Daniel Priestley

And so physical activity actually helps promote strong and healthy joints. We used to think that it just caused them to wear away, but actually, you know, like cars, you know, wearing away at their tires. But now we know that actually physical activity promotes repair mechanisms in cartilage just as it does in other tissues in the body.

And of course, the other thing about running is that I think a lot of people run incorrectly today. So that's why we started studying barefoot running a few decades ago, is because if humans have been running for millions of years, most of that time we were running barefoot. So we're kind of curious, how did people run before shoes?

And of course, the other thing about running is that I think a lot of people run incorrectly today. So that's why we started studying barefoot running a few decades ago, is because if humans have been running for millions of years, most of that time we were running barefoot. So we're kind of curious, how did people run before shoes?

And what we learned was that today, shoes have these cushioned heels that enable you to essentially run the way you walk, right? You land on your heel. And everybody who's barefoot sometimes lands on their heel, but people who are barefoot often, more often than not, land on the ball of their foot and then let their heel down. It's called a forefoot strike or a midfoot strike.

And what we learned was that today, shoes have these cushioned heels that enable you to essentially run the way you walk, right? You land on your heel. And everybody who's barefoot sometimes lands on their heel, but people who are barefoot often, more often than not, land on the ball of their foot and then let their heel down. It's called a forefoot strike or a midfoot strike.

And when you do that, we worked out the biomechanics of that and published a paper on the cover of Nature showing that when you do that, you actually prevent your foot from crashing into the ground, causing what's called an impact peak, a collisional force. You run lightly and gently.

And when you do that, we worked out the biomechanics of that and published a paper on the cover of Nature showing that when you do that, you actually prevent your foot from crashing into the ground, causing what's called an impact peak, a collisional force. You run lightly and gently.

So if you were to take your shoes off and run up Lexington Avenue here, I guarantee you, you would not be landing on your heels. Within a few steps, you'd start landing on the ball of your foot because it hurts less. And so that's how we evolved to run. We evolved to run in a way that doesn't involve, you know, slamming into the ground with every step. And that causes less force around your knee.

So if you were to take your shoes off and run up Lexington Avenue here, I guarantee you, you would not be landing on your heels. Within a few steps, you'd start landing on the ball of your foot because it hurts less. And so that's how we evolved to run. We evolved to run in a way that doesn't involve, you know, slamming into the ground with every step. And that causes less force around your knee.

The trade-off though, because nothing comes for free, everything has trade-offs, is that it's harder on your ankles. Your calf muscles and your Achilles have to do now a lot more work to let your heel down. And so people who switch from heel striking to forefoot striking often have Achilles tendon problems. They get calf muscle problems. They don't do it properly.

The trade-off though, because nothing comes for free, everything has trade-offs, is that it's harder on your ankles. Your calf muscles and your Achilles have to do now a lot more work to let your heel down. And so people who switch from heel striking to forefoot striking often have Achilles tendon problems. They get calf muscle problems. They don't do it properly.

They'll get their foot muscles aren't strong enough. They'll get all kinds of foot problems. Right. So you can't just suddenly become a barefoot runner and start forefoot striking. If you're going to switch, you have to switch gradually and slowly and build up strength and learn to do it properly. Another thing people do is they tend to run like a ballerina high up on their toes.

They'll get their foot muscles aren't strong enough. They'll get all kinds of foot problems. Right. So you can't just suddenly become a barefoot runner and start forefoot striking. If you're going to switch, you have to switch gradually and slowly and build up strength and learn to do it properly. Another thing people do is they tend to run like a ballerina high up on their toes.

That's really hard on your ankles and your calves. So you've got to do it properly, but it can have enormous benefits. And we know, again, if you run that way, it puts much less force on your knees. And again, knees are where people get injured the most. So I think a lot of knee injuries come from the way in which we run.

That's really hard on your ankles and your calves. So you've got to do it properly, but it can have enormous benefits. And we know, again, if you run that way, it puts much less force on your knees. And again, knees are where people get injured the most. So I think a lot of knee injuries come from the way in which we run.

Well, I think what matters is how you run, not what's on your feet. So I would say a barefoot style. How do I learn to run in a new way, though? Well, I mean, there's some tricks. So one of them is, first of all, I don't know how you run. So maybe you already run just fine. But a barefoot style tends to be a high stride rate or high stride frequency.

Well, I think what matters is how you run, not what's on your feet. So I would say a barefoot style. How do I learn to run in a new way, though? Well, I mean, there's some tricks. So one of them is, first of all, I don't know how you run. So maybe you already run just fine. But a barefoot style tends to be a high stride rate or high stride frequency.

So 90 strides per minute or 180 steps per minute, roughly. 170 to 180 steps a minute is about right. Relatively short strides, so you're not throwing your leg out. And to me, the most important thing is not what we call overstriding. If you ask any coach on the planet, they'll say overstriding is bad.

So 90 strides per minute or 180 steps per minute, roughly. 170 to 180 steps a minute is about right. Relatively short strides, so you're not throwing your leg out. And to me, the most important thing is not what we call overstriding. If you ask any coach on the planet, they'll say overstriding is bad.

overstride is when you throw your leg out way in front of you and you land and that leg is a stiff leg so that a stiff leg means more force right um and uh and um and it's harder on your knees um and so if you and so a good runner lands uh with their with their shank with their tibia vertical so their ankle is below their knee when you do that pretty much everything will work out properly.