A lot of people exercise because they

believe it will help them to lose fat.

One of the biggest debates on the

planet. What advice have you got for me?

So, this is not a well-known fact, but

Daniel Lieberman, he studies and teaches

how humans are supposed to live.

Author and professor at Harvard

University

exercise

disease sleep, nutrition

He has the answers on all of those

things that most of us care about.

We evolved to be very physically active,

working in the fields, hunting,

gathering, but now we live in a world

where

only 50% of Americans ever exercise. And

the rest of the world is headed our way.

cancers depression, anxiety can

attribute that to less physical

activity.

In fact, women who get 150 minutes of

physical activity a week have a 30 to

50% lower breast cancer risks.

And it's crazy, right? Problem is that

we spend 3% of our medical budget on

prevention. And yet 75% of the time the

disease is a preventable disease. It's a

completely backward, stupid system. When

you started writing this book about

exercise, was there any instant changes

that you implemented into your own life?

strength training The more I study the

importance of doing weights, especially

as you age, the more I started kicking

myself for being lazy about that. When

people retire, they become less active.

They tend to lose muscle, and then that

starts off a vicious cycle.

So, would you say we shouldn't retire?

Well, it's a very modern Western

concept, and yes, we do pay a price for

it. So, how does one go from having a

negative opinion towards exercise to

becoming an exerciser? As an

evolutionary biologist, there are

multiple ways of doing that. So,

Daniel,

what are some of the biggest myths

within exercise? Gosh, there are so

many. One of the most common, of course,

is

Daniel Lieberman, he's been to every

corner of the world visiting native

tribes to understand how humans are

supposed to live. And now he has the

answers on all of those things that most

of us care about on sleep, nutrition,

exercise, disease. You know, on disease,

he says that 74% of them can be

prevented. And he knows how to prevent

them. Aging, running, are we born to

run? He tells me this story of a CEO

that forces his employees to exercise

and the impact that that's had on that

company. And he talks about how as

humans, we've evolved to either use it

or lose it.

So, maybe maybe retirement is a really

bad idea for many of us.

One of the most thought-provoking,

pivotal conversations I've had on the

show. You're really going to take a lot

from this one.

And I suspect after listening you'll

probably start running, too.

For exercise or from some of the

decisions you've spent your life making.

Daniel, your work is so so incredibly

impressive

reaches such an incredible depth

charters new territory

and it's been

an unbelievable

clearly very passion-driven career you

had. So, my first question for you is,

why are you doing this?

Um

it's a good question. Um I am you know,

I started off being obsessed by human

evolution. I ever since I was a kid, I

was really interested in human

evolution, and for I spent much of my

early career working on skulls and heads

and why they are the way they are.

And then I kind of got involved in

public health and issues of health and

disease kind of through the back door. I

sort of slowly shifted my research

trajectory towards studying the

evolution of running and then the

evolution of physical activity

and its relationship to health and

disease, and and I've become part of a

movement that's often known as

evolutionary medicine, which is how to

apply evolutionary theory and data to

issues of health and disease.

Evolutionary medicine, I've never heard

that term before, but I love it.

Where has your

work on evolutionary medicine, let's

call it, where has that taken you? Where

where has it taken you to learn, to

research, to study?

You know, so much of what we think about

in terms of health and disease comes

from a tiny fragment of the world's

population. Almost entirely, like 90% of

all the medical information comes from

people from the United States

Canada

Europe and Australia. So, in order to to

study how bodies really work and how our

bodies evolved to be you have to leave

uh places like Boston, where I live and

go to places like Africa or Mexico or

wherever to look at at at other

populations and look at how those

populations are transitioning to to

lifestyles like mine. And so, uh we've

been working in Kenya um

for the last 15 years or so, um and I've

traveled some other parts of the world

as well, India you know, to kind of

collect some data, but uh but mostly in

mostly in Africa. After doing all of

this work and after taking in all of

this information, how has it shifted

your perspective on

running, exercise more broadly? What

Have there been any sort of significant

cognitive perception changes, you know,

Yeah, um

I actually had a I mean, it doesn't

happen very often, but I had kind of an

epiphany moment um

when I was working in Mexico. We were

collecting data on the Tarahumara, very

also famous for their long-distance

running.

And uh there was this elderly guy, he's

about 70-something years old, and he's

famous for his distance running, and I

was asking him how he trained, and I had

asked this question of a whole bunch of

other people, and the translator I was

working with was always struggling to

ask that question, because it turns out

there's no word for training in in that

language. The concept of training

doesn't exist. So,

so so she was trying to explain to this

guy what my question was. Um and I could

even with a translator, I could figure

out just from his tone of voice, he was

like, why would anybody run if you

didn't have to?

And I suddenly realized, yeah, of

course, exercise

is a very weird thing, right? If you're

if you're a farmer and you're working

super hard every day in the fields

without machines and whatever, or if

you're a hunter-gatherer and you're

walking, you know, you know, 5 to 10

miles a day and digging and throwing,

you know, doing all kinds of hard work,

and you're barely getting enough enough

food

why on earth would you go for a needless

5-mile run in the morning? I mean, it's

crazy, right?

The most viewed videos of yours

and the most viewed moments in those

videos

address one question. Do you Do you have

any idea what it might be?

No, actually. The biggest myths in

exercise.

Right. And I think you actually pointed

out one there with the um insight you

got in Mexico.

The way we exercise, going to gyms,

practicing, is the natural or human, but

evidently it's

it's a consequence of the privilege of

our lives and the comfort we have of not

having to seek out our our dinner every

day. What are some of the other biggest

um myths with within exercise that um

you've come across in writing this book?

Gosh, there are so many. I had to

actually limit limit it to 10. So, I

think um if you want to understand

physical activity and exercise, you also

have to understand inactivity. And I

think one of the biggest myths out there

is that you need 8 hours of sleep a

night. Um and that sitting is the new

smoking, you know, that that basically

And I if you if you think about those

two different myths

uh why is it that we're constantly told

to sleep more and to sit less?

Actually, it's kind of seems a little

contradictory to me, right? And it turns

out that um uh that let's take sitting

first. So, um

you know, there are all these uh you

know, these slogans like sitting is the

new smoking, and it's really bad for

you, and you know, every time you sit in

your chair, you lose 2 hours of your

life, and you whatever. Uh turns out

that um all animals sit, right? My dog

sits, um cows sit, chickens sit, every

animal sits. And hunter-gatherers also

sit. In fact, if you uh some of my

students actually put sensors on

hunter-gatherers, and uh when when we're

doing some research in farmers as well.

