Daniel E. Lieberman

Life is really just about, you know, food in, babies out, right? And the reason we eat food is for nutrients and calories, and calories is a unit of energy. So until recently, people struggled to get enough calories. It takes, you know, about 2,000 to 3,000 calories to run a human body for a given day. And if you're a farmer or a hunter-gatherer, getting those calories is not easy.

Life is really just about, you know, food in, babies out, right? And the reason we eat food is for nutrients and calories, and calories is a unit of energy. So until recently, people struggled to get enough calories. It takes, you know, about 2,000 to 3,000 calories to run a human body for a given day. And if you're a farmer or a hunter-gatherer, getting those calories is not easy.

Life is really just about, you know, food in, babies out, right? And the reason we eat food is for nutrients and calories, and calories is a unit of energy. So until recently, people struggled to get enough calories. It takes, you know, about 2,000 to 3,000 calories to run a human body for a given day. And if you're a farmer or a hunter-gatherer, getting those calories is not easy.

And you also have to pay for your children's caloric needs, their brains and all that sort of stuff. And so you're struggling to get enough calories. And so spending it on a treadmill to spend even more calories is a very odd modern thing.

And you also have to pay for your children's caloric needs, their brains and all that sort of stuff. And so you're struggling to get enough calories. And so spending it on a treadmill to spend even more calories is a very odd modern thing.

And you also have to pay for your children's caloric needs, their brains and all that sort of stuff. And so you're struggling to get enough calories. And so spending it on a treadmill to spend even more calories is a very odd modern thing.

Yeah, well, I mean, it's a paradox, right? We evolved to be physically active, and we have all kinds of mechanisms that reward it, right? So one of the reasons I exercise every day is that I'm addicted to it. I have a dopamine. Dopamine is the molecule of more. It's the chemical, the neurotransmitter which says, do it again, right?

Yeah, well, I mean, it's a paradox, right? We evolved to be physically active, and we have all kinds of mechanisms that reward it, right? So one of the reasons I exercise every day is that I'm addicted to it. I have a dopamine. Dopamine is the molecule of more. It's the chemical, the neurotransmitter which says, do it again, right?

Yeah, well, I mean, it's a paradox, right? We evolved to be physically active, and we have all kinds of mechanisms that reward it, right? So one of the reasons I exercise every day is that I'm addicted to it. I have a dopamine. Dopamine is the molecule of more. It's the chemical, the neurotransmitter which says, do it again, right?

And I have lots of dopamine receptors in my brain that are thirsty and hungry for more dopamine. And when I exercise, they get that dopamine hit. And if I don't exercise, they make me crabby and unpleasant. But the thing is, if you're unfit and or struggling with your weight, those dopamine receptors are going to be fewer in number and possibly even impaired in their function.

And I have lots of dopamine receptors in my brain that are thirsty and hungry for more dopamine. And when I exercise, they get that dopamine hit. And if I don't exercise, they make me crabby and unpleasant. But the thing is, if you're unfit and or struggling with your weight, those dopamine receptors are going to be fewer in number and possibly even impaired in their function.

And I have lots of dopamine receptors in my brain that are thirsty and hungry for more dopamine. And when I exercise, they get that dopamine hit. And if I don't exercise, they make me crabby and unpleasant. But the thing is, if you're unfit and or struggling with your weight, those dopamine receptors are going to be fewer in number and possibly even impaired in their function.

And so people who aren't already exercising a lot or being physically active

And so people who aren't already exercising a lot or being physically active

And so people who aren't already exercising a lot or being physically active

don't get the same reward so it's a it's a very strange mechanism and the reason that you might ask you know why why is that work the way it does is that in the past nobody ever was physically inactive that that just wasn't possible to you know to be active every day in order to hunt and gather or farm or whatever and so we never evolved to cope with um with a persistent physical inactivity

don't get the same reward so it's a it's a very strange mechanism and the reason that you might ask you know why why is that work the way it does is that in the past nobody ever was physically inactive that that just wasn't possible to you know to be active every day in order to hunt and gather or farm or whatever and so we never evolved to cope with um with a persistent physical inactivity

don't get the same reward so it's a it's a very strange mechanism and the reason that you might ask you know why why is that work the way it does is that in the past nobody ever was physically inactive that that just wasn't possible to you know to be active every day in order to hunt and gather or farm or whatever and so we never evolved to cope with um with a persistent physical inactivity

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.

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.