Sometimes we might consider that the actual speed of movement can vary nicely based on the different exercises that we perform.

So this becomes the best thing you can do for yourself. Let’s reduce that risk of injury by controlling the speed of movement whenever we can. Welcome to the Strength Changes Everything podcast, where we introduce you to the information, latest research, and tools that will enable you to live a strong, healthy life. On this podcast, we will also answer your questions about strength, health, and well -being. I’m Amy Hudson. I own and operate three exercise coach studios.

My co -hosts are Brian Sagan, co -founder and CEO of The Exercise Coach, and Dr. James Fisher, leading researcher in evidence -based strength training. And now for today’s episode. Welcome back to the final installment in our series called principles of exercise design. We really hope you enjoyed this series. And just as a recap to some of the topics we’ve covered here in these past six or seven episodes, principles of exercise design, we covered a warm up, do we really need to warm up? Is it necessary before strength training, we talked about muscle fiber recruitment, why that is an important piece of a workout that’s effective.

We talked about recovery and why recovery is actually just as important to achieve the adaptations we’re after. We talked about exercise order and how we select exercises to do in specific sequences and some of the considerations behind that. We talked about effort, so why high effort is so important. in your workout. And today’s topic is going to be on speed of movement. And so Dr. Fisher is with me today.

And so Dr. Fisher, this is the final topic in our series, principles of exercise design. Let’s start off by sharing with our listeners, what are we talking about when we’re talking about speed of movement?

And

how does this relate to our series on principles of exercise design.

Yeah, so when we talk about speed of movement within a strength training, what we’re effectively talking about is the time it takes to perform each of the phases of a repetition. So the concentric phase is the lifting of a weight or the shortening of a muscle. So in a chest press, for example, or a leg press, it might be your hands or your feet moving away from your body. So And then the eccentric phase is the lowering of the weight or the lengthening of the muscle. So that would be your hands or your feet coming back towards your body. And we often use the phrasing of speed of movement, you know, to reference how fast you’re going.

But in fact, it’s actually difficult to talk about it in that term, because For the most part, people don’t know how far they’re moving and they don’t know the time that they’re taking to move that distance. And of course, speed is actually a factor of distance and time. So in many cases, we often talk about repetition duration or repetition tempo or things like that. Now. In fact, with the exerbotics devices, we can say exactly speed of movement because it’s isokinetic. So we know the exact distance it’s moving and we know the exact speed it’s moving.

So with our exerbotics devices of the exercise coach, we can know the exact speed. But for anybody using any other equipment, it would be repetition duration or repetition tempo. And it’s typically talked about in terms of two to three second concentric or three to four second eccentric, up to 10 seconds, 30 seconds, you know, however slow or fast a person is planning to move. Now, again, with the Exabotics devices, it’s pretty -controlled by the program that we’re using. So it’s then at a controlled tempo.

So it might be a four second concentric and a four second eccentric or an eight or 10 second concentric and eight or 10 second eccentric phase.

So that’s what we talk about when we talk about speed of movement and rep duration and things like that.

Okay, great.

Okay, so why is speed of movement important then as a consideration when it comes to an effective exercise routine? Yeah, so this is probably the key question. And lots of people have posited over the years that you need to be able to move fast in sports, you need to train fast in the gym. So there’s this kind of idea that to produce power, you need to move fast within the gym environment. In fact, it’s actually been shown, there was a paper from 1993 by our colleague, Dr. Dave Beam, who of course has been a guest on the show. And the paper was titled, Intended Rather than actual movement velocity determines velocity -specific training response.

So what he was saying or what he showed in that paper is it’s actually the intent to move fast rather than actually moving fast. So when a muscle is fatigued and it can’t move fast, but we’re still trying to provide that stimulus to move fast, then that’s what helps us to increase our power or increase our strength in that way. Now, of course, with the exerbotics devices, where the pace is controlled by the movement arm and by the computer, we can push as hard as we can. And that’s an intent to move fast. But of course, the movement arm will never move any faster. And so it’s a controlled pace throughout.

So it’s a really interesting concept that historically people have thought, well historically, even some people today still think that you need to move fast to produce power, but it’s actually not the case at all. And in fact, sticking with a bit of a research theme, there was a paper more recently by Brad Schoenfeld’s group, and they basically did a meta -analysis looking at muscle adaptations, so hypertrophy adaptations, looking at all the different studies that have looked at repetition duration, and they found that there’s actually absolutely no difference in the muscular adaptations, whether you move very fast or whether you move very slow. The key thing that we can then move into is to then bear in mind the safety element of lifting weights. And of course, if we’re moving fast, then we’re potentially out of control with our movements.