But they sit just as much as Westerners.

Um

uh so, sitting is there's nothing

special about being uh about today's

life. It's sitting It's It's that we sit

all day long and don't do anything when

we're not sitting, right? So, if you uh

and furthermore, the the big distance

difference is not so much how much we

sit, but how how we sit. So, turns out

that people who um

if you get up every once in a while,

right? Interrupted sitting is actually

much more healthy than non-interrupted

sitting

for the same amount of time. So, in

other words, two people might In in the

West, people sit for an average about 40

minutes at a at about. Whereas

hunter-gatherers, for example, or

farmers in Africa, where we work get up

every about 10, 15 minutes. And when you

do that, you actually it's like turning

on the engine of your car. You don't

even drive it around the block. You're

you're you're you're um you're turning

on all kinds of cellular mechanisms. You

lower blood sugar levels. You You all

kinds of genes get activated. And it

turns out that that is by far the most

important um uh way to way to sit. So,

just get up every once in a while. Just

pee frequently, make a cup of tea, you

know, pet your dog. Whatever. Thinking

when I'm on planes and I've got a long

flight, I just I always sit in the

aisle, right? So, I can get up a lot.

Always. Ah.

And um What about sleep, then? So, sleep

is another interesting one. So, this

idea that, you know, um that you need 8

hours of sleep

has been around for a long time. It's

been around basically since the

Industrial Revolution. Um but um if you

actually So, so, colleagues in my field,

so in evolutionary medicine, have put

sensors on people who don't have

have all the things that we're told have

destroyed sleep. it. We're told that TV

and lights and and uh you know, our

phones and all these things are are

preventing us from sleeping, you know,

Edison destroyed sleep, right? Uh so,

so, when you put sensors on people who

don't have any electricity, they don't

have TVs, and they don't have phones,

and they don't have have have any of

these gadgetry, right? Electric They

turns out they sleep like 6 to 7 hours a

night. Um and um they uh they don't nap.

Um so, this idea that natural human

beings sleep 8 hours a night is just is

just nonsense. It's just not true. And

furthermore, when you start looking at

the data 7 hours, if you actually look

at if you graph sort of how many hours a

night you sleep on the x-axis and sort

of uh you know, some outcome like

cardiovascular disease or just how how

likely you are to die

it's kind of a U-shaped curve. So,

people who don't get much sleep are are

in trouble.

Um but the bottom of that curve is

pretty much always about 7 hours.

So, people actually do better if they

sleep 7 hours rather than 8 hours. And

yet we're told that if you don't sleep 8

hours, there's something wrong, right?

Oh, so you can oversleep.

Well, yeah. I mean there's also some

complexity to this, too, because of

course people who are ill might be

sleeping more. And so there's some

there's some biases that creep into the

how you analyze the data. But but

basically it turns out that seven is for

most people optimal, but there's a lot

of variation, right? Never You know,

teenagers sleep more, older people sleep

less. It's complicated. One of the

things that

popular in culture as well as this idea

of doing 10,000 steps a day. Yeah, now

that's fun. You know, that started

because of a Japanese pedometer

pedometer. Um so but right before the

the Olympics were in Tokyo in the in the

'60s, uh they had invented the pedometer

and they were in sitting in a boardroom

and they were discussing what to call

the pedometer and they picked out of

just out of the blue they picked 10,000

steps because that's apparently an

auspicious number.

And it sounded about right. There was no

science behind it.

Interestingly, it turns out it's pretty

good. Um if you actually if you look at

at steps per day

and health outcomes,

um your average hunter-gatherer um

walks between 10 to 18,000 steps.

Depends on male, female, etc.

And and if you look at steps per day and

and outcomes, um um

at around 7 to 8,000 steps the curve

kind of bottoms out, right? There's

doesn't seem to be a huge advantage to

taking more than that per day in terms

of you know, large epidemiological

studies. So,

turns out to be not that bad a goal, but

it's not a there's no

it's not a perfect number like a lot of

things, right? It's just a kind of a

it's a reasonable it's a reasonable goal

to shoot for.

When you um

when you started writing this this book

about exercise and running and all these

subject matters, was there any

instant changes or any real lasting

changes that you implemented into your

own life from everything you'd learned?

I I think about that all the time with

this podcast. I'll have a guest on. I

have these many eureka and then

something will stick. So I'm I'm

wondering having studied all all of

these people all around the world and

looked at their bodies and exercise and

physical exertion,

what have you taken into your own life

that has stuck?

I would say that I've become more

serious about doing some strength

training. You know, I've I've always

loved

walking and running and you know,

endurance kinds of activities and I've

always sort of hated doing weights, you

know. I just don't like it. And I'm I'm

I'm I'm a wimp, you know. I'm not a very

well I'm I'm not a very strong person.

And you know, people tend to do what

they like, right? You get reinforcement

from it. And uh the more I study the

importance of resistance training and

the more I study the importance of doing

weights, especially as you age,

um the more I've uh

the more I I started kicking myself for

for being a being lazy about that. So

now I try to do a good two strength

workouts out of every week at least. And

uh

and take it more seriously because

especially as you age,

loss of muscle mass can be really

debilitating. There's a

um the technical term for that is

sarcopenia. Sarco is is the Greek word

for muscle and penia is loss, so muscle

loss. So as people get older, they tend

to lose muscle and when you do that, you

become frail and you lose functional

capacity and then that starts off a

vicious cycle, right? Once that happens,

then you're less likely to be physically

active and then of course when you're

less physically active, your muscles

begin to waste away more and uh it's

very debilitating. So I think as we get

older and I'm getting older, it's more

and more important, you know, to to kind

of incorporate that. So I think that's

the one thing that I've I've taken to

heart. Yeah, from what you said there,

it sounds like

not doing resistance training, not doing

not lifting weights as you age almost

accelerates aging and in any sort of

superficial sense, but but it also in a

physiological sense, you're

you're increasing the speed of aging.

Yeah, I'm not sure if I'd think about it

that way, but it I think I I kind of

reverse it slightly, which is that

you know, aging is just

the clock ticking on, right? There's

nothing we can do about age, but

senescence is the way the way our bodies

degrade as we get older.

