Backwards Running, Eccentric Cycling, & Wearable Resistance

Aaron Uthoff1:22

But I started looking into the research and it's not a whole hell of a lot of it out there. But what was out there was starting to get really compelling. We were looking at muscle activation patterns, looking at patellofemoral compression forces. You're looking at there's a couple of studies by Turblanch at all that looking at the effects of backwards running on agility training and speed and things, and what was actually coming out of it. Looks like there was a unique adaptation.

And so I kind of went to a bit of a rabbit hole and was looking at kind of central pattern generator. So how our body moves, the neural networks and things like that. And so when I started looking at this research by Hookhammer and all and starting to look at some work by Kavanaugh, and we actually look at there's a shared circuitry that runs your body for locomotion and the more variety of locomotion you get the stronger that circuitry actually becomes, the more fluid you become at these movements.

So this high movement variety actually translates to a shared circuitry which improves basically activation to the musculature. And so it was awesome. And then I dove into Kavanaugh stuff and what they looked at was basically you got a typical stretch shortening cycle which is pretty much got a hard, a high braking force and then a slower propulsive phase at high speed velocity running.

But when you look at it with backwards running, we actually see a slightly longer braking phase with slightly lower braking forces and higher propulsive forces. So instead of this hard landing, soft takeoff like you see forward, we actually see a soft landing, hard takeoff, which means that we're using the muscles, the fascia, the tendons, everything's working in just a slightly different manner. So we're getting unique adaptations from it. So that's basically what created this backwards running PhD and route that we went down.

James de Lacey4:45

Dude, that's super interesting. What might be even more interesting to go further into is more the application side because you cover a lot of, okay, maybe some of the reason why we're kind of looking at it and we'll go probably further deeper into it too, but I think it would be good to even start with the application of when, why, and how would you even implement this? Like what scenarios do you see where running backwards even makes sense in a training program?

Aaron Uthoff5:12

Yeah. Well, I guess let's look at it beyond a training program. Let's look at it in a real life situation. So rugby league, rugby union, American football, and soccer, or for those European or the rest of the world, football, we see that between 3 and 7% of a match is conducted running backwards in some fashion.

So we have to take that application and put it into a field scenario. And so when we look at that, we realize that this backwards or unique or weird locomotion pattern is actually utilized in key critical phases of having to get move from a defensive phase into an offensive position or getting yourself into and out of a correct position. So from an actual application within the sport, you've got that.

And then from a training perspective, again, we have to be moving in a bunch of different patterns. You look at a defensive back and we've got a defensive back, linebacker, things like that, and they're always moving in and out of different locomotive patterns, whether it be a backwards run, a shuffle, karaoka, crossover run, and a sprint. And so, you have to have that coordination pattern. So from that perspective, we got it.

When we start looking at training itself, backwards running's been in warm-up programs in athletics or track and field programs since the beginning of time. We look at the Soviets and they were doing backwards running way back in the day. This isn't unique. They were using it as a way to specifically target the hamstrings and they were looking at a way to specifically target the quadriceps.

So you're getting high rate of force development from like a leg extension perspective, but you're also getting a high concentric action, high velocity, concentric action for the hamstrings. And it's just a way that's not trained. You can't really train it any other way.

James de Lacey5:12

If you're anything like me, you're short on time. Kids, family, work, training, and having to cook meals on top of that is just not going to happen. So I'm happy to announce Trifecta Nutrition are sponsoring the podcast. You get epic meals like these ones. Turkey taco bowl, Texas barbecue protein plate. These are a couple of my favorites.

But it means you don't have to prepare all your own meals and it makes getting in good nutrition relatively easy. I've tried other meal delivery companies. Most of them are too high fat, not enough carbohydrates, or if you're getting kits where you have to cook it yourself, the portions for two is actually for one, especially if you are like me and you're training often.

So, if you want to take something off your plate and have meals like this delivered to your door, go down the description. There's a link there where you can order trifecta meals. This is the performance line which are higher protein and higher carbohydrate and you can use code lift big 40. You'll get 40% off your first order.

Yeah, that's true. That's interesting. And I know Vern Gambetta has actually talked a bit about using backwards running exercises as part of warm-ups and training. What's interesting is he... So, what might be interesting as well is obviously you mentioned about track and field using it.

When people think of backwards running, they think of almost like it's almost like a shuffle backwards when if you're trying to do it fast, like if you watch American football, I remember Vern talking about how when he likes to do backwards running with warm-ups, he wants it to mirror what it looks like with forward running.

So, interesting to know kind of your take on are there certain ways you'd like people to do their backwards running? Maybe depending on the sport and things like that, are you trying to mirror the forward running motion or is this kind of like just move back as fast as possible or as efficiently as possible?

Aaron Uthoff5:12

Yeah, surely it's going to be context specific for the sport. But just like Gambetta, my PhD and the research that we do with it, we're trying to mimic forwards running. We're actually trying to get minimum ground contact time. We're trying to get a bit of hip extension. We're trying to have you be nice and tall.