If we’re moving slow, we’re maintaining muscular tension and we are within control. Absolutely.

So what you’re saying is that the slower speed of movement isn’t so much important for strength gain purposes, but it’s important for safety. I imagine you’re about to flesh that out a little bit more. I am indeed, yeah. So for those of you who are watching on YouTube, I’ve got a video that I’m going to click through in a second, and I’ll obviously do my best to narrate this as we go through for people listening on the podcast. But this was back at the university I was based at, and I’ve got a a student here who is doing push -ups on two force plates one under his left hand and one under his right hand and on the video as you’ll see if you’re watching he’s doing very slow very controlled push -ups and i i think i guided him to try and do 10 second eccentric 10 second concentric push -ups um if you’re still watching then then you’ll see he’s not even finished his first full push -up yet he’s just recently the end of it and now he’s beginning the eccentric phase of the second so if we click and look at the actual forces produced by this by this exercise we can see we can actually first of all see an orange bar and a blue bar going across the time duration and and we can see this was a 24 second push -up so it was about 10 second concentric and 10 second eccentric and through that full repetition His forces were between 600 and 700 Newtons.

So remembering when you do a pushup, it’s not your full body weight, it’s the body weight resting through your hands, but it was a force of about 135 to 160 pounds through the force plates. So it’s nice and consistent. It’s a nice steady curve. There’s no peaks. It’s a gradual increase, gradual decrease based on the simple biomechanics of doing a pushup. So that’s what we like, that’s what our joints like, that’s what our muscles like, it’s constant tension, it’s constant loading, there’s no high or low forces.

So I then asked him to do 10 push -ups much much quicker and so those of you watching on YouTube will see he’s now doing 10 push -ups effectively one push -up per second. And he’s just going up and down on the force plates and we can, there we go, it’s reached the end of the set of repetitions there. And if we now cut to the figure that that produces, we can now see quite drastic, quite a drastically different figure. So again, we can see the forces through each hand, but we can also see the peak forces of his total body weight through the pushups. And they now start at 600 Newtons, which is effectively his bodyweight on the platform.

But when he descends down now, it drops to nearly 200 newtons. That’s only about 45 pounds. And then as he pushes and does a very, very explosive push -up, it peaks at 1100 newtons which is closer to 250 pounds and it proceeds to do this up and down in 10 drastic decreases and drastic spikes with each push -up. Now many people will look at this and say oh that’s great that’s 1100 pounds of force that’s 1100 pounds of 1100 newtons of force through his muscles so that’s what you want to load the muscle. Well, if we remember, there’s actually no more load through the muscle because it’s the same person doing the same weight for the pushup. He’s just moving quicker.

And hence why that it’s up and down in such a way. So for every time it drops. it rises the equivalent amount but the problem is that we have it in very very drastic peaks and troughs so we can see there that it changes from 45 pounds or 200 newtons to about 250 pounds or 1100 newtons in less than half a second. And those forces are not just through his muscles, those forces are also through his elbows and through his shoulder joints. So if we bear that in mind, that’s not what we’re looking for, for healthy joints. Those forces are through his ligamentous tissue and tendons and wrists and so on and so forth.

So based on everything that we’ve said that There’s no difference in rep duration for adaptations.

You can move faster, you can move slow, and you’ll get the same strength or the same hypertrophy adaptations, and certainly the same health benefits as far as

myokine release, metabolism, expenditure, and so forth, what we can actually see is moving slower is much, much safer for his joints and his tissues as he performs the exercise. For sure. Seeing it this way makes a lot of sense. There’s these great big peaks. And so what you’re essentially saying is that His joints and his muscles are basically toggling between 45 pounds and 250 pounds quickly a bunch of times during this push -up set. And obviously, you know, we don’t want really light and really strong forces back and forth.

It doesn’t take a rocket scientist to see how that’s not safe, right?

Or as safe for our joints and muscles as a steady force, consistent force that isn’t so extreme back and forth over time. Seeing it this way makes a ton of sense, you know, in terms of making this point. Yeah. And what we can think about is if we, if we extrapolate the speed of movement into something like a vertical jump. So if I jump up and then I land, well, the jumping phase can be good. Okay.

We can think about that as high force production for the muscles. It’s not necessarily high, high forces around the joints. The high force around the joints comes when I land. So, I can push off, and that’s great, but what goes up must come down. And it’s when I make that catch, or when I try and land, that’s when there are very, very high forces through the joints that we really want to avoid. So what we should be thinking about with resistance training is it’s there for safety.

It’s there to improve our health.