And what physical activity does, perhaps

maybe the most important thing about

physical activity,

is that it slows senescence, especially

for certain organs and systems. And

there are different kinds of physical

activities. So there's endurance

physical activities, you know, like

running, walking, etc., swimming. And

then strength or resistance physical

activities and they have different kinds

of ways in which they slow various

properties of senescence, which we, you

know, colloquially call aging. And all

of them are important. And I think one

of the things that's really interesting

about humans, in fact, I think it may be

the most important thing about this book

and you asked about myths earlier. The

most important myth, I think, by far, is

this idea that as you get older, it's

normal to be less active. And that is

just not true. Um we evolved to be

grandparents. We evolved to live with

one thing that's most interesting about

humans, maybe, is that we evolved to

live about 20 years or so after we stop

reproducing. No other animal does that

except except orcas, maybe killer

whales. But with the exception of killer

whales, humans have this really weird

life history. We we we evolved to be

grandparents. But grandparents in the

old days weren't, you know,

retiring to Florida or I don't know what

they what they do in England or

whatever, go to Mallorca or whatever and

you know, kick up their heels and play

golf or whatever with carts.

Grandparents in the in the olden days,

right? Or in in many cultures still

today, are working, right? They're

working in the fields, they're hunting,

they're gathering, they're getting food

for their children and their

grandchildren, they're helping with

child care. And that physical activity

is, you know, that's what their job is,

to be physically active. But in turn,

that physical activity turns on an

amazing suite of of of physiological

processes that counter aging. Turns on

repair and maintenance processes that

not only keep our muscles strong, but

also keep our DNA from accruing

mutations, keep our mitochondria numbers

high, keep um keep our the cells in our

brain from accumulating gunk uh so that

prevents Alzheimer's and other forms of

dementia. I mean, for almost for every

system of the body, physical activity

has has benefits that slow the aging

process. And so when you stop doing it,

you accelerate and that's the way in

which you it

you perceive it as accelerating aging.

But really it's the absence of physical

activity, which lets aging run amok. In

your first book in 2013, The Story of

the Human Body,

in chapter 12 you said um

you used this phrase, you use it or lose

it, basically. We we evolved to use or

lose our bodies. And I was sat with um

someone recently and I was trying to

figure out why it appears that when

people retire or the other instance I've

seen is when their their elderly partner

passes away, it appears as if they don't

live much longer. Yeah, it's kind of

like kind of folklore or something that

once you retire,

your days are kind of numbered. Yeah.

Yeah. And I I was trying to figure out

the evolutionary reason for that, but it

sounds like that's kind of what you've

explained there. Well, I mean, I think

part of that is um is is depression,

right? Um

um when you lose a partner, I mean,

grief and depression, your cortisol

levels go up, your immune system goes

down. I mean, you know, it's it's it's

really tough on your body.

I mean, psychosocial stress plays a

serious physiological toll.

But but also, as you just pointed out,

when people retire, they become less

active. And that that loss of activity

has enormous effects on every aspect of

our our our of our of our body. I mean,

and our brain and our minds. I mean,

physical activity is important not just

for physical health, but also vital for

mental health. And um I think a lot of

the problems that uh a lot of mental

health issues we have today, depression,

anxiety, uh

some of them, you know, to some extent,

uh we can attribute that to loss to less

physical activity. And as people age,

becoming less physically active, again,

makes them much more vulnerable to a

wide suite of diseases.

So would you say we shouldn't retire?

Well, or if you do retire, I mean,

retiring is a again, another modern

weird thing, right? Nobody retired in

the past. I mean, if you're a farmer,

it's like a subsistence farmer in name

it, any place, right? It's not like

suddenly you hit 65 and all of a sudden,

you no longer have to work in the

fields. You work in the fields until

you're, you know, until you're dead,

right? And hunter-gatherers don't

retire. They they continue to be

physically active until until they die,

right? Or until they get too sick. So

it's a very modern Western concept um

and um and yes, we do pay a price for

it. But you of course can replace,

you know, work that you do with with

with challenging, rewarding, fun things

to do. The important thing is just not

to not to stop being physically active.

One of my favorite studies ever

published, without a doubt, um is is a

is a study done by a guy named Ralph

Paffenbarger. He realized that uh places

like Harvard are fantastic for studying

aging

because um Harvard, like other private

universities, never lets go of their

alumni.

So, until you the day you die, they're

asking you for money on a regular basis.

And and so they're um um

and so he he got the alumni association,

the Harvard Development Office, to let

him follow a series of Harvard alumni

from several years and keep asking them

in questions about their physical

activity levels and also their diet and

whether they smoked and stuff like that.

And then he tracked them for 25, 30

years.

And what he found was that the alumni,

we after corrected for every factor you

could think of,

that as you as the alumni got older, the

effect of physical activity on their

health outcomes was bigger and bigger.

So, alumni who were in their 20s, 30s,

and 40s, for example, who were were

exercising four, five times a week, they

had about 20% lower death rates.

By the time they they got to their 60s

and 70s, the alumni who were exercising

more had 50% lower death rates. So as

you get older,

so what and this has been replicated

again many times, but what he showed was

that as you get older, exercise becomes

more, not less, important for

maintaining your health.

Been thinking a lot about this cuz I was

I was saying to Jack, my dad is 60-ish,

but he's very, very out of shape. Very,

very out of shape. And I was in um I was

in Indonesia and I was with my

girlfriend and we went and we were going

white water water rafting. So, we had to

go down this really big hill.

And with all these stairs, it was like

300 m of stairs. And I remember of just

thinking, my my dad wouldn't be able to

do this at his age at 60. And I want to

be able to go down those stairs when I'm

his age because at the bottom of there

was a fun activity with someone I loved.

And to think that I'll get to a point in

my life where

not so far away in the grand scheme of

things um where I won't be able to go up

or down some stairs because I'm 60

um because of my sort of genetic

predisposition as I saw it was quite was

quite sad. But having heard you say

that, it's really feels much more like a

choice than it is genetics. Yeah, well,

we have this expression in my field,

which is that genes load the gun and

environment pulls the trigger, right?

Some of us have genetic predispositions

towards being, you know, more likely to

get diabetes or heart disease or this or

that or the other. But

our great, great, great grandparents

in different environments weren't

getting these diseases or they were

getting them at much, much, much lower

frequencies. It's not because they were

dying earlier. It's because these

diseases were more less common. So

I think we too often blame our genes for

uh many of these these these diseases um

or many of these health problems. Um and

it's I'm not in any way denying the role

of genetics is but that environment is

way more important and we have control

over our environment to some extent. And

so if you want to reduce your risk of

cardiovascular disease, reduce your risk

of diabetes, reduce your risk of

Alzheimer's, dementia

you you exercise isn't a magic bullet.

It's not going to prevent you from

getting those diseases completely, but

it lowers your risk

uh quite, quite, quite substantially.

