid picture. A richer picture of understanding, and that's what I think we should look at here, instead of arguing which is better, and just because I choose this one the other one doesn't work, what we should be doing is finding out who is this for, and what are the benefits for? And if there are benefits in every single bit of self-myofascial release, and static stretching, and neuromuscular stretching, and active isolated stretching, and dynamic stretching, then why would we exclude anything?

This is an integrated model, and as we start to figure out what are some other means of flexibility that are valuable, they'll start being integrated into the model as well. Because they have value, they have a purpose, and they follow along within this integrated concept.

So, once you've moved on from helping to assist somebody with increasing their range of motion, now what you wanna do is you want to apply strength to their new-found range of motion. So if you don't apply strength to it, you have to continue to statically stretch it in order for it to maintain its new range of motion. Well, I want to provide strength to my new range of motion. If I can provide strength to it, it now has function. It now has a purpose.

So a great example I like to do is clearly, we may talk, or you may hear a lotta people talk about tight hip flexors. People sitting in a chair, and their hips are in a flexed position, and the hips become adaptively shortened into that hip flexed position. And we wanna say, "Well now I need to provide some strength, maybe, to my hip extensors. So I've got a new range of motion, from my corrective flexibility, in my hip flexors, and now I'm going to use my hip extensors in active isolated stretching to pull me into a new range of motion."

So that stretch, that static stretch a minimum of a 30 second hold; with an active stretch you're not looking at something nearly that long. You're looking into going into that range of motion, holding it, maybe hip driving, squeezing the glute to get a hip extension, to stretch those hip flexors, and to be honest, the goal of this, you shouldn't be looking at this and saying, "Hey, I don't feel my hip flexors stretch." Not the point, that's not the point. The point is getting the hip extensors to move you through it, so this is no longer about the muscles you were working with corrective exercise when it comes to like, did I feel that muscle?

It is now about feeling that you're going through that range of motion and your hip extensors are taking you through hip extension, and the hip flexors are agreeing to go through that motion. You might have clients where you have them do a floor bridge, and when they do a floor bridge they rub the front of their thighs, and they say, "But I feel it here." Well, those people, that's a great active stretch for them, because they're getting an actual stretch in the rectus femoris, but also making sure that the glutes are your primary hip extensors in that, and that it's not hamstring-dominant, because we don't want to go through this active flexibility and start to create a synergistic dominance situation. We want the primary extensor to be the primary extensor, we want the synergist to be the synergist.

So active flexibility provides strength to your new range of motion. It's gonna increase your neuromuscular efficiency, and it's going to do this via something called reciprocal inhibition. Not autogenic, reciprocal inhibition. Autogenic inhibition, it's gotta be held for how long? That's right, about 30 seconds. Reciprocal inhibition is, think about in math classes we had fractions, there's a numerator and a denominator and if you wanted to multiply out of it you had to get the reciprocal. Reciprocal just means the thing on the other side.

So reciprocal inhibition, the glutes are the thing on the other side. That's the muscle that you may want to really activate, and when that happens, the muscle on the opposite side ideally is going to now relax. If not, you've got something called altered reciprocal inhibition. And so what we wanna do, is we want to provide length to the short, tight, overactive muscles, and then provide strength to the opposing muscle groups. So now we can work through a new-found range of motion, and provide strength into that new-found range of motion. That's the value of active flexibility, and it's something that's undervalued in a lot of training.

So you personal trainers that are out there, you CPTs that are out there doing the thing, I love that you're foam rolling. I love that you're doing static stretching to increase range of motion, but y'all, let's start getting the active flexibility in there. Start taking them through active flexibility exercises, and do several repeats, because this is done in the strength level and the value of this is because even our flexibility is a strength-training exercise here. We're providing strength, activation to the glutes prior to going and doing a leg-based, glute-based exercise like a squat or a dead lift.

So now I'm gonna go through my active flexibility as prep-work for my strength-training, which is beautiful 'cause it's just a bunch of activation exercises for muscles. We'll refer to it here right now as active flexibility, but they're activation exercises. And then finally, when you ever hear studies that say, "Oh static stretching, don't do that because it limits how fast you're going to run." Y'all I get that, but remember, static stretching is designed to increase range of motion and it's generally done in phase, or level one of the OPT model. If you're in the top level, level three, the power level of the OPT model, you're not doing corrective flexibility, most likely, unless you've got a severe and kinda clinical imbalance. You're not doing active flexibility, you're doing functional flexibility.

Dynamic Stretching

Functional flexibility, yes, you can use self-myofascial release or foam rolling, but then you've got dynamic stretching. Dynamic stretching is the technique that is applied. Dynamic stretching can be leg swings, right? Those hamstring swings, it can be leg swing back for this dynamic hip flexor stretch. There are these side to side swings for your ab- and adductors. But you can do squats. And though that's not as incredibly dynamic, it is certainly functional, and really functional flexibility, what we're trying to get out of it is the ability to do that squat. And to be able to do that squat in better form, and every time you go through a range of motion in a functional exercise, you need functional flexibility to do that. So it's all appropriate, whether you're doing corrective flexibility, or static stretching, whether you're doing active flexibility as a technique, active isolated stretching, or functional flexibility for dynamic stretching, adding your self-myofascial release or your foam rolling in there, but finding where your clients are, or where you are personally in what type of flexibility you should be working on.

All right y'all, thank you so much. My name is Rick Richey, you can hit me up at Rick.Richey@NASM.org. Holler at me, let me know what you thought of this podcast, and if there's something else you want me to talk about or speak on that I can help support you with, let me know. This is the NASM-CPT Podcast.

The Author

National Academy of Sports Medicine

National Academy of Sports Medicine

Since 1987 the National Academy of Sports Medicine (NASM) has been the global leader in delivering evidence-based certifications and advanced specializations to health and fitness professionals. Our products and services are scientifically and clinically proven. They are revered and utilized by leading brands and programs around the world and have launched thousands of successful careers.


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