And we want that because we actually want the foot to kick up and back. So you get that concentric knee flexion, but then you're also getting that concentric hip extension simultaneously. So we're putting the biceps femoris on a much higher concentric load in that shortened position to be able to train it and withstand the forces.

And again, we're talking about a shared central pattern generators, this circuitry. If we can replicate the movement going in both different directions, we're going to create a better pattern, a more consistent pattern that's going to translate to both directions. So, when it comes to specifically training it and the way that we use it to improve forward running speed or change of direction or things like that, we emulate it and you'll see that in a couple of the literature reviews that we've done.

The sports med, the new direction for training the backwards running one, and then the one in the strength and conditioning journal where it's kind of the practical applications and how you might coach it.

James de Lacey10:06

Okay, I need to find those papers. I don't think I've read those ones. I'll have to find them after this and go through them. And you mentioned obviously kind of like the replication and it's almost like a global input of the movement. It makes me think of kind of applications within combat sports. Then even though it's not backwards running, but maybe switching stances could be a similar concept.

So if you're an orthodox boxer doing shadow boxing in Southpaw, if same thing with maybe shadow wrestling, you have the left foot forward versus the right foot forward. Potentially that could be another application even though it's not maybe touching the same outputs in terms of backwards running when you're looking at more push off, etc. Do you think that there's some kind of crossover there?

Aaron Uthoff10:53

Yeah, absolutely. You think about if you're in a standing up situation, combat situation, whatever your discipline might be, and you need to be able to propel yourself backwards to gain space from your opponent, whether that's to get out of striking range or to set up maybe a lower body strike as opposed to an upper body strike. That initiation that you might do from just doing like a five meter backwards sprint as fast as you possibly can. That's going to give you that same adaptation to be able to create space rapidly, so you're training that same pattern.

James de Lacey11:30

Yeah. That's actually an interesting application. You don't, I guess you see it somewhat in certain maybe like closed kind of circuit cone drills and things like that in terms of like that backwards movement with the...

Do you think there is something there with even just switching to like your opposite side? So obviously you're just doing opposite movements. So orthodox boxer and then you're doing more southpaw shadow boxing. If there is some kind of, as you mentioned with the neural networks kind of being connected there, that becoming better at say southpaw shadow boxing will somehow transfer over to orthodox boxing, just as a very crude example, because of that kind of global network.

Aaron Uthoff12:16

Yeah, surely there's going to be some sort of transfer there and that's probably going to have some sort of unique adaptation from the way that the spinal engine working. We can think about oblique slings and things like that, the way that it works. And so if you can actually train that backwards running, you're actually training it kind of similar to you would with a strike.

Whereas if we're looking at like sprinting or things like that, the motion is actually in a reverse pattern. So if you're doing a backwards running, you actually end up doing the spinal engine works similarly as it would with a strike, like an upper body strike or even a lower body strike. So I think that there's be a lot of transfer over to it and that's an area that we haven't looked at yet, but would be really interested to know if anybody's out there doing it.

James de Lacey13:01

Yeah, that's very interesting. So in terms of application then, I'm assuming it's contextual to the sport but interesting just to hear maybe general guidelines like how are you implementing backwards running? I mean it's very general, but within like a training program in terms of maybe sets, reps, distances, anything that you kind of like to do or progression you like to have.

Aaron Uthoff13:25

Yeah. So basically the way that we look at it is I've started out with kind of lower intensity backwards running and then increasing the intensity and then modifying volume, basically undulate the volume as you go up. Like a step loading kind of progression with it.

And the reason I do that is because people are not that coordinated and yeah, if you [expletive] up going backwards, I've had a couple of people fall and break arms and things like that if they try to get to it too quick. So you want to make sure that they have the coordination to be able to perform the task effectively first.

So it might look like six reps of a 50% intensity backwards run. So basically 10 total reps across a session. And if you can think six at a low intensity, maybe three or two or three at a moderate intensity. So 70% to 80%, 90%, and then one or two maximum intensity, and then basically you just modify that.

So we're doing this over about 20 meters. We find that you pretty much tapped out maximum velocity about 12 to 17 meters with backwards running. So doing much more isn't going to really give you that much more of an adaptation.

So yeah, we're looking somewhere between 200 to 300 total yards or meters across a session. And then yeah, you just vary the intensity based on the training phase. Earlier in the phase, more kind of lower intensity. Later in that training phase, once they've adapted and they're used to the movement, let's go ahead and crank that intensity up and get some more high-speed meters in.

Oh, I was just thinking that another thing that you asked there is kind of, you asked about kind of set rep configuration, but we're also thinking about how many sessions in a week do you need? And this is something that we've been looking at quite a bit recently with this group out of Tunisia.

We're looking at one day versus two-day training. This is mostly with youth athletes, so we got to put this into context here. But what we're seeing is that the same volume split across two days tend to give you a better adaptation than a single day, at least for neuromuscular adaptations.

But when it comes from a metabolic adaptation or a physiological adaptation, what we're seeing is that it doesn't matter if you lump all of your volume in one day or split it across two.