And we know why, too. I mean, we have an

immense amount of data on why that's the

case. Um uh for every single one of

these diseases, we understand the

mechanisms by which physical activity

has uh you know, important mechanistic

effects on on these diseases. So, it's

there's epidemiological data, there's

mechanistic data, there's personal data.

The problem is that it's hard to do,

right? It's it takes willpower to um

overcome the the the the inertia of of

of of doing what's completely normal,

which is wanting to take it easy, right?

I was I was just, you know, I just flew

yesterday from Denver to Boston.

And in the and the in the in the airport

you know, there are these escalators

right next to the stairway, right? Mhm.

And and and and um the escalator and the

stair it wasn't a huge stair.

Everybody's lining up to take the

escalator. And like the stairs are

totally free. So, I

being me, I of course I can't I'm not

allowed to take the escalator unless,

you know, I have to, right? So, I I ran

up the stairs, but you know, it's but

those people taking the escalators,

nothing wrong with them. There's they're

not lazy. It's just an instinct, right?

It's an instinct to take to take it easy

when you can, right? Because when and we

now live in a world where everybody can

do that, right? Because we have

escalators and and lifts and cars and

shopping carts and all these wonderful

devices

to make our lives easier. And now you

have to overcome this fundamental basic

instinct to take it easy in order to be

physically active. And that's basically

what exercise is.

And so

and and furthermore, if you're out of if

you're unfit and you're not really, you

know, exercising isn't any fun, right?

It's it's it's it's unpleasant. You, you

know, you sweat, you get hot, and you

get cranky, and you know, um and and

it's not that rewarding

uh until you get fit. And so uh people

hate it, right? Um and and then we blame

them for being lazy. But they're

actually just being

they're just being normal. And I think

we need to have more compassion towards

towards people who struggle to exercise.

Quick one before we get back to this

episode, just give me 30 seconds of your

time.

Two things I wanted to say. The first

thing is a huge thank you for listening

and tuning into the show week after

week. Means the world to all of us and

this really is a dream that we

absolutely never had and couldn't have

imagined getting to this place.

But secondly, it's a dream where we feel

like we're only just getting started.

And if you enjoy what we do here, please

join the 24% of people who watch this

channel regularly and have hit that

subscribe button.

Means more than I can say. And if you

hit that subscribe button, here's a

promise I'm going to make to you. I'm

going to do everything in my power to

make this show as good as I can now and

into the future. We're going to deliver

the guests that you want me to speak to

and we're going to continue to keep

doing all of the things you love about

this show.

Thank you. Thank you so much. Back to

the episode. This basic instinct to take

it easy

are we evolved to be lazy take escalator

riders? Well, I wouldn't use the word

lazy, but we are evolved to take it

easy, to to rest whenever possible,

right? So, we've now got ourselves into

a bit of a comfort crisis here because

everything has in our lives is

optimizing us for convenience and ease.

Right, right. And well, it's also it's

it sells, right? I mean, comfort I mean

I mean, who prefers to sit in economy as

opposed to business class, right?

Nobody, right? Comfort's nice, right?

Who prefers shoes that are

uncomfortable, right? We we we, you

know, comfort's

comfort's, you know, we we love comfort,

right? But since when is comfort

necessarily better for you, right? I

mean, are comfortable shoes actually

better for you than going barefoot or

the comfortable chair is better for you

than or taking the the lift better for

you than taking the stairs?

the short term or at least it appears to

be today. Right. Yes, because we often

value the short-term benefit over the

long-term cost, right? Um that's, you

know, hyperbolic discounting is the

technical term for that. But but um so

we, you know, we live in a world where

where we we we, you know, we pay extra

for for comfort or we and we'll we'll

prefer it. But um but now we also live

in a world where we have to now go out

of our way to be physically active

because it's no longer necessary. And so

again, I'll go back to my original

statement, which is that people evolved

to be physically active for two reasons

and two reasons only. When it's

necessary or rewarding. When we don't

make it necessary, we need to figure out

ways to make it rewarding. And and

that's hard. It's very hard.

Making it rewarding. So, one way that

you might make something rewarding is by

looking at the stick. And then the other

side is maybe the carrot. But just

looking at the stick then, you were

going through a series of diseases a

second ago, Alzheimer's, um high blood

pressure, all of these kinds of things,

cardiovascular diseases. I almost think

we've come to

assume that these are inevitabilities of

life. Yeah. We'll get cancer. Yeah. One

of us will get Yeah. Someone in here is

going to get Alzheimer's. And that's the

way we live. So, we're we're we're

preparing to medicate when that day

comes.

That's right. I get God forbid diagnosed

with something. That's absolutely right.

In fact, that's what medical students

today are taught, right? If you go to

medical school today

you're taught that as people get older,

their blood pressure goes up. I can tell

you that's just not true. It's in the

Western world where people are

physically inactive and eat crap diets

that their blood pressure tends to go

up. But there are plenty of people

I'm actually one of them, right? Who

don't have high blood pressure as they

age. And guess

what's the best way to prevent getting

high blood pressure as you age? It's um

you know, I sound like a broken record,

but we have this idea that as you get

older, yes, you're going to you're and

we're lucky, right? You know, because we

don't die from smallpox when we're 30.

We're lucky to get cancer when we're 60,

right? What we've done is we've confused

diseases that are more common with aging

with age being a cause of those diseases

in the first place. And they're not

inevitable inevitable diseases. Um and

many of them are preventable. And and

the problem is that in our society we

we don't value prevention very much. We

we may talk about it, but we don't

really put our money where our mouth is,

right? In the US, which is arguably one

of the worst health care systems is the

worst health care system among the

industrialized Western world.

We spend approximately

3% of our budget our medical budget on

prevention. And yet when people walk

into a doctor's office, 75% of the time

the disease is according to the Center

for Disease Control a preventable

disease. So, we essentially spend

nothing to prevent diseases that

overwhelm our system and cause enormous

amounts of misery. It's a completely

backward, stupid system. And so and and

the good news is it's not that hard to

prevent a lot of these things. Um um it

takes willpower and um takes education

and it takes access to to good quality

food and whatever. Um but um uh so in in

one sense, it's very depressing. On the

other hand, the optimist in me says, you

know, we really can do something. And

people even if without even if they're

not wealthy or whatever, I mean, there

are simple things that everybody can do

to improve their health outcomes.

