Welcome to the Movement Movement, the podcast for people who want the truth about having a healthy, happy, strong body. Remember, your body was meant to move. Now here's your host, Stephen Sashin. If you don't know physics, you shouldn't be buying running shoes.
I will tell you why, and I'm also going to teach you a little bit of physics enough to be really obnoxious at parties in just a few minutes here on this episode of the Movement Movement, the podcast for people who want to know the truth about what it takes to have a happy, healthy, strong body starting with the feet first because those things are your foundation. Here's where we break down the propaganda, the mythology, sometimes the outright lies that you've been told about what it takes to run, to walk, to dance, to do cross-fit, to do yoga, to power left, to do dance, to do dance revolution, whatever it is that you like to do and do that enjoyably, healthily and efficiently. I'm Stephen Sashin, your host for the Movement Movement podcast. You might notice this the second time ever I am not wearing a zero shoes dot com t-shirt.
I don't know, just one of those days. Really quick, if you like what you hear on today's episode or any of the previous episodes which you can find at www dot join the movement movement dot com then please make sure you subscribe, you like, you review, you share, ring the bell if you're on YouTube so you hear about upcoming episodes, you know all the things that you need to do. We call this the Movement Movement podcast because we're creating a movement about movement, natural movement to be more specific and because it is a movement that involves you so it's what you're doing that helps make movement move. If you have any questions or anything like that you can drop me an email at moveat, join the movement movement dot com and I think that kind of covers everything.
Oh, let me start with this. I always like to start with a movement and here's one that I'm not going to be able to demonstrate and you probably won't be able to do in real time but I want you to try it when you're at home and this couldn't be simpler. Let me tell you where it comes from. I had shoulder surgery a couple of years ago and I noticed that I was in a bit of a habit that to help make my shoulder work better.
I've been trying to change and that how it is, which way I put on my jacket. Normally I put on a jacket right arm first and then I reach around my back with my left arm to get that on so I've been doing it the other way around. I've been going left arm first and then reaching around my back to get that shoulder mobility to then get on my jacket. So I want you to try this when you get home, take things on and off with the opposite limb first.
We've done it before but I've done arms crossed and I don't remember which one I'm supposed to normally do first because I've gotten used to doing both. I switched back and forth. Some people can't do that so give that a shot but put on your clothes differently. Put on your pants with the other leg first.
Try your underwear with the other leg first but make sure you're not near as a set of stairs because that's the kind of thing that makes people trip and then do jackets. Do everything. Just try it upside down for a while and see what happens. This creates new neural pathways that can be really helpful for everything you might do because movement is all about what your brain is telling your body to do and if you give your brain new projects and new goals and new puzzles it's going to make you more neuroplastic which basically means that your brain gets better at learning new things or at least doesn't get worse at learning new things.
So give it a whirl. Let me know what happens if you really want to have fun type backwards and see what messages you send me by doing that. Back in the day when people used to write you could write with your other hand. That's a fun one too.
Anyway, the point is use your body the opposite of the way you don't leave it. Okay, so let's jump into your physics lesson of the day. I wish more people understood physics and I wish everyone understood it a little bit better. Not because I think that you need to know what I was looking for.
Know how to come on. I had a great phrase in my mind that it popped right out of my head. Know how to. All right, you fell in the blank.
Something a wave function. I've lost the verb and I'm looking for the blank a wave function. It's a super big deal physics thing about whether things are particles or waves and that's not the important part. The important part is physics is valuable.
Physics is the way that you can understand the world and when it comes to running shoes you need to understand physics because if you don't you will lose a bunch of money buying things that are not going to give you what you want that are outright complete marketing propaganda that might injure you. You need to know a little physics and it's not rocket science which is physics. This is something that doesn't require any math. It's just understanding a concept and here's the concept energy return.
Now when you understand what energy return is it will make you really obnoxious at parties because I have discovered that when you overhear somebody saying something that's just factually inaccurate and you go over to correct them and give them the new information because you think that would be interesting because I think that's interesting. You'll mostly find out that they think you were an obnoxious bore. So if you can handle being an obnoxious bore you're going to love what I'm about to tell you about this concept of energy return and even if you don't want to use this parties and have people think you're rude it's going to really help you find shoes that work for what your body wants to do which is bend and flex and move and feel. That's what all your body does and that's what your feet do as well.
If you don't let them bend and move and flex and feel that function of balancing agility and sending information to your brain about how to move your body correctly doesn't work properly and all those functions try to move unsuccessfully or they try unsuccessfully to move upstream your ankle, your knee, your hip, your back which aren't designed for that function that can cause a whole bunch of problems. So here's this idea of energy return. Running shoe companies make shoe companies have been using this concept for a while to tout the value of their phone or cushioning. The more energy return the better.