James de Lacey15:13

I'm assuming that this backwards running is in addition to everything else that is going in the program, or is it replacing some of the other conditioning or running in the program? How does it usually fit within some of these scenarios?

Aaron Uthoff16:20

Yeah. So it is, the way that we've organized our studies is we're using their traditional warm-up as a control or their traditional training as a control. So we'll have a traditional training approach or warm-up approach. We'll have a forward running approach and then we'll have a backwards running. So we can look at the adaptations for the three different groups and then do a comparison for equivalent volume.

James de Lacey16:49

Okay, gotcha. And then you obviously mentioned with the adaptations from that you're seeing from this running. What kind of outcomes are you seeing from some of these backwards running interventions maybe compared to traditional warm-ups or forward running or anything else that's going on?

Aaron Uthoff17:06

Yeah. It's I guess an important thing to start teasing out there, isn't it? Shockingly, and it surprised the [expletive] out of me looking at it, is backwards running has been more effective than forwards running for improving vertical jump counter movement jump height, for improving forward running short acceleration. So up to 10 meter distances, times, and more beneficial than forwards running for repeated sprint ability.

So basically looking at, and it's not your fastest repeated sprint, it's actually the cumulative total repeated sprint across multiple trials, and we see that it's more stable across it.

So forwards running more effective than traditional sports training. Backwards running more effective than forwards running training. And we're talking moderate to very large effect sizes here, or for those of us that are more interested in a normal number, yeah, somewhere between like 10 to 25% improvements over forwards running.

James de Lacey18:22

Wow. How long are these interventions typically?

Aaron Uthoff18:22

Yeah. So we typically are looking between six and eight weeks. So yeah, that's a cycle or so.

James de Lacey18:35

What do you put the superior changes for backwards running down to? Would, maybe how much would you put it down to it being a novel stimulus versus maybe some of the structural physiological adaptations that you're looking to see?

Aaron Uthoff18:51

Yeah, that's a great question. I really wish that early on in this we would have had a look at time course for adaptations. And that's something that we're really going to try to tease out here moving into the future. Is this a neurological thing? Is it a neural stimulus that they're just improving that from a coordination perspective in the first week or two, or is it some sort of morphological or architectural adaptation to the neuromuscular system?

And I can't really tell you what that is because we haven't done the time course adaptations, but I can speculate that it's a little bit of both. I think that they're improving coordination and I think that's probably the primary adaptation.

I think that there is some neuromuscular adaptation from a high velocity kind of concentric approach to the hamstring. So I think we're actually changing muscle fascial architecture a bit, which is going to help translate to improved forward sprinting ability, as we know.

There's probably also a little bit of an adaptation when it comes to greater cross-sectional area of the plantar flexors, the tricep surae muscles, because of the slightly longer ground contact times and the double plantar flexion that we see in backwards running compared to forwards running.

James de Lacey20:15

Okay, that's super interesting. And then more speculation that you might not be able to answer, but how do you think that these, how do you think it, just in your opinion, if this was done long-term, say throughout an entire year or entire training camp, whatever it is, do you think that these that the superior nature of backwards running would still hold over maybe other interventions?

Or do you think it is worth keeping for long term to continue making improvements, maybe in addition or in replacement of something else?

Aaron Uthoff20:51

Yeah, I think that there's going to be a point of diminishing return, absolutely, just like any other training idea. If we're going to be doing squats, you can only do one type of squat for so long before you start to plateau. I think there will be a plateau with the adaptations that you see with backwards running, but I think that you can do it as a novel stimulus.

So if you're able to improve that coordination, I think if somebody hasn't done this particular task, if you are doing this over three to six months, you're going to see continued improvements. And that's what I see with my athletes. So I do it with, I train speed agility quickness drills for a bunch of different athletes and they are continuing to adapt and continuing to improve more with backwards running than forwards running over three to six months. But then you got to start throwing different things at them. So we're throwing like backwards power skips for height, backwards bounding, backwards different things.

And so you can modify the task around the basically training phase, right? So early off-season, okay, you can just kind of go for a little lower level and just do some normal backwards running, maybe some low-level skipping, some swaggers just to kind of get it. But as you're getting closer to the season, you can start looking at increasing whether it be impulse or whether it be velocity or whatever it is that your sport needs more of. Then yeah, modify the exercise to fit the demand.

But I would always keep it in your program in some way, shape, or form just to keep it fresh in their mind, just to keep that circuitry cool. And if that means that you're just doing like a backwards run to a forward run or you're doing circular runs or whatever it is just to improve that coordination, that's what we're seeing that is translating most onto the field, court, or arena.

James de Lacey21:51

I love that idea of backwards like power skips and backwards bounding. I didn't even think of that. I was like, that that makes so much sense to use. I really, I'm going to have to try that maybe on Saturday. I'm going to have to try that myself and try not to [expletive] it up. But you give it a go.

Aaron Uthoff23:05

You're going to [expletive] it up a few times, man. It takes a little while to get used to it.