These diseases we we encounter today as

we age and just generally in our

society, when you look at

hunter-gatherer hunter-gatherer

communities or you look at certain

tribes around the world, maybe in Africa

do you see the same

um

the same types of diseases in the same

um

occurrence level of occurrence? Or is

there some diseases which just don't

like I'm wondering if like if cuz you

know, cancer seems to be so popular for

as as disease and Alzheimer's and these

kinds of things. So, I wonder, has that

always been the case throughout human

history? And is that the case in other

parts of the world? Uh such a good

question. So, first of all, some of

these some of these diseases are really

hard to to measure in non-Western

populations because we don't have the

diagnostic tools. So, nobody really

knows how common cancer is in in in a

lot of parts of the world, right?

There's just no the data don't exist.

That said, when you make estimates and

you do look at the studies that are out

there and even if you look in in in

historical records in in places like

Europe where people have been keeping

track of this, there's no question that

cancer rates have been rising and that

cancer rates are much, much more common

in the Western world. There's a strong

association between cancer and wealth.

And that's because cancer is basically a

disease of energy, right? When your

cells cuz cancer is basically natural

selection gone awry in the body. It's

when cells start competing with each

other

um in ways that that cause it basically

and and start, you know, going, you

know, multiplying and dividing out of

control, right? It's a kind of natural

selection. And what is it that those

cells are doing? They're competing for

energy. And when you have more energy

like when you're eating more and being

less physically active

you can you basically feed those cells.

So,

um so cancer so a high levels of insulin

insulin is highly

uh related to to cancer. High insulin

levels are are carcinogenic. Um high

levels of of body of of energy you cause

women for example to increase the the

amount of estrogen and progesterone that

they produce. Men produce more

testosterone. These are and these are

these are

hormones that um of course are for good

for reproduction, but they're but again,

we have we evolved to be to have as many

babies as possible, right? But that

doesn't mean that translates into

health, right? So, more estrogen, more

progesterone increases risks of say

breast cancer. More testosterone

increases the risk of prostate cancer.

So, if you look at most diseases, right?

People are more physically active, they

have lower levels of estrogen,

progesterone, testosterone. They have

lower levels of insulin. They have lower

levels of blood sugar. All of these

depress cancer rates. And on average,

people who are physically active have

much lower rates of almost every single

kind of cancer that you can think of.

Women who walk 150, you know, get 150

minutes of physical activity a week

have on average

about 30 to 50% lower lifetime breast

cancer risks than people who are

sedentary.

And yet for some reason, this is not a

well-known fact.

Um and we under we have we have

epidemiological data. We have

mechanistic data. We understand how and

why it works. And yet and yet how often

do you hear about cancer prevention? We

talk about treating cancer, which is all

important. If I get cancer, I would like

it treated, too. Thank you very much.

But why don't we spend more energy and

activity and and and have more education

about how to prevent cancers in the

first place?

Physical act I mean I've never had that

before. So, that's that's really helped

me um

to add more value to exercise in my

mind. You're talking there about insulin

levels and how that has there's

a link between your insulin levels and

your chances of getting cancer.

Sugar.

Glucose.

Inflammation.

Bad.

Yeah, I mean I mean look, if you want to

you want to take like the three things

you should, you know, if you really care

about your health, don't smoke, right?

That's kind of obvious. I think

everybody knows that.

Get some exercise. I don't think you

need me to tell you that, right? And and

cut down on sugar and foods that are

high in sugar and low in fiber, right?

That you know, what we call high

glycemic foods. Those are the foods that

elevate your your your your blood

glucose levels. Your your insulin levels

shoot up. And insulin insulin, the basic

function of insulin is is is it's it's

what we call an anab- anabolic hormone.

It's its job is to is to store energy.

Glucose.

Glucose, but also fat. Okay. All right.

Okay. So, ins- ins- what insulin does is

to get energy into cells. So, it's like

a taxi.

It's like an Uber. It's like a taxi,

yeah. Well, I mean it it's not a tac-

it's like a it's telling other cells to

do that. So, insulin for example binds

to other cells that are the actual

taxis. So, it's like it's like calling

the Uber, I would say maybe, right? Um

and um and insulin is is, you know, it's

the funda- So, when you when you eat

food, insulin levels go up because its

job is to store that energy. And when

you exercise, insulin levels go down

because because you want to then use

that energy, right? So

so uh so

when cells get more energy, they're more

prone to going out of control,

basically. And and and and inflammation

is caused by

basically by getting you store so much

fat in your cells that those fat cells

start to swell. And when those start to

swell, like anything, right? They start

to rupture. They get damaged. And that

damage attracts the immune system and

the immune system gets turned on and

that causes inflammation. So, so too

much adiposity, too much fat, you know,

overswollen fat cells

is the is a primary cause of systemic

inflammation. And inflammation is like

the slow burn in our bodies that causes

widespread damage to pretty much

everything you can think of. And it

turns out that So, the two ways to deal

with inflammation are one to prevent it,

right? So, don't eat foods that are

pro-inflammatory.

Like?

Anything with a lot of sugar, basically,

right? That I mean that you know, the

sugar is highly inflammatory.

Um or trans fats are highly

inflammatory.

But also, turns out many people don't

know this, but you also want to turn

down your immune system, right? You want

to turn the dial down. And

I don't know, I'll just give you one

guess what it is that does that.

Exercise. Exercise. And the and and and

the way it does that is that when you

when you're physically active, you're

using your muscle cells. It turns out

muscles are also an endocrine organ.

Your muscles are producing a molecule

called interleukin-6, IL-6 that in low

levels is pro-inflammatory, but at high

levels, it's actually anti-inflammatory.

It turns down inflammation. And your

muscles because a third of your body is

muscle, right? When you go for a run or

or swim or bike ride or whatever you're

producing a ton of this stuff and it

turns down levels of inflammation. So,

people who are physically active, even

if they're overweight are actually

controlling and regulating their

inflammation. And we never evolved to

regulate inflammation because in this

way because we never evolved to be

physically inactive. Until recently,

nobody was physically inactive until

they unless they were dying, right? So,

so we never evolved an alternative

mechanism to regulate inflammation other

than physical activity.

And we didn't live in a world with this

much sugar. We never lived in a I mean,

it's astonishing. You you pay more money

for foods today that have less sugar

added.

Right? I mean, that's just ridiculous,

right? Cuz it's so cheap. And sugar is

you know, we love everybody loves sugar.

I mean, I've um I've gone hunting with

um hunter-gatherers, you know, you know,

foraging hunter-gatherers.

