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The Dose Transcript for March 21, 2024

Host: Brian Goldman

BRIAN GOLDMAN: Hi, I'm Dr. Brian Goldman. Welcome to The Dose. I'm a long term convert to stretching. I've been doing it for decades. And I have to tell you that when I lapse from my stretching routine, my pain, my stiffness in my lower back gets worse. There are lots of questions, though, about how to stretch and when. To me, there's no doubt that regular stretching is great for your overall health, and I'm anxious to talk about this. So this week, we're asking, why should I stretch regularly? Hi, David. Welcome to The Dose.

DAVID BEHM: Well, thank you, Brian. It's my pleasure to be here.

BRIAN GOLDMAN: What's your personal favourite way to stretch?

DAVID BEHM: I play a lot of sports still even though I'm classified as a senior citizen, but I still play tennis and squash and hockey and do some weight training. And so I do a combination of static and dynamic stretching before I start playing.

BRIAN GOLDMAN: Mine happens to be a piriformis stretch because my piriformis and my butt tends to tighten up, and I get a lot of stiffness and pain in my hindquarters that affects my ability to run, and I want to keep running as long as I can. So that's my routine, and we're going to try to impart some wisdom. We're going to get your wisdom to our faithful subscribers. But before we begin, can you give us a hi, my name is? Tell us what you do and where you do it. Just adlib.

DAVID BEHM: I'm David Behm. I'm in the School of Human Kinetics and Recreation at Memorial University of Newfoundland. I'm classified as a university research professor. I've been here, my God, 29 years now, and been doing stretching research. My first publication was in 2001.

BRIAN GOLDMAN: Wow, long time. You are a veteran researcher when it comes to stretching, which is why we have come to you. Why is stretching so important?

DAVID BEHM: Well, stretching is really important because we normally think of okay, we're going to stretch, we're going to increase our range of motion. But it does a lot more than that, and there's a lot of things that people don't realize. So let's start off with range of motion. Well, if you're stiff, it's going to provide a resistance to your movement. So it's harder to move around. So obviously, if we can increase our range of motion and make our tissues more elastic, it's going to increase our movement efficiency. Now, if you've got this really stiff tissue and, you know, let's say it's in your lower back and you bend over to pick up a book or something, stiff tissues can get injured. And so there's less likelihood that you're going to get injured if you have more compliance or less stiff muscle. So that's a really important first reason why we'd want to start stretching. But there's also effects on muscle strength and on cardiovascular, on pain. Stretching does a lot of different things for us.

BRIAN GOLDMAN: Let's start to drill down and find out why. What is happening inside the body when we stretch? One thing is obvious. When you stretch muscles, they get longer. But what else is going on?

DAVID BEHM: A good way of thinking of it is that, you know, you just said, okay, muscles get longer, but they don't. It's not just like an elastic band. An example that I like to give is think of a big truck, you know, and it's at 18 Wheeler. And then you look at its suspension. Now, the suspension has these leaves. You know, they kind of sit on top of each other. There's probably like, I don't know, 10 or 12 of them. And then when the truck bounces, all these 12 leaves have to work together and slide over each other. And so that gives it some like active suspension, I would call it. And so your body is the same. So you've got a muscle and you've got tendons and you have ligaments, and they all have a certain amount of elasticity. So when you stretch, you're going to make them more elastic. So they're going to spread farther. But what's also going to happen is you've got the muscles. And you've got thousands of muscles, so they have to slide over each other. And then those muscles are covered by fascia. It’s a connective tissue around your muscles. And that has to slide over the muscles as well. And then you've got your tendons and your ligaments and they're all sliding. So if you have a lot of scar tissue from previous injuries, they're not going to slide very well. So you not only need the elasticity of each tissue itself, but you need to allow them to slide over each other to give you a greater elasticity to help prevent those injuries and improve your performance.

BRIAN GOLDMAN: In addition to the muscles, we have sensation in our joints that tells us about joint position. Of course, the tech term is proprioception. Does stretching do anything with that?

DAVID BEHM: It certainly does. It enhances your proprioception, again because you've got this tissue that can move through a greater range of motion. So you're not as restricted with this expanse of tissue and this sliding tissue. And so the muscle spindles, or what they call react more efficiently in this more compliant type of tissue and allows you to feel where you are. So that's important, for instance, let's say for balance. If there's a, the big word is perturbation, so if something is disrupting your balance, you're more sensitive to. To it if you have better proprioception. And then if you have something that's going to upset your balance, you slid on the ice, or for instance, this morning, I was walking down the stairs. I was just in my socks and I slipped. So then what happens is I have to react quickly. So I need to get a muscular contraction quickly, but I also have to be able to try to absorb that shock. And so if you can absorb the shock better, you're less likely to fall over. So if you think of something that's really stiff, you give it a push, it's just going to fall over. But if you gave something a push and it's attached to elastics, it'll move and then come back. The next large term we use is meta stability. Meta stability is your ability to be pushed out of position and snap back to its original position.