James de Lacey23:11

You actually answered some of my question about overload because obviously you mentioned about at some point you're going to have to have some form of overload or increase the intensity of it to continue adaptations. I remember I can't remember who it was at AUT, M Farhan maybe, who did the backward eccentric, backwards, was it eccentric backwards walking that he did his PhD on? Tell me, have you played around with that at all or do you think there's any merit within this kind of framework?

Aaron Uthoff23:42

Yeah, absolutely. So what Fan did is he had basically, you were facing forward so it was looking like a normal resisted sprint, but this device was actually towing you backwards. So obviously a long time on the ground. We know that eccentric training is really good for increasing muscle fascicle length, increasing cross-sectional area of a muscle. So both those things can increase both force output and velocity.

So yeah, I played with that quite a bit. We're actually now working with an eccentric cycle. So we've just had another thing in-house at AUT where we're looking at using eccentric cycling and similar concept. So we got this wheelchair.

James de Lacey24:26

Yeah, Briggs' contraption there.

Aaron Uthoff24:26

So we've got this case study going on with a wheelchair sprinter and we're seeing ridiculous like three times improvement in standard, like three times the standard deviation in improvements in four weeks of using this device in sprint times. And so we know that there is something unique around that eccentric component to it. And I think that similarly what you're doing in like an unresisted sprint backwards, you're getting that eccentric loading at ground contact for the posterior chain kind of the opposite way that you would do for the anterior chain with forward sprinting.

So definitely, and we looked at actually loading up a sled. So I guess more from a concentric perspective, if you're towing sleds backwards as fast as you possibly can, it's still pretty effective. We don't see the, like, forwards running, forward sprint training, backward sprint training, pretty similar when it comes to forward sprinting ability. But when it comes to countermovement jump height, leg extension activity, we see that there's massive improvements and also improvements in stiffness. So if you need a fast short cycle, so you think in combat sports where you need to be poppy and be able to move quick.

James de Lacey25:57

Yeah, I love the eccentric cycle thing's awesome. I know I've talked to Matt for [expletive] ages on that as well because we have phone calls about it what, a year or two ago as well when we were in New Zealand and I think we ended up running into him at Millennium at some point too during that time. Again, we were doing the, my wife and I were hitting up to Millennium and on his little rigged up eccentric cycling device. He had one bike, two bikes facing each other.

Twice a week I was sprinting my balls off and then my wife was just resisting on the other side just to get basically to do a lot of body training because her back was pretty screwed leading into the Olympics. But like the eccentric stuff is so damn cool. Now, now it's he's got a motorized one, right? A motorized one that he's using up there that you can kind of sit on and a lot easier.

Aaron Uthoff26:44

Yeah, it's motorized. I'm doing a similar thing. So I've got it where I'm implementing it with yeah with my speed agility quickness training or my sprint athletes and yeah, it's really cool. The eccentric cycle is a phenomenal tool.

James de Lacey26:57

So how are you using the eccentric cycling then? Because what's interesting is when you default eccentric training, you go, "Oh, that's really intense. Like, I can't do this multiple times a week or I can't do it in the warm-up or cool-down whatever." But with eccentric cycling, it's almost like, like even my mother saying, it's almost felt like a recovery modality even though it's like repeated eccentric action. So it'll be interested to know how you're kind of using it.

Aaron Uthoff27:24

Yeah, so I'm using it in two different ways. So I'm using it first as kind of a thoracic mobility kind of spinal engine tool because if you're in a plank position, you can put your hands on it and it's going to work in a way that if you're keeping your hips stable, it's basically making a figure eight out of your T-spine.

And that figure eight out of the T-spine is going to translate to exactly what the spine is doing when you sprint. It's translating to what it's doing when you're striking. This is coming a lot from Angus Ross from High Performance for New Zealand, his ideas around it. And so I've taken that and applying it to my sprinters. And so I'm seeing that they're being able to utilize their spine in a whole body coordinative pattern more efficiently than just trying to focus on power from the lower body. So that's one application.

Then the other application I'm doing is I'm putting them in sprint-specific positions to either prime them before they're going to go out and, basically they do 10 to 20 seconds of eccentric cycling trying to resist it as hard as possible and then they go and they sprint. So just kind of the sprint-specific kind of way.

James de Lacey28:42

Would that be like almost like in a hurdle position with their feet against the pedals, not hurdle, a starting like a wall drill? Like a wall drill. Kind of 45 degree where they're standing on it and it's eccentrically acting on it?

Aaron Uthoff28:48

Yep. So basically just an inverse pattern of what the foot contact looks like during the acceleration phase. So yeah, that's been really cool. And then I'll use it post exercise for kind of more of a metabolic adaptation. So more time under tension depending on the phase of the season.

James de Lacey29:21

Do you remember, maybe just quickly explain for the listeners what this device actually looks like so they can visualize some of these things?