And um

and I can tell you that they're honey

addicts, right? I mean, I've gone out

with these guys and they go from

you know, if if they if they fail in

their hunt like by 10 or 11, if you

haven't killed an animal, you know,

that's it for the day, right? And then

it come it turns from being a hunting

expedition to a

honey collecting expedition. And they'll

go from hive to hive to hive

get smoke, burn out the bees

and just gorge themselves on more honey

than I could possibly imagine to eat.

Except these are lean

physically active hunter-gatherers and

they they handle it just fine. Um

but it's you know, it's the it's the

Paleolithic equivalent of, you know,

eating Mars bars all day long.

But they've been out doing physical

activity for how long? Yeah, I mean, the

average day is about 15 km of of walking

with some running, you know. So, so so

they're you know, they can they can they

can cope with it. How many hours is

that?

Oh, that's two to three hours, probably.

Okay, so from that I have garnered that

I need to do 15 km a day

for two to three hours every day.

Well, remember, it's not a prescription,

right? So, that's that kind of like the

paleo fantasy sort of naturalistic

fantasy that if you live like a

hunter-gatherer, somehow your your your

world will be perfect, right?

That's basically what the paleo diet is

sort of all about, right? And that's not

true, either.

Yes, you need to be physically active,

but it turns out that a certain amount

you know, if you're any any physical

activity is better than none, right? And

if you look at the kind of any curve of

any output, any health health health

health outcome like

how many years you live or whether

you're likely to get cancer or heart

disease or whatever, you know, any

little physical activity, your curve

starts to fall quickly, right? Your your

likelihood of cardiovascular disease

starts Just, you know, a few minutes a

day of exercise has big benefits. But

eventually that curve flattens out,

right? And it flattens out well before

the hunter-gatherer level. So, you don't

need to be a hunter-gatherer in terms of

physical activity to get the benefits.

This is a I've asked a few people this

question. I don't think everyone's

anyone's really answered it. Um but I

suspect you might be able to. If if you

were responsible for redesigning the

nature

of our modern world to make it more

matched and less mismatched

what are some of the first things you

would do to help society benefit in

terms of our happiness and our health?

I I think about this all the time. I

think cuz we we we don't seem to be

turning around. We seem to be hurtling

in a direction kind of unconsciously

towards artificial intelligence and

moving less and being more sed-

sedentary and taking pills more to fix

everything.

Lonelier than ever before.

And I got you know, if we were to

redesign it, blank canvas

piece of paper

It's a tough question because

um

we've essentially given

ourselves what we want.

Right? Um I can go into a supermarket

and

I mean, I can do something that's

unimaginable until recently. I can have

I can I can have basically anything I I

can eat better than the king of France,

you know, a few generations ago. I can I

I can I mean, here we're I can New York

I there's like every cuisine possibly

available to me. I I don't ever have to

climb the stairs. I can take elevators.

I mean, we've we've we've we've made our

world

so convenient and comfortable

um and yet there are consequences to the

many of the things that we crave and

want.

So

in a ideal world, you don't want to

you don't want to

rem- I mean, you have to you have to

honor

and respect people's

um um desires, right? I'm not a I I

don't believe in in in preventing people

from taking the elevator, right? Or or

forcing them to you know eat eat whole

grain bread as opposed to white bread,

right?

But if you banned white bread and you

banned elevators other than for those

people that need it for accessibility

reasons, etc.

They would do better. Over the long

term, they would be healthier and

happier. They would. Right. So, the it's

really a a balancing act between between

um

um respecting people's liberties and

choices and educating them and helping

them. So, in my world, I would I would

do more to nudge people, right? Um I

would instead of banning sugar, I would

tax it more.

Um instead of um

uh

pushing

uh all kinds of foods on people, I would

push I mean, why don't we why don't we

advertise

healthy foods the way we advertise

unhealthy foods, right? I mean, when's

the last time you saw an ad for just how

amazingly healthy asparagus was, right?

But that doesn't get the part of my

brain

going, does it? No, it doesn't, but um

but we could do more to to nudge and

encourage and help people, right? You

don't have to like ban sugar and

cookies, right? Uh the way some people

but but but simply promote um and help

people

help themselves, right? Most people want

to eat healthier food. Most people want

to exercise. Um but they live in a world

where it's hard to do it and they live

in a world where um there are very few

incentives. I would make it such that

healthy food would be as as inexpensive

as as unhealthy food.

And make sure that that people had

incentives and and make it also fun to

be physically active. Like for example,

um

every I mean, who doesn't like to dance,

right? Every culture in the world has

dancing, right? Dancing is a form of of

of physical activity.

It's social, it's fun, it's engaging.

Why don't we have uh have Why doesn't

every every town in America sponsor

dancing?

Right?

Um you know, it would probably do an

enormous amount for people's physical

health and their mental health. I mean,

we could do that I mean, that's just one

example, right? So, I would I would um I

would I would I would and and why is it

that uh in medical schools doctors don't

learn about I mean, they don't they

don't study nutrition and they don't

don't study exercise and they don't

learn um because that's because in our

medical system is designed to treat

people after they get sick rather than

prevent people from getting sick. So, so

we need to we you know, reverse how we

fund health care, right? And so, schools

of public health are these kind of

little marginalized places where you

know, where where great ideas go to die,

right? And and medical schools where all

the money is, right? And doctors aren't

taught to to deal to to to I mean, there

are entire fields of medicine that don't

have the word preventive associated with

them. I mean, have you ever heard of

preventive orthodontics or preventive

you know, optometry or preventive you

know, the preventive orthopedics. I

mean, it just doesn't exist, right? So,

we we could do a lot more um and and

have enormous benefits. Chapter 11 of

this book, you talk about someone who

has taken their own approach to getting

people moving and exercising

um in their own business. That was the

Björn Borg company. I love that. Björn

Borg company. Can you tell me about that

that company? Yeah, so I was um

so I was I was curious about this idea

of how to get how to help people be more

physically active, right? And again,

you know, my my fundamental hypothesis

is that we evolved to be physically

active either when it's necessary or

rewarding.

And so, I was curious if there was any

any companies in the world that have

made physical activity necessary. In

other words, what if we force people to

be physically active? And I found one so

far. I think there's only one company in

the world that I know of. Maybe there's

some others, but this is the only one

I've ever found so far. And it's the

Björn Borg sports company in Sweden

where the CEO of the company is this

crazy sort of exercise addict and he um

he requires every member of the company

to to exercise. They have sports hour

every Friday at 11:00 o'clock.

So, I actually um when I when I was like

searching around and I was thinking, you

know, I like working on the book, I

actually, you know, I got I I thought I

found a an article about them and I, you

know, I clicked on the on the company

website.