BRIAN GOLDMAN: What about stretching and posture? You know, certainly, we've seen images of the US President Biden walking around rather stiffly. Now, there may be many reasons for that, but what do tight muscles do to your posture?

DAVID BEHM: That can be a very severe problem, especially in your lower back. So if you've got, let's say, tight muscles in your upper leg, your hamstrings, your quadriceps, as you said, your piriformis, your gluteal muscles, which are your butt muscles, they may be pulling on your pelvis or your hip, and therefore, your pelvis may be rotated in one direction or another. It may be anteriorly rotated or posterior rotated. So your hip bones are facing out too much, or facing back too much, or facing up too much, and then your lower back is in a position so it doesn't have that good curve. You want a nice what's called a lordotic curve. So lumbar vertebrae at the bottom. They need to have a nice little curve because your back acts like a spring. You know, like I said, that 18 Wheeler has those leaves and it's got a nice suspension. Well, your back is your suspension as well. So if your pelvis is tilted because you've got tight muscles in your legs, then it's going to affect all those curves in your back and you're going to have back problems. So very important that you not only have a balance of strength between your muscles in your legs, the contralateral or the antagonistic muscles, quadriceps versus hamstrings, but you also need to have good elasticity or compliance of those muscles. Again, because if one side is too tight, the other side has to work to try and offset how tight that other side is. So you can end up with cramps as well in your legs as well as back problems.

BRIAN GOLDMAN: There's more than one way to stretch. So what are generally speaking, in broad categories, the different types of stretches?

DAVID BEHM: The most common one that we think of is static stretching. And there's two types of static stretching. There's passive static and there's active static. So passive static is when, for example, maybe you're stretching with somebody else and they move your leg up or, you know, move your shoulder for you, and then they hold it in that position for a prolonged period of time. Let's say, you know, 20 seconds, 30 seconds, 60 seconds. So that's passive static. Somebody else is moving you. Active static is when you are moving yourself. So you're lying on your back and you lift your leg up with your own contractions. So that's an active contraction. And again, you're holding that position for 30, 60 seconds or whatever. Then there's dynamic stretching. Dynamic stretching is where you go through the full range of motion, but you're moving dynamically. You're moving continuously through the full range of motion of whatever joint you're doing. Then there's ballistic stretching, which is a kind of dynamic stretching. But there, you're going at very fast speeds. You would never want to do ballistic stretching without a good warmup beforehand. And in fact, mostly only elite athletes should be doing ballistic stretching. Then there's a third one that was really popular back in the 90s and 2000s. It’s still popular now, and it's called PNF. PNF stands for Proprioceptive Neuromuscular Facilitation. Lots of syllables there, but PN F is kind of a combination of doing passive static stretching. And then when you reach that position that, you know, your maximum range of motion, then somebody is helping you or maybe you're using a stretch band, and then you contract against that person or band for six, 10, 15 seconds. Then you go back again and stretch again, and then you contract again. The advantage of PNF stretching is that, you know, if I was doing passive static stretching, I would go as far as I could. And that would be, you know, restricted by my muscle and my tissue, and then I'd hold it there. So definitely, you're going to end up with more elasticity and you'd get a greater range of motion. But the tendon, the tendon is really tough. It's got a lot of what's called collagen fibres in it. And collagen is like copper. Very, very strong. So when you do a PNF stretch and you do that static part, well, the tendon isn't probably being stretched as far as it could. But then what you do is you contract. The muscle shortens, and that really causes the tendon to elongate, to get longer. And it has a greater effect on the tendon than just a passive static. And when you take a look at the research, it seems the two best types of stretches for increase in range of motion are the static and the PNF stretching. You'll still get increases in range of motion with dynamic stretching, but not quite as strong as it is with static and PNF.

BRIAN GOLDMAN: That's a lot of terminology about stretching. In general, is there a right way and a wrong way to stretch?

DAVID BEHM: Everybody's probably heard, you know, no pain, no gain. Normally, you talk about like resistance training, trying to lift, you know, really heavy weights and really putting pressure. Well, the same is true of stretching. You know, the research shows that okay, yeah, we can go to our point of maximum discomfort, you know, it's starting to hurt, and that's going to increase your range of motion. But you don't need to. Maybe Djokovic needs to do that or Simone Biles the gymnast. But the average person can just go to the point of initial discomfort, you know, when they just start to feel some tension, and then hold it there if you're doing a static stretching for, again, 30, 60, 90 seconds, and you're going to get an increase in range of motion. So you could do stretching after you work out and, you know, as part of your cooldown as it's called. But if you're really tired and then your muscles and your tendons are fatigued as well, and then you try and push yourself to the maximum point of discomfort or even go to pain, you're asking for trouble there. You're asking for injuries. If I was to say there's a wrong way to stretch, it's trying to push yourself too far, especially when you're either not warmed up or you're fatigued.