Aaron Uthoff29:28

Yeah, okay. So we've got a couple of different ways. So imagine a recumbent cycle. The ones where you're sitting down. You see your grandma grandpa sitting on it. You got kind of a geriatric population is really used to it. But instead of the cycles being propelled forward, they're actually being, it's propelled by a motor going in the reverse direction. So if we have that, we have a recumbent version and then let's assume now that we chop off the seat of that recumbent cycle and you're just left with the pedals of a bicycle. That's the version that I'm using with my athletes.

James de Lacey30:07

Yeah, perfect. Yeah, I remember Matt showed me a bunch of applications, some of the ones you mentioned there around that kind of plank position with the shoulders. I can't remember the other ones you had, but yeah, there was like a lot of upper body ones too. It's like it was super interesting just seeing the application of it and like that can be so useful in a sports performance setting. It needs to, it needs to go mainstream. Dude needs to release it.

No, absolutely.

Aaron Uthoff30:36

Yeah, do so, man, because we're commercializing it at the moment and the applications we're seeing are amazing. So it's increasing range of motion, internal external range of motion drastically, but what it's also doing is we're using it in baseball athletes as a warm-up strategy.

So got this idea of tips, which is how many throws it takes to get warmed up before you hit maximum velocity of throwing. And we're seeing that you can reduce your total number of throws necessary to be prepared to throw at maximum velocity way faster when using eccentric cycle.

So we're thinking about bullpen situations. We're thinking about between innings. We're thinking about things like that. So between an inning, you might have 10 to 20 minutes where you're just sitting around doing nothing that shoulder can cool down. So if you just hit a few seconds up to a minute of something where the eccentric cycle, that pitcher can get back on the mound and be ready to throw at maximum velocity again. Not that everybody is a fast pitcher, but it allows them to maximize the velocity in any pitch pattern that they're going to be throwing.

James de Lacey31:43

Interesting. Are you playing, I don't know if it has speed settings, but are you playing with any kind of different speeds on it?

Aaron Uthoff31:50

Yeah, so we've been playing with a few different things. So we've been playing with a 325, I think, no, it's a 375 watt and a 750 watt version. So obviously from a power perspective. And then we're playing with velocities, so RPMs. So some we're going down 30 RPMs, other ones we've gone up to 60 RPMs. And then we're also playing with crank length, so range of motion that you go through with it.

James de Lacey32:23

And it's still early days but it appears that the slower velocity tends to be giving better adaptations than high velocity for range of motion and a warm-up strategy. Just thinking practically just from having done some of it, I would assume that the faster velocity is just harder to maintain tension against maybe.

Aaron Uthoff32:50

It's a coordination thing really. That seems to be the thing that people have the hardest time with is just ability to activate their muscles at the right time to know when to resist it.

James de Lacey33:01

Yeah. I can imagine at the faster speeds it becomes even tougher because you're probably getting near the top then you're having to release and the other one and yeah, I can imagine it becomes more difficult.

Aaron Uthoff33:13

Yeah. But I'm a big fan of agonist antagonist co-contraction timing training. And so I think that there's a place for both speeds, a lower velocity and a higher velocity, depending on the level of athlete, what the specific adaptation it is, and what your training goal is.

James de Lacey33:36

Nice. Now, I love that we went down the eccentric cycling route because I needed to revisit it and reminded me I need to reach out to Brew Yelli again to chat more on it. But it'll be interesting to go into the other area of research as well. Maybe where things have potential, maybe new insights, things you're doing, new things you're doing or things you're still doing from before within the wearable resistance space.

Maybe start for the listeners with what the hell is even wearable resistance to start with. Because I think people when they think of resistance, just the traditional like 20 pound weighted vest or something.

Aaron Uthoff33:36

It's funny. Well, I love wearable resistance, man. I'm glad that we get to chat about this. And wearable resistance isn't new. Everybody knows what this is. It's just a matter of getting up to date that wearable resistance technology has changed over time.

We've all seen that lady walking down the road holding weights in her hands, speed walking. We've seen the ankle weights that have been used in the gym for ages. CrossFit has popularized the weighted vest again, right? So everybody looks like a tactical athlete nowadays. But these are all wearable resistance.

Now what's happened is there's new technologies like there's a brand from the US, omorpho, there is Leela from Malaysia and what they allow is they allow basically different loading patterns. So they have a whole suit basically so you have a global loading pattern, which means that you've got upper body loading where weight is distributed from your wrist all the way down to your ankle.

Or you have regional loading where you could wear just a vest or just a short or just a pant. And then you also have applications where you can do local loading patterns. So we can think of just on the calf or just on the forearm or just on the upper arm or just on the thigh.

And so now we've got these garments that you can either come with a specific weight or you can actually change the weights on and the pattern of the weight and all these different things to create a specific adaptation or a specific load depending on whether it's a technical adaptation you're looking for, whether it's a neuromuscular or physiological adaptation you're looking for.

James de Lacey36:16

Is that does that

Aaron Uthoff36:18

clear enough?

James de Lacey36:18

Yeah. Does that omorpho one, do they do what the Leela oxygen does with the individual loading or is that just like a weighted garment?