I mean doesn't that just make sense you want to get energy back right? Of course you do. The problem is there is no such thing as energy return. You never get more energy back from any cushioning or foam than you put into it and therefore what you really get is an energy deficit or more accurately energy suck.
So you are cushioning in your shoes. I don't care if it's air or foam or magic foam or springs or whatever it is. It doesn't return energy. It sucks energy.
Now you might say okay that's cool. Well don't I want the thing that sucks the least. I don't know because the problem is it's not so simple. All cushioning is basically tuned to a particular force a particular weight and speed or a particular mass and speed.
Well, technically mass acceleration. If you want to get into the physics force equals mass times acceleration. So foam is tuned to a particular mass. Let's call it weight, particular speed how fast you are hitting that foam.
And what I can tell you is the odds are good. You are not that mass or speed that the foam is tuned to. Now by the way, I've been talking about this for a while but I got really inspired to have this conversation when I saw an article from my friend Jeffrey Gray from Helux H E L U X E dot com. They are researchers in footwear.
Jeffrey does some really amazing stuff and he posted about this as well and inspired me to talk about it. And in the article that he recently posted at Helux dot com, he was talking about the Nike vapor fly 4% the Nike X% as well as an insole called victory VKT or Y. But frankly, the points that he makes in the ones I'm going to make, I'll have pretty much all shoes that have any sort of midsole cushioning of any kind. Again, airbags or foam or beads of whatever unicorn dust or I don't know what they put in.
So again, first things first, all foam loses energy. This is the point that Jeffrey makes on his site. We touched on that. All foam, all cushioning loses energy.
Carbon fiber is sort of the magic thing. This is the point that Jeffrey makes key point number two. Carbon fiber isn't typically used as an energy return material. The reason this is relevant is in the Nike next percent, the 4% etc.
They talk about the carbon fiber that they have in there as being part of why these shoes are so amazing. But carbon fiber is just a thing that's typically stiff and doesn't provide any energy return. In fact, if you think about it, imagine you have some foam, then underneath the foam you have carbon fiber. That's really no different than having foam and then underneath it, the ground.
So the carbon fiber is not really doing anything. Or let's say you have some carbon fiber or foam, then carbon fiber, then more foam. Well, it's again, not really doing anything in that case in terms of quote energy return, other than making the foam a little more stable. So maybe the foam sucks a little bit less or more accurately and more likely it makes it so the foam won't fall apart and break down quite as quickly.
A little iffy about that. There are some people who when they talk about the seemingly amazing performance of these new Nike shoes, they say, well, what the carbon fiber is doing is attacking like a lever. So it's like a spring that gives you extra energy. Well, once again, springs don't give you extra energy.
Springs suck energy. All cushioning sucks. I'm going to be saying that over and over because it's fun. Try it yourself.
You'll see. It's very enjoyable. So if you wanted to have a spring though, you can make that think about a diving board. That's a great spring.
And you actually do seem to get more energy out of it than you put in or trampoline, same idea, because you end up bouncing so much higher than you can jump. And it's not because that you're getting more energy out of it. You're actually putting energy in with your legs and your body, just the mass of your body, accelerating towards the ground. And you're using your legs, you're bending and unbending your legs.
So it's the force that you're using from your legs, your energy that works with this thing that has a fulcrum. It's a fixed point that something rotates around. And that's what makes you bounce higher off a diving board or off of a trampoline. Of course, you notice on a trampoline, you can't jump forever.
Your legs get tired because your legs are the thing providing the energy. It's just you match your legs with the trampoline or the diving board. And that's how you get that extra lift. By the way, if you watch divers, you'll see they adjust the fulcrum.
They change the flexibility of the diving board to match their body. Trampoline artists, you can kind of tune a trampoline as well, but you'll notice most of those guys and women, they kind of wave out the same amount. Trampolines are also tuned to a particular mass and acceleration, particular weight, particular speed, which again, you are probably not. So it's one of these things you look at all the runners in other ketchup chuggies sub to our marathon.
These are amazing runners. They're mostly African runners who weigh like 105 to 110 pounds running about 13, well, obviously running slightly over 13 miles an hour. If that's not you, then what they're wearing on their shoes or in their shoes just doesn't matter most likely because you are not a hundred and five hundred and ten pound Kenyan running 13 miles an hour, the Kenyan part completely irrelevant. But, you know, that's what they were.
So I said it that way. So there is no fulcrum anywhere in the Nike X percent shoes. In fact, it's really kind of funny. When you look at the cross section of that shoe, you'll see that the carbon fiber has a bent shape, but at the forefoot, it's totally almost totally flat.