It’s certainly not an activity we partake in that should have any risk of injury by its very definition. if you get injured doing resistance training, then you’re not improving your health, you’re diminishing your health. Absolutely. We don’t want our exercise to make us worse off than we were before we engaged in it, right? It’s supposed to improve our functionality, not decrease it.

And so if my exercises creating or causing injuries in my joints because of the explosive forces in it or because of the speed at which I’m doing it, am I actually really doing myself any favors by that exercise? And that’s one of the big barriers people have to participating in the first place to exercise is because it’s not safe. And so, yeah, let’s reduce that risk of injury by controlling the speed of movement whenever we can. So the other final thing that we can think of is, is there any reason why we should use different rep durations? So a four second concentric, four second eccentric, or an eight second concentric or eight second eccentric, because there are multiple different protocols at the exercise coach that many people will have used. And a couple of reasons that I would say around the benefits of using different rep durations is first of all, the psychological stimuli of moving at a different pace.

I think it keeps us interested. I think it’s novel. I think it keeps us engaged in maintaining that muscular tension. So we might do longer time under load or longer rep durations or shorter time under load and shorter rep durations and so forth. But we can also think about it in terms of different exercises and the different range of movement for different exercises. So for example, our hip abduction and hip adduction is a relatively small range of movement, probably 45 degrees ish on each leg as we move into abduction and so forth.

Whereas when we do a chest press or a leg press or a press or so forth, we’re moving our shoulders and our elbows through potentially a far greater range of movement. So the greater the range of movement, if we’re moving equally slow, it can feel like an absolute lifetime if we’re moving very, very slow through a large range of movement. Whereas if we move at a shorter repetition duration for a small range of movement, it feels relatively quick. So sometimes we might consider that the actual speed of movement can vary nicely based on the different exercises that we perform. And a great example for this is the low back.

The low back is not a large range of movement. Lumbar extension is not a large range of movement. So generally moving slower on that is far more favorable than moving quickly. Absolutely. That makes a lot of sense. And if you’re an exercise coach client, your coach can literally tell you, you know, this this protocol that we’re doing today has a four second concentric and a six second eccentric.

And here’s why. And here’s your goal on this exercise. And this is what it’s designed for. So it’s pretty cool.

With the click of a button, being able to give somebody a physical experience that’s tailored to not only safety, but the efficacy and the motivation for that person to follow the goal that we’ve set for them that day and continue to see that progress.

So I love that. So basically, you know, Dr. Fisher, if I’m a coach listening to this or a trainer, what are the main things that you want me to keep in mind then when it comes to delivering a workout to a client and what I coach them to do and how I frame that to them? Yeah. So the key thing for me is there should be sustained, continued muscular tension throughout a repetition. And it should be obviously with the exercise coach, with the exerbotics devices, there’s a traced follow.

There’s the green line to track. And we’re trying to maintain continued forces throughout the range of movement through to full extension, through to full flexion, without that rest pause. We’ve talked about intensity of effort. We’ve talked about if you let that bar drop to zero, that’s effectively a rest. You’re allowing muscle fibers to recover.

Well, as we talk about speed of movement, we can also talk about maintaining that force and maintaining that tension.

Now, obviously, you should be breathing continuously throughout, there shouldn’t be a valsalva maneuver, but it should be about, you know, looking at the total time under load of, you know, 90 seconds or two minutes, whatever it might be, and planning to have high force through that time, through that range of motion for every single repetition, but it should feel almost rhythmical, it should feel steady up and steady down. And it should feel like, you know, like I said, like a continued effort. Absolutely. Well, thank you for that. Yeah. And you know, just from a client perspective, I mean, if you’re a person who’s over 50 years old and you’re starting to worry about bone density and you’re starting to worry about joint health, you want to find an exercise program that is joint friendly, that’s not surprising you with heavy loads, that’s not pounding the joints.

And so this becomes the best thing you can do for yourself in order to fight the muscle loss that you might have. build that bone density up, feel your best, function your best. And so I hope today when you listen to this episode, it really solidified your understanding of why this is an important piece of your exercise and the safe and effective exercise that we’re going for. Thank you for joining us with this series. And we look forward to next week on the podcast when we start off a new series all about health and nutrition. We will see you next week.

And until then, we hope you remember strength changes everything. Thanks for listening. If you enjoyed today’s episode, please share it with a friend. You can submit a question or connect with the show at strengthchangeseverything . com. Join us next week for another episode and be sure to follow the show on Apple Podcasts, YouTube, or wherever you get your podcasts so that you never miss another episode.

Here’s to you and your best health.