Aaron Uthoff36:18

It's a weighted garment. More so it's a little bit more comfortable and it does allow a slightly, it handles a little higher velocities better just because it's fully attached to you as opposed to some of the Leela stuff which can slide around depending on how much load you're using and which regional location you put it on.

James de Lacey36:18

So how are you using this at the moment with any of your athletes or within research?

Aaron Uthoff37:03

Yeah, let's talk research first and then we'll get an idea of where it's been used, its application, and then I'll talk to you a little bit around how I've been using it and how I've heard it being used as well for specific things.

So from a research perspective, we think about well first of all why would we use wearable resistance versus just doing normal resistance training. And the idea behind this is essentially the velocity specific overload. I don't want to geek out too hard, but I do kind of want physics behind it.

James de Lacey37:46

Go for my own just for my stuff selfishly. I'm sure people tend to enjoy the science stuff too on here. So hit it.

Aaron Uthoff37:56

All right. Cool. All right. So we need to start out with understanding the equation for kinetic energy. All right. So that's probably over some right now, but kinetic energy, the equation is one-half mass times velocity squared.

So what we see in this equation is that velocity, the squared part of that equation has a higher impact than what the mass does. So for an example if we move 100 kg back squat at 0.58 meters per second squared, what we get is basically 17.4 kilogram or meters per second. So our kinetic energy is 17.4 essentially.

Okay. If we move 1 kilogram at 6.1 meters per second squared we get 18.6 basically, kinetic energy is 18.6 kg per meters per second. Okay. So if you can move a lighter load at a higher velocity you're actually undergoing greater amount of work than the higher load at a lower velocity. Okay. So very basic there.

So we know that if you are putting this on the calf and you are moving at, top sprinters somewhere 9, 10, 11 plus meters per second squared while wearing wearable resistance, we're going to be getting astronomically greater loads on the hamstrings for eccentric, basically eccentric hamstring or knee flexion or knee extension. So we can target the muscles from that perspective.

So we've got the kinetic energy equation out of the way. That's fine. We got to realize that this is also linear. This is just a linear equation. And most of the things we do in the gym are all linear.

So what we need to then switch our mind to is that we move from this idea of vertical or linear loading to rotational loading. So rotational or angular kinetic energy, similar equation but now what we're getting is if you increase the circumference of a circle, so you think of like a leg rotation, you think of like a punch or an uppercut, roundhouse kick, things like that where you're starting to increase the radius of your movement.

Well, now we're starting to get even a greater adaptation that's just going to transfer based on velocity specific adaptations. Okay. So we'll go with that for now. I don't want to go

James de Lacey40:49

all we need to talk about with the angular, it's angular momentum is what is it? It's not mass times radius squared, is it? It's something else. Did I get that right? All wrong, I should say. It's half times the inertia with the angular velocity squared, I think that's

Aaron Uthoff41:11

that's for

James de Lacey41:11

kinetic energy, right?

Aaron Uthoff41:14

That's for kinetic energy. That's rotational or angular, yep.

James de Lacey41:22

Okay. Angular velocity. Okay. Yeah. No, carry on. Carry on. I'm just trying to connect things in my head while I talk out loud and sound like a dumbass over here, too. Carry on.

Aaron Uthoff41:34

No, no, no, now you're good. So it's half the inertia times the angular velocity squared. That's rotational kinetic energy essentially. And then the next thing what we're talking about here is rotational inertia. Okay, so inertia is mass times the radius squared.

James de Lacey41:55

There we go. That's the equation. I had it.

Aaron Uthoff41:56

There you go. You got it. Yeah, you got this. So essentially with wearable resistance is really cool because it gives you the ability to progressively overload without having to have more mass. Essentially I equals mass times the radius squared. Again, we're looking at mass is a singular metric and then the radius you square that.

So if you can think of like a limb. So you start at your bicep. Well your radius is relatively short from the insertion point and the proximal insertion point of the shoulder. If you move down to the wrist your radius of that becomes exponentially greater as it's squared. So you can simply overload the inertia of a movement by moving the load further down instead of having to just keep adding more and more and more mass which is what we have to do in the gym a lot of times.

So just grasping the kinetic energy perspective that if we can increase velocity the velocity component is more important and if we increase the radius or the distance from the proximal insertion of a body then that's going to lead to greater adaptation. So that's kind of the two ways that wearable resistance is beneficial.

Now when it comes to like what it's useful for essentially we can see that we get, we'll just talk about metabolic cost first and then we can kind of talk about some neuromuscular adaptations and some other stuff. So if you're wearing shorts what we found is if you wear shorts and for every 1% increase in body mass that you put for wearable resistance you get an increase of about 1.6% oxygen consumption. So 1% by what does that mean by

James de Lacey43:58

What does like 1.6 oxygen consumption mean and kind of like I don't know if there's like an analogy or something that could be used for that.

Aaron Uthoff44:08

What's the best way to explain what oxygen? It's just the more it's basically just the amount of oxygen required to complete a task.