BRIAN GOLDMAN: You know, I want to ask you about the timing of stretching. And I'll tell you, you know, personally, I've been running for decades. There was a time when I would almost religiously stretch prior to every run. And I realized that I could go days without having to do that, and so I stopped doing it. And now I do it more intermittently. And then, I mean, I've met people who've, you know, I've met trainers who've said you should be stretching after, after the run. So which is it? I know it depends on the type of activity you do, but are there some general principles here?

DAVID BEHM: I'm going to be sacrilegious here and say some people don't need to stretch at all. So we've just published last year a paper showing that if you do resistance training with free weights or machines, that you can get a similar increase in the range of motion as you do a static stretching. So I'm a pretty old guy. I'm 67 years old. I've been lifting weights for 50 years. So for 50 years, pretty well, I would stretch before I went into the weight room because, you know, you're supposed to do a warm up, and I thought that was an important part of the warm up and increased my range of motion. Well, you do need to do a warmup before you do your resistance training or your weight training, but it doesn't need static stretching in there. So because the weight training is kind of like doing dynamic stretching with added load, and so you're going to get an increased range of motion with the resistance training. And we've also shown that even by just doing active activities, you know, one way to increase your range of motion is to increase the temperature in the tissues. If you just move beforehand, you'll also get an increased range of motion. Now, that doesn't mean that we shouldn't be doing stretching at all, because stretching is a great way of increasing range of motion. But what I'm saying is that it's not the only tool in the toolbox. You can do stretching, you can do resistance training, you can use different devices like foam rollers or roller massagers or vibration guns or go get a massage from somebody, and they all can increase range of motion.

BRIAN GOLDMAN: If you are going to be stretching, how often per week, say, should you be stretching?

DAVID BEHM: That's a great thing about stretching. Now, again, comparing it back to resistance training, everybody who knows would tell you, well, you shouldn't really workout two days in a row. So if you did your chest on Monday, you shouldn't work out your chest on Tuesday. You should, you know, wait till Wednesday and Thursday because your muscles need time to recover and increase protein synthesis and get bigger and stronger, etc. But that's because when your resistance training, you’re putting a lot of stress on the tissue, and there's usually some micro tears happening that need to be repaired. But stretching is typically lower intensity, so it doesn't have the stress that the resistance training does. You can stretch every single day and not be worried about causing pain or injury to your muscles. Now, that doesn't mean that everybody needs to stretch every day. You can still get an increase in range of motion if you stretch one or two times a week, but I would suggest on average, you probably want to do anywhere from three to six times a week probably would be recommended. And in fact, again, we always looking for the least amount that we can get away with. And there are studies out there that show you could do five seconds of stretching. Five seconds of stretching increases range of motion. Now, does it increase range of motion as much as 30? No, 30 would be better. But yeah, if you say, I don't have time to stretch, well, come on, you've got five seconds.

BRIAN GOLDMAN: I want to ask you about some of the health benefits of stretching. You've mentioned several times that stretching improves range of motion. There's some evidence that stretching can help prevent injuries. And I think I also heard you say it might make you more nimble so that you're less likely to fall. Are those the major benefits?

DAVID BEHM: Yeah, those are major benefits. I just want to make sure that we know. Now, some of the research in the past said stretching does not decrease the incidence of injuries. But the problem with that research was they were looking at what are called all cause injuries. So to give you an example, let's say you're out playing soccer. You're in the field. You're in Regina, Saskatchewan, where all the golfers are, and a golfer had just made a hole in the field. You put your foot in there and you broke your ankle. Well, stretching is not going to stop you from breaking your ankle. Then you fell down and you hit your head on a rock and you got a concussion. Well, stretching is not going to stop you from getting a concussion. Stretching will cause you to have a decrease in muscle and tendon injuries that are usually associated with like explosive or fast movements and change of direction. So it decreases the incidence of those injuries. Then as you mentioned before, it can improve your balance because you're more pliable and you can accept and absorb those different perturbations to your balance, you know, when somebody pushes you or you go off balance. Another area that we normally don't think of with stretching is cardiovascular benefits. So when you stretch, you get decreased arterial stiffness. So the arteries in the veins are less stiff. There's better what's called endothelial function. So the membranes in the veins and arteries, they function better. You get more oxygen saturation. So your ability to take the oxygen out of the blood is better. Even while you're doing stretching, if you're doing it in a relaxed state, you get a decrease in heart rate and blood pressure. So there's a lot of cardiovascular benefits. Normally, we just think, oh, we got to go for a run to get those cardiovascular benefits, but you get those with stretching as well. And then one more thing that I'll mention is that you can increase your strength with stretching. So we've done some studies lately where we've had people stretch their ankle, so their calf muscles, anywhere from 10 minutes a day to 60 minutes a day, and they got increases in strength and in what's called muscle hypertrophy in their muscle size. Their calves got bigger. So you wouldn't think that would happen. But again, you're putting tension on the muscle. And the muscles and the tendons, they react to tension, and they try to protect themselves by getting bigger and stronger.