And you know how most companies have a

little contact us? Mhm. So, I I clicked

on the contact us and I wrote a little

note saying, you know, "Dear Björn Borg

company, I'm a I'm a researcher and

evolutionary biologist. I'm interested

in exercise and I'm and I'm fascinated

by how your company um requires people

to exercise. Can I learn more?"

And the next morning, there was a an

email from the CEO of the company

saying, "Why don't you come and visit

us?" So,

so I hopped on a plane uh a few a few

months later, went to Sweden and they

they let me He was so nice. He just let

me just go anywhere in the company. And

I I went to sports hour and I I talked

to to employees throughout the company

and it was fascinating. I mean, um a lot

of the employees of the company

um first of all, a bunch of people

apparently left the company when he took

over as CEO and required this. But it

doesn't matter who you are. You could be

working in the mail room, you could be

the CEO, you could be on a visiting

board member. Whoever you are, if you're

there on Friday, you have to go exercise

with them. And they have this pretty

serious kind of exercise thing. And

apparently, some people quit. Um but um

but but pretty much everybody else said,

"You know, it's actually a pretty damn

good thing." Do you agree with that

approach? Well, yes and no. Um every

university in the world used to require

and every school, right? Supposedly

requires exercise, right? I'm sure you

had physical exercise you know, physical

some kind of phys ed required in your

school.

Those standards are slipping around the

world and more and more kids are doing

less and less in school.

Uh universities were are no exception.

It used to be that all universities

required some degree of physical

education. Uh mine was no exception. In

fact, Harvard was a leader in that back

in the, you know, 100 something years

ago.

And over the uh since basically the

1970s, that's basically disappeared.

Although most students, if you ask them,

they think, "Yeah, it's actually a

pretty good idea."

So, I don't know. Maybe we can bring

back exercise as a And and the thing is

that if you get used to it, right? When

you're young, you're more likely to

do it when you're older, right? Cuz you

set Those are the that's the age in

which your habits become

become

well, your habits become your habits,

right? And so, at there's a certain age

where where if you can keep keep

get that making it make it a habit,

you're probably more likely to continue

doing it for the rest of your life. We

kind of see it as overreaching, don't

we? I was thinking about if I was to

announce one of my companies that

everyone is now required to exercise, it

would seem like like tremendous

overreach. If I announced that everyone

is required to read a certain book,

they'd do it and it'd be fine. And it

might be seen as a positive thing,

right? Might be a representation of our

values that we are learners and we're

innovators and we keep, you know,

nourishing our brains. But if you turned

around to your team and said, "Listen,

we're all required to you're all

required to go for a run every day or

something." People would it just feels

personal. Like that's not the

responsibility of an organization to

tell me

to go

exercise.

But we have we have company, you know,

retreats. I mean, we do all kinds of

stuff where people are required to do

it. So, I don't know. I challenge you.

Try it. What we do and what we've always

done, we even do it with this team. The

Drive CEO team is about 30 people. So,

we have a fitness channel in the company

um Slack channel, the communication

channel that we use.

And in that channel um and we did this

at my previous company as well where we

would

enable and facilitate. So, we we

someone started a women's football team.

So, we enabled it and promoted it.

Someone started a men's football team,

so we enabled it and promoted it. And

this this also applies to non-physical

sort of exercise related clubs like

someone starts a reading club and we

enabled it and promoted it. Um and we

also paid for it. If they need to if

they need new kits, for example, when

the women's football team needed wanted

to have their own uniforms, we paid for

it because we saw a huge value in terms

of staff retention, connection,

community and all those things that

actually lead up to staff retention

if we could have more social clubs

outside of the office. You know, if

you're thinking about leaving a job,

there's a number of things you weigh up,

the pay, the job, whatever. But you also

weigh up how the community, like the

group of people I love and how much they

bring to my life. And I actually think

in the remote working world, um it's

something that CEOs and leaders have

really not paid enough attention to that

if they really want to retain their team

members, they should have them together

as much as they can even outside of the

office bonding in a world where screens

are on the rise and pubs are on the

decline and social activities and

churches are on the decline, there's

less sort of

uh institutions that connect us

socially, work has a big opportunity to

do to do that. So, one of my big things

that's always in my head is like how can

I get the team members of my companies

to hang out more and and a multiplier to

that is how can I get them to hang out

more and move their bodies more cuz then

they'll feel better. Right. Well, well,

think about it. It's play, Play, yeah,

exactly. And I mean, and play is what is

another thing we evolved to do, right?

What kids play and we're one of the few

species that plays as adults, right? And

what is play? Play is a way in which you

you you learn cooperation, you you you

build community, um but you also move

your body, right?

In the first chapter of your book, you

say that you went to visit the Native

American tribe and I'm going to try and

perhaps pronounce this, the Tarahumara.

Tarahumara. And they're famous for their

long running. Yes. What did you learn

about running from them?

Well, it's you know, they have been

famous for well over 100 years. I mean,

many uh people have gone to study the

Tarahumara and and have commented on

their amazing ability to run.

But what I I really learned from them is

that um uh for them, physical activity

is spiritual. Um

you know, there's this book Born to Run

that uh that describes their their

running and

calls them a hidden tribe of super super

athletes. They're not hidden and they're

not super athletes. Um and um and the

one thing that the book missed was that

the the main impetus for the for the for

the running they do these famous

long-distance races is that it's a form

of prayer.

Um it's really very beautiful. Um and um

and it's it's a metaphor for for life

and and and it's also an an opportunity

to bet and sports and all that. It's all

wrapped into one.

And and what I've learned was that this

actually used to be

almost universal among Native American

populations, right? Native American

tribes. Everybody had long-distance

races and ball games and and all they

were all had a spiritual element. It's

just that

they've they've retained their

traditions because they're in a very

remote

part of of Mexico that's essentially

inaccessible. We all used to do this.

All uh humans used to do this. And in

fact, if you think it if you look around

the world, every population has this

tradition of endurance endurance events.

Some of the subject matter you talk

about in your book, but also outside of

your book is is how

we used to run

um in terms of, you know, I was at the

foot doctor.

What's it called? I I don't know what

they're called. Orthopedic Podiatrist.

That's what I said. Podiatrist.

What did I say?

But I went to the podiatrist the other

day because I

I got this

What's it called when your

in a point out on my foot. This part of

my foot here started to get lots of

pain. Every

Plantar fasciitis.

That's it. Plantar fasciitis. I started

to get some plantar fasciitis.