And if you look at the video from ketchup chuggies sub to our run and I've got this posted on my website at zero shoes dot com slash blog, you'll see that they're all like mid foot and forefoot landing runners. So they're just landing on a totally flat thing that doesn't flex because it's carbon fiber. So where is the spring? Where is the lever?
The answer is nowhere. So that's not providing any energy return or any help the way people think of it as a spring or a lever or anything like that. Right. Here's a third point that Jeffrey brings up in his article.
Shoes with higher energy return on a mechanical ball drop test. Don't work for anyone or everyone. So the mechanical ball drop test is something that I don't know who made it famous. I think maybe Adidas made it famous when they came out with their boost phone a couple of years ago.
You may have seen this demonstration where they have two kinds of foam, quote, the regular foam that other shoe companies use and the boost foam that Adidas developed. And if you want to be, again, if you want to be obnoxious at parties when someone says Adidas, correct them and they go, it's actually Adidas because it's Adidas. The wrestler who started the company. So just so you know, and you have to give them that look too.
It's like, yeah, yeah, I mean, it's Adidas. Those of us who are really hip, we call it what it is. If we're really hip, we just call it Adi. So, you know, just so you know, anyway, they would bounce this like two pound steel ball on the regular foam and it would kind of just land there.
And then on their boost foam and it was really, really bouncy, which is really, really cool. Except for the fact that a ball of course never bounced higher than where it was dropped from, because again, energy sucked. And secondly, you are not a two pound steel ball. A steel ball is actually really, really elastic.
Now what that means in physics terms is not like a rubber band that stretches. Really elastic is kind of how much energy you get back from something when these two things interact. So a steel ball and a steel plate is very elastic because it's actually having a very small amount of energy sucked. So there's just not a lot of flex in the steel ball.
It doesn't squish. And therefore the energy of the ball hitting the ground goes right back into the ball, which sends it back into the air, which is showing that it's a more elastic interaction. Can't think of the word that I want for interaction to. And I still haven't thought of the word that I want at the beginning of blah, blah, the wave function.
It's a mathematical thing. It's going to drive me crazy. By the way, I'm about to be 58 and I'm losing words. If you are to tell me about it with all the words that you've lost.
So let's back up. Dropping a steel ball, the ball is dropping. That means it's accelerating towards the ground at 9.8 meters per second squared. Ignore that suffice it to say the higher it go, the higher you drop it from, the faster it is, the faster it's moving when it hits the phone.
They're only dropping it from a couple of feet, maybe even sometimes just a foot. And again, the ball weighs about two pounds. So the magic question is, what the hell does that have to do with you? And the answer is nothing.
In the same way, you are not a 105 pound Canyon running 13 miles an hour. You are not a steel ball dropping at 9.8 meters per second square, being a perfectly elastic thing. You are, let's say, a 150 pound runner who's coming towards the ground. You're definitely dropping from, you know, as you run your hips go up and down a little bit, maybe four inches, let's say.
So you're dropping from four inches higher than where you would be if you were standing. That's not a foot off the ground. You're not a perfectly elastic steel ball. Steel is not perfectly elastic either.
But you're not an elastic steel ball. You have things that bend and flex in your body. They're called muscles and ligaments and tendons. Your joints bend.
So you're not hitting the ground like a pogo stick or like wearing stilts. Whole different thing. So what a steel ball does, irrelevant. Secondly, here's a little bit of physics.
That foam that you're landing on just starts breaking down the moments and you start using it. So the ball results actually change over time. And this is something that people have studied where they keep doing the ball drop test or using something other than ball, something's like a piston. And they want to see how quickly the foam breaks down because shoe companies tell you that you're supposed to change your shoes every three to 500 miles.
Well, that's because that's when they've determined that the foam has broken down enough that it's not really helping you the way they think it should be helping you. By the way, it's not really helping you. But we'll talk about that in a second. More importantly, if you actually look at some of the studies on a lot of these foams, at the 300 mile mark, the foam is practically as bad as it's, well, is it the 500 mile mark?
And if you back up, you see the 200 mile mark, it's practically as bad as it was at the 300 mile mark. If you're at the 150 mile mark, it's barely better than at the 200 mile mark. So this foam is breaking down way faster than they sometimes like you to think. And the reason what the other thing they do is they build the outsole to rubber underneath the foam so that it starts to wear out around the same time the foam starts to wear out.
You know, the whole thing, they kind of fall apart at one time. Now, there's an endurance running coach named Phil Maffetone. I'm like totally on fire about this. I'm talking so fast.
Phil Maffetone, he used to say, go get the cheapest shoe. I think he still does. Actually, he wears your issues. But regardless, he used to say, go get the cheapest shoes you can get because when the foam breaks down, that's when they get good.
Of course, it used to be back then way back then when he first started saying this, that when the foam would break down, the rubber and the outsole was still usable, not so much the case anymore. So anyway, something to keep in mind. It's this little shoe secret that the foam is barely better after 150 miles or 200 miles than it is at three or 400 or 500 miles. Do with that what you will.
All right. Here's the fourth point that Jeffrey makes on his blog post about energy return. Foam with higher energy return can feel good to some people, which is wonderful because don't we all want to feel good. Of course we do.
That doesn't mean that it's good for you to feel good. I'm not saying it's bad for you to feel good. Feeling good is good. But it's not always optimal.
I ask you to drop into some pushups. Would you rather do that on the floor or on a memory foam mattress? Now, I'm betting that you said floor and I'm betting the reason you said that is that you are not an idiot and you know as much as a memory foam mattress feels good to lie on, it is not a thing you want to do pushups or squat jumps or anything like running on because it's too damn squishy. So this is Newton's third law of physics every action.
There's an equal and opposite reaction. On a floor, you're getting the best equal and opposite reaction back to the effort you're putting into it. On a memory foam mattress, it all gets squishy and all that you're getting an equal and opposite reaction, except it's not going back into your body efficiently. It's getting squished out in all these different directions thanks to the way the foam works.
Mattress feels good. Floor is better. Well, guess what? It's the same thing with running.
You get the best feedback when you're running on something really, really solid because that's telling your body if you're working correctly, if you're running correctly, if you're walking correctly, if you're moving correctly, if you rely on the foam and shoes, it's sending the force that's going into the ground and then back from the ground and all these different directions which can cause a whole bunch of problems. This is why when you see people who are running barefoot, you can usually spot them from a block or so away because they're often doing this crazy thing called smiling. It's when I teach people about how to run barefoot, I go find a nice smooth hard surface because you want the most feedback possible and the best quote energy return, which actually is not energy return because the energy is all just coming from you. They're not losing extra energy into foam that's between you and the ground.
But you want that feedback. You want your body to move as effectively and as efficiently as possible and it doesn't need anything in the way to mitigate that. So that's my physics lesson about energy return. What does this mean for you in practical terms though?
It's when you go to a shoe store, if you still go to shoe stores to buy shoes and they start talking about the energy return, you can just shake your head and say, you know, I'm just not a 105 pound Kenyan guy running 13 miles an hour. What else you got or you can find shoes that don't have this issue because they're not trying to put things into the product that don't really mesh with the laws of physics. So zero shoes, we don't have mid soles with a bunch of foam. Most of our shoes and sounds are just a layer of rubber.
Sometimes we do add a tiny bit of foam that definitely sucks a tiny, tiny bit of energy but also registers as surprisingly comfortable. In fact, it's something that we're confused by like, we're like, oh, so here in the teraflex or hold that thought way up here in our new Mesa Trail trail running shoe, there's about a two to three millimeter layer of foam hiding on the inside of the soul and it only compresses a tiny, tiny little bit. It shouldn't be as comfortable feeling as it is. And I have a theory about this that maybe we'll talk about in another podcast episode about evolutionary biology and that is that tiny bit of cushioning feels good because way back in the past, that feeling probably told us something good was nearby like food or water because there's no reason that that tiny little bit of cushioning that we have in the Mesa Trail soul or in our Z trail sandal soul feels as good as it does.
So we can talk about that later. Maybe you have a theory about why that's the case also. So all that said, I hope this little lesson on physics gives you something to ponder something to think about, something to be obnoxious to your friends about at parties and maybe inspires you to take a gander some other things that you ignored in high school for me. It was history that could actually help you become a better consumer and more importantly, a happier, healthier human being as you go about your moving life, walking, dancing, running, hiking, kayaking unit.
In fact, there's things that apply to kayaking in your tube. That's a whole other story. Anyway, I hope you enjoyed or got something valuable out of this episode of movement movement podcast. Please once again, pass it on.
If you like what you heard, subscribe and like and review and share and give a thumbs up and hit the bell on YouTube. The simplest thing I can say is if you want to be part of the tribe, please subscribe. And the tribe is the people who like the idea of making natural movement the obvious better healthy choice the way natural food is. So maybe at some point everybody in the world will be able to do all those activities running, walking, hiking, pain-free, enjoyingly until they're in their 70s and 80s and 90s and well beyond.
Once again, if you have any questions or comments, you can leave them in all the various places, you can leave questions or comments. You can also drop me an email at moveatjointhemovementmovement.com. I think that's all I've got. So once again, thanks so much.
Live life-free first. Have fun. You've been listening to the Movement Movement podcast with host Stephen Sashan. Remember to join the tribe and subscribe at jointhemovementmovement.com.