James de Lacey44:18

Gotcha. And what would be like what would be like going for a walk or a jog or something like that? Is there like something that the activity could be compared to? I was trying to think just for easy visualization.

Aaron Uthoff44:30

Yeah, that's a great question. I'm trying to, all right. Well, I'll have to pull up the study from it because it's from a couple of the published studies that we've done on this from, oh what was it field, Alistister, his master's program but anyway.

So from the thigh it increases by 1.5% oxygen consumption for every 1% body mass you increase in thigh but when we move it down to the calf you get a 2.6% increase in oxygen consumption. So it just shows that if you move weight from a thigh to the calf, it follows along with this inertial that mass times the radius squared equation that you're going to increase the metabolic cost of this.

So essentially from a practitioner standpoint, stepping away from science and all this jargon and stuff, if you are looking to get the most bang for your buck and you actually want to increase the cardiopulmonary or cardiorespiratory adaptations from an athlete or basically load on them, you want to get more in less time. You can just use some calf loading and basically that's gonna put, well it's yeah about 8 to 12% more work required from the cardiorespiratory system versus no load at all.

James de Lacey46:06

So you could even as you mentioned you could add 1% of body mass of some wearable resistance to your calves. Say you're doing shadow boxing or shadow we call the shadow kickboxing or whatever and you're able to increase the metabolic cost of maybe your shadow boxing and you could also potentially use like weighted gloves that are maybe like, obviously you can get like 20 oz gloves or or whatever and that could also increase the metabolic cost of the upper body or you could just wear the wearable resistance up there too and the idea of that would then be now you're getting a stronger quote cardio stimulus from your shadow work. Correct.

Aaron Uthoff46:41

Yeah. Absolutely. Yeah, that's the way and that's kind of the way it's been used. And so we looking from a combat sport perspective. Let me pull this information up. So when we look at it, Dvetio and his colleagues a few years ago looked at using whole body loading with wearable resistance and they did basically shadow boxing. They did kind of some other training like they actually just wore it during a training session versus a group that didn't wear it during a training session.

And what we see is we get an increase of 26% jab impact power. We get a 51% increase in cross impact power. We're seeing a greater vertical jump. We're seeing greater five rep max bench press. And we're seeing greater five rep max half squats. So like it was is really impressive. But the biggest thing was compared to the control group, that jab impact power and that cross impact power were way more effective than just doing your training without it. So if you're looking power,

James de Lacey48:02

Was this like an intervention period? Was it that was like tested before and after?

Aaron Uthoff48:07

Six weeks. Yeah.

James de Lacey48:10

Nice. Yeah. Again, it makes sense just from physics in a sense with that. But carry on because you wanted to cover after the physical stuff, I think you wanted to cover some other adaptations with that or use cases.

Aaron Uthoff48:27

Yeah. Yeah. We can we can talk around some other things. So most of our research has really been in the the sprinting space. That's where the majority of this research has been both from an acute and a training perspective.

So what we end up seeing basically is that when you start using the forearms you start increasing basically propulsive impulse you increase step length you decrease step frequency and you increase flight time. So basically where you put this loading is going to change the stimulus or the acute response to it.

So from like a sprinting perspective, if we load the arms, we know that it's going to allow you to carry a little bit more time in the air. So, it overload step frequency. So, if you are having a hard time applying basically turning your legs over, you can wear this and then you're going to be able to improve your frequency when you take it off.

Alternatively, if you put it on the calf, what it does is it overloads contact time and stride length. So, if you are somebody who has a hard time putting power into the ground, then you can put it on the calf. So, these are different kind of use scenarios for, these are acute scenarios which we can transfer over into a training program and then see long-term adaptations.

James de Lacey48:27

Yeah, I love that. And I guess maybe more in a combat sports context, how maybe if could be speculative, could be something you've seen or done. How then are you looking to I guess to create this overload and potentially use this?

I mean, even within that paper, you're looking at I guess it probably depends on the on how well trained someone is. Because if you just slap it onto the calf for someone brand new, I mean, that's a [expletive] ton of torque and it's going to come through the hamstring and stuff when you're throwing kicks and whatnot. Is there some is there some progression that you like to use typically maybe within in combat sports or things you like to do?

Aaron Uthoff50:34

Yeah, so this is this is a really interesting thing that we found and it is contact specific and it is funny that you use that example for the kick. So, Seth Laneski and the crew from the, UFC Performance Institute in Shanghai, we did a review a few years ago on the effectiveness of different training methods for, impact power, for all different types of strikes.

And kind of two key takeaways here was that just kind of directly from the paper is that specific training methods such as banded strikes or wearable resistance appear to basically preferentially transfer to kicking performance. Performing combat training with wearable resistance leads to greater increases in punching performance.

So sorry. So banded strikes better for kicking, wearable resistance better for punching. Wearable resistance seems to be more beneficial for punches rather than kicks. The exact causes of this difference remain to be fully established.