BRIAN GOLDMAN: Are there any other kinds of activities like yoga, tai chi, that have sneaky stretches within them?

DAVID BEHM: They're all very important and can be another tool in the toolbox. So, you know, if you're not all that keen on stretching, like I said before, resistance training will increase range of motion. Yoga obviously increases range of motion. It's a big part of yoga. Breathing is a main part, but stretching is another main part. As you mentioned, tai chi and just movement. We did a study just a couple of years ago. Your viewers may be familiar with this tool called the Foam Roller. And we found that foam rollers increase range of motion as well, and in some cases, just as good as static stretching, at least in a single session. Now, we thought, okay, that's great. But then we thought, well, what if instead of foam rolling, we just have the person put their feet on a roller that rolls back and forth? So there's no rolling on the muscle. The person just pretends to roll. And we compared pretending to roll, which was called the sham situation, to actually doing foam rolling where you're putting pressure on the muscle. And we found both provide the same or similar range of motion. So just pretending to move back and forth and pretending to roll your quadriceps and hamstrings provided a similar range of motion to actually using the foam roller. So the movement itself increased the muscle temperature. They got an increased range of motion. So there's lots of ways of getting an improvement in flexibility.

BRIAN GOLDMAN: Final question I wanted to ask you. There are people listening to us who don't stretch, haven't stretched. What's one basic kind of stretch that you would recommend for somebody who's just starting out?

DAVID BEHM: An easy stretch would be a forward lunge. So all you do is you step forwards, and then the leg that went forwards, have the knee at about a 90 degree angle. And when you lean forward as much as you can, the back leg is straight. That stretch itself would stretch your quadriceps, the front of your leg, would stretch your gluteal muscles, your butt muscles, stretch your hamstrings. And then if you did it to the side or even at a 45 degree angle, you would stretch your groin muscle. So with one stretch, you could do most of your lower body exercises. And for some people, it's hard to get up and off the floor. So, you know, to get down on the floor or on your back, switch over. With a forward lunge, you're still standing up. So it might be better for people who, you know, have difficulties in that manner to get started.

BRIAN GOLDMAN: David Behm, you're obviously an expert in stretching and research related to stretching, and thank you for sharing your expertise with us on The Dose.

DAVID BEHM: It was a pleasure to have the conversation today. I really appreciate you inviting me.

BRIAN GOLDMAN: David Behm is a university research professor in the School of Human Kinetics and Recreation at Memorial University. Here's your dose of smart advice. Stretching is used by elite athletes, people of all ages who take part in fitness programs, as well as patients in rehab programs. Stretching lengthens tight muscles. It helps muscles, tendons and ligaments glide more smoothly over one another. It increases range of motion, improves posture and makes you more nimble, which means you're less likely to fall. Stretching also helps patients with chronic neck and back pain. There are several different kinds of stretching. Passive static stretching means using your hands, an elastic band or a partner to stretch out a muscle. Active static stretching means you stretch the muscle by contracting it. Dynamic stretching means gently repeating a motion several times while increasing the range of motion. For example, extending your arms to the sides and drawing small circles in the air with your hands. Precontraction stretching is a three step sequence. Step one, stretch the muscle. Step two, contract the muscle against resistance while it's still in the stretched position. And step three, stretch the muscle some more. The resistance is provided by a partner or an elastic band. For general fitness, the American College of Sports Medicine recommends active warmup, followed by static stretching at least two or three days per week. Each stretch should be held 15 to 30 seconds and repeated two to four times. For older adults, up the stretch time to 60 seconds. Stretch to the point of mild discomfort. It should never be painful. Avoid stretching limbs that are broken, have soft tissue injuries, or are inflamed or infected. Avoid stretching if a bone spur or some other factor blocks range of motion, and don't stretch joints that are very loose or lax. You don't have to be a fitness buff to stretch. At home or at work, if you stretch, you'll notice the benefits. If you have topics you'd like discussed or questions answered, our email address is thedose@cbc.ca. If you liked this episode, please give us a rating and review wherever you listen. This edition of The Dose was produced by Sameer Chhabra and Isabelle Gallant. Our senior producer is Colleen Ross. The Dose wants you to be better informed about your health. If you're looking for medical advice, see your health care provider. I'm Dr. Brian Goldman. Until your next dose.

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Why should I stretch regularly? - Transcript

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