Daniel E. Lieberman

I was doing research in actually northern Mexico among the Tarahumara, who call themselves the Rarámuri. They're famous for long-distance running. They have these incredible races where they sometimes run 50, 60 miles. I was being a good anthropologist and I was going around and talking to folks and asking them about their running and And about their training.

And of course, the idea of training is when you run to prepare yourself for a race. And when I was asking all these folks about training, the word didn't even exist in their language. I was working through a translator. And so I was explaining, this guy here, the translator was explaining that I ran every day.

And of course, the idea of training is when you run to prepare yourself for a race. And when I was asking all these folks about training, the word didn't even exist in their language. I was working through a translator. And so I was explaining, this guy here, the translator was explaining that I ran every day.

And of course, the idea of training is when you run to prepare yourself for a race. And when I was asking all these folks about training, the word didn't even exist in their language. I was working through a translator. And so I was explaining, this guy here, the translator was explaining that I ran every day.

in order to get ready for races, and the guy looked at me, and I didn't even need a translator to figure this out, and he said, why would anybody run if they didn't have to? And for me, actually, that was the beginning of the book, because I suddenly had this realization that my exercise habits are really weird.

in order to get ready for races, and the guy looked at me, and I didn't even need a translator to figure this out, and he said, why would anybody run if they didn't have to? And for me, actually, that was the beginning of the book, because I suddenly had this realization that my exercise habits are really weird.

in order to get ready for races, and the guy looked at me, and I didn't even need a translator to figure this out, and he said, why would anybody run if they didn't have to? And for me, actually, that was the beginning of the book, because I suddenly had this realization that my exercise habits are really weird.

Well, it's not entirely true. So there's a very famous paper, one of my favorite papers, let me put it that way. There's a biologist in the Netherlands who puts mice on treadmills. And she noticed that she had mice in her backyard. And one day she thought, you know, what happens if I put a little running wheel in my backyard?

Well, it's not entirely true. So there's a very famous paper, one of my favorite papers, let me put it that way. There's a biologist in the Netherlands who puts mice on treadmills. And she noticed that she had mice in her backyard. And one day she thought, you know, what happens if I put a little running wheel in my backyard?

Well, it's not entirely true. So there's a very famous paper, one of my favorite papers, let me put it that way. There's a biologist in the Netherlands who puts mice on treadmills. And she noticed that she had mice in her backyard. And one day she thought, you know, what happens if I put a little running wheel in my backyard?

So she put a running wheel in her backyard and put some cameras on it, night cameras, went to bed. In the morning when she woke up, she looked at the camera feed and to her astonishment, wild mice in her backyard had gotten on this little running wheel and had run for a while. In fact, other animals had gotten on it too. I think a frog got on it and even a slug had gotten on the wheel.

So she put a running wheel in her backyard and put some cameras on it, night cameras, went to bed. In the morning when she woke up, she looked at the camera feed and to her astonishment, wild mice in her backyard had gotten on this little running wheel and had run for a while. In fact, other animals had gotten on it too. I think a frog got on it and even a slug had gotten on the wheel.

So she put a running wheel in her backyard and put some cameras on it, night cameras, went to bed. In the morning when she woke up, she looked at the camera feed and to her astonishment, wild mice in her backyard had gotten on this little running wheel and had run for a while. In fact, other animals had gotten on it too. I think a frog got on it and even a slug had gotten on the wheel.

So, you know, other animals do physical activity and why they do it

So, you know, other animals do physical activity and why they do it

So, you know, other animals do physical activity and why they do it

know well nobody knows right um and mice are really interesting because mice will naturally run you know several kilometers right they're a little bit unusual but uh it's certainly part of their behavior they're wired to do it but the vast majority of animals avoid unnecessary physical activity and humans are no exception except we now live in this very strange modern world where we've got elevators and shopping carts and

know well nobody knows right um and mice are really interesting because mice will naturally run you know several kilometers right they're a little bit unusual but uh it's certainly part of their behavior they're wired to do it but the vast majority of animals avoid unnecessary physical activity and humans are no exception except we now live in this very strange modern world where we've got elevators and shopping carts and

know well nobody knows right um and mice are really interesting because mice will naturally run you know several kilometers right they're a little bit unusual but uh it's certainly part of their behavior they're wired to do it but the vast majority of animals avoid unnecessary physical activity and humans are no exception except we now live in this very strange modern world where we've got elevators and shopping carts and

you know, electric can openers and you name it, right? And so basically now we don't really need to be physically active anymore, and yet our bodies require physical activity in order to turn on a whole variety of repair and maintenance mechanisms that keep us healthy. And so we've had to create in the modern industrial or post-industrial world this really weird behavior called exercise.