However, what we speculated is that wearable resistance may cause an inappropriate over speed effect because of the greater inertia of the lower limb and then this may result in athletes applying breaking forces to maintain limb control during a kick.

Wearable resistance. Yeah. Right. So, so better for upper body strikes than lower body strikes likely because of some sort of probably a temporal disruption and that kind of increased breaking. So, more co-contraction with a kick than you would you would hope for.

James de Lacey52:09

You're almost you're almost trying to stop the the knee from like overextending because you have so much, not so much you have the load and the speed at the bottom end. So you're trying to stop that knee from singing so much that you're just like tense and you you can't quite get that effective mass to essentially transfer.

Aaron Uthoff52:24

Remember mass times radius squared, right? So radius squared if you do in a kick that radius moves way out and we're that velocity spins you around.

So we were doing a study with Red Bull a few years ago where we were looking at using it with basically their extreme sport athletes to increase centrifugal force so they can get more rotations. And what we were seeing is that when they were loading their arms and they were doing this, it was spinning the athletes so fast that they were actually not able to track where they were landing. So I think a similar effect is probably happening here.

James de Lacey53:05

Would you then recommend that if you were going to use wearable resistance for kicking, you would load it on the thigh somewhere or do you think that's even worth doing?

Aaron Uthoff53:16

Yeah, I would probably stick to your bands. I'd probably stick to a thigh. That would make sense. I definitely wouldn't be loading the calf for increasing lower body striking.

Again, you got to think about the pattern of it. Depend like if you're using like a teep for Muay Thai, that would probably be highly effective. If we're looking for like a tactical athlete or somebody who needs to kick in a door, then that's probably going to be a little bit more effective because we're not actually increasing the radius of it. It's more of a linear action. So just like with our upper body punches, we're seeing that there's more power can be improved. Well, it's likely because we don't punch with a crazy haymaker, right? At least professionals don't. So yeah.

James de Lacey54:09

So then would you be loading for the arm? You'll be loading basically as far down the arm as possible. So you're looking at kind of distal loading for punching as well.

Aaron Uthoff54:22

Yeah. So recommendations around that would be to start proximal. So start up kind of by the bicep and get used to it so you're not disrupting your natural pattern. You're still throwing the hand quick and it's more up there. And then you add a little bit of load so you start getting used to what it's like to have a little bit more mass around the shoulder. So you get a little bit of increase in strength, maybe a little bit more size of the shoulder.

And then you might lower it down across both the upper arm and the forearm, the proximal part of the forearm. And then once you start getting a feel of it, you progress that down further and further and further towards the wrist.

Another really important thing here is that there's different ways that you can load it. So with like the Leela gear, for example, it has this like fusiform. It's like a teardrop example. So it's got a fat end and then it's got a skinny end. And that means that there's going to be more mass at the fat end. Well, what you can actually do, and it depends on your striking style and things like that, but if you want, say the hand to roll over in a punch to get more maybe the first knuckle on a strike, what you can actually do is you can put the weight so there's more fat end on the inside and it's going to rotate the hand over faster.

So it's going to increase the velocity at which you can snap the wrist into position. Now that brings me to a really important point that this is from Joel Docherty who is the founder of Leela and it's you load to correct or you load to get the exercise in the pattern that you want to first. So for that example you load the fat into the inside so it snaps the hand into the position that you want it to be in if that's what you're looking for.

And then once the technique is exactly where you want then you swap it and you load to get the strength. So you load basically I want the hand to snap over but the fat ends on the other side. So it actually forces the musculature to rotate the wrist into that position.

James de Lacey56:25

No, I love that. And as you mentioned Joe Docherty there, if anyone's wants to listen to more of this, go back. It must be two years ago now. I interviewed Joe after this podcast. Listen to Joe Docherty and then you can listen to John Cronin as well. And you can listen to Angus Ross. I think all these three people he mentioned and Seth, you can listen to all of them on the podcast. So you guys got a ton of listening to do after this one too.

But that brings us to basically up to the hour. Aaron, what where can people find a follow and keep up with what you're doing? Or is there anything that I missed from wearable resistance first before going through all your socials?

Aaron Uthoff57:03

Oh man, I could talk about wearable resistance all day. We've done stuff in golf. So if you're looking to improve your golf swing, if you're looking to improve your strike, your club head speed, ball carry distance. If you're looking to improve your accuracy with it, let us know. Like I said, we're doing it in the extreme sports space. So if you're looking to improve that, hit me up. And then also always doing stuff in that combat space. So if you're interested, please reach out.

You can get me at email. So I'm at aaron.ut.ac.nz. So that's my email contact at the university. You can get me at Dr. Erin on Instagram and yeah, that's pretty much me.

James de Lacey57:52

I'll link this up in the description for anyone who's interested, too. But I appreciate you coming on and sharing that all. That was I thoroughly enjoyed going through all the some of the unique stuff and we'll chat again soon, I'm sure.

Aaron Uthoff58:05

Yeah, thanks James. Thanks for having me on, man. It's always good to catch up and hopefully your listeners got a little bit out of this and look forward to hearing from them.