And it was just this ongoing pain.

And they prescribed me some insoles. I

stood on a couple of machines, some soft

stuff, and they measured my foot and

took this scan of it and said, "Right,

basically you're standing wrong.

Um your arch is a bit too flat. Take

these insoles and wear them in all of

your shoes." And I just I always think

in these moments when someone prescribes

me something that's not natural, I go,

"Why? Like

where did I go wrong?"

And I think that's the key question.

Where did I go wrong? Who lied to me?

To the point now that at 30 years old, I

have these bloody insoles that I have to

put in all my shoes. Because presumably

that's not natural. Presumably my my

ancestors don't have bloody insoles.

Yeah.

So,

plantar fasciitis is what I would call a

mismatch disease, right? A disease

that's more common or more severe

because our bodies are inadequately

adapted to modern environments. And in

your case, and as as is the case with a

lot of people, you have a weak foot. So,

so we you know, you you look like you go

to the gym. Looks like you're pretty fit

person, right? I'll make a bet you you

strengthen pretty much every muscle

group in your body except your feet,

right? No comment. Right?

Well, but we don't, right? And one of

the reasons is because we we encase our

feet in stiff-soled shoes that are very

comfortable. And and the reason the

shoes are comfortable is that your your

foot muscles have to do less work when

you're you're using those shoes, right?

We have shoes that are stiff soles,

they have arch supports, right? And your

your foot has four layers of muscles in

them. And those muscles are supporting

your arch. And at the bottom of those

four layers of muscles is this layer of

connective tissue, the plantar fascia.

And the problem with the plantar fascia

is that if it stretches too much, it

like anything else, right? It gets

inflamed.

But it's got almost no vascularization,

right? So, it has it's very hard for it

to repair itself when it gets inflamed.

To prevent plantar plantar fasciitis,

the best way to preventing it is having

a strong foot. A strong foot is a

healthy foot. So, the way to way to

treat the disease

in the long term is to strengthen your

foot. But if you want to just alleviate

the symptoms, that's what your

podiatrist did by giving you an insole,

right? It's basically

preventing your muscle your arch from

collapsing as much, making it more

comfortable so your your plantar fascia

gets stressed less, and so it can kind

of

um alleviate that that that that that

stretching and hence the pain, right?

So, that's a typical example of what I

call disevolution. It's what

what happens when you treat the symptoms

of a mismatch disease rather than their

causes or preventing their causes. So,

podiatrists are a bit like drug pushers

in that sense, right? Because they're

they're essentially

putting your foot in a cast, right? And

then and for the rest of your life, you

kind of have to keep using them unless

you strengthen your feet. So, I So, So,

there's nothing wrong with those, you

know, treating the symptoms. I mean,

pain is no fun. So, wear the insoles,

right? To kind of, you know, alleviate

the pain, but also work on strengthening

your foot, and I think you'll find that

the plantar fasciitis will will

disappear and never come back. So, the

plantar fasciitis fasciitis um has now

healed

after about a month of wearing the

insole. Um I no longer have the insoles

um with me here in

New York, and I don't have them in any

of my shoes because I've also taken a

bit of time off um running on my feet. I

was playing a lot of football.

So, now I'm at a point where I can go to

the preventable stage, prevent it

happening again. And you said to

strengthen my foot. How does one

strengthen their foot?

Good question. So, there are some

exercises. Um they're kind of foot

doming exercises and things like that.

But they're they're, you know, I can

send you some links to videos showing

you some good foot strengthening

exercises. So, that's one way to do it.

Um but the other way is to wear more

minimal shoes. Um to wear shoes that

aren't stiff-soled, that don't have arch

arch supports. Go barefoot a lot, right?

Um and those that will naturally

strengthen the muscles in your foot cuz

you'll have to use those muscles. So,

you ever gone for like a long walk or

run on a beach, right? And afterwards,

your your feet are kind of tired. Mhm.

Right? The reason your feet are tired is

because you're now working on a

compliant surface, right? It's not

stiff. So, your muscles having to work

more

to stiffen your foot to push you

forward, right? Jack, could you go grab

my the black shoe out of my bag? I just

want to show him something. So, um so,

wearing shoes that aren't as stiff-soled

when they don't have a arch supports

will slowly strengthen your feet. But,

and this is a huge but, if you do too

much too fast, you will your plantar

fasciitis will come roaring back and

you'll hate me. You'll like you'll never

forgive me because um

Yeah, there's a Vivo barefoot. Um yeah,

I I wear the same shoes.

Oh, you you've got the same shoes on.

Um great shoes. Yeah, those are

wonderful shoes. Those are those are the

those are the exactly the kind of shoes

that will help strengthen your feet.

These are fairly a new addition in my

life. Yeah, they and they feel really

strange cuz you can kind of feel the

floor. Yeah, it's exactly what you've

described is

Yeah. But but you you can transition. If

you have weak feet, which I'm going to

guessing you do, you if you go if you

suddenly that's the only shoe you wear

all the time,

you'll probably regret it, right? So, so

slowly slowly slowly increase the

percentage of time that just like

anything else, right? If you if you like

suddenly decide to lift, you know, huge

weights that you can't lift before,

you'll hurt yourself, right? The same

thing is with your feet. So, so slowly

it does it, but you if you do it

gradually and slowly and carefully, you

can build up strength in your foot and

and you'll

and you'll be a happier happier person.

And this is this goes back to everything

else you've said about how choosing

comfort, choosing to have a nice

supportive shoe has actually just kind

of deferred a problem off into the

future for me. It's the same with diet.

It's the same with avoiding and being

sedentary and and all these other things

where when you choose the easy road in

the short term, which is this wonderful

cushioned shoe I've chosen, the muscle

hasn't built up in my foot, and I've

paid the price. Correct. So, I need to

again choose discomfort more in the

short term, go up the stairs,

run barefoot to avoid the late the

consequences later down the line. Yeah,

I mean, I don't think you have to run

barefoot, but

though it can be fun, but um

um but yeah, I mean, and I can think of

plenty of other examples. Um

We love comfort, but comfort's not

necessarily good for us.

When you um when you look at these

tribes, are they

Do you know who Liver King is?

Huge massive muscles, talks about

ancestral living. Um

What do our hunter-gatherer ancestors

look like in terms of that?

Not like him. No? Okay.

I mean, look, think about it. Muscle is

really expensive, right? It's actually a

super expensive tissue. Uh about a third

of our body is muscle, and it's using up

about about you know, a fifth or more of

the calories that we're expending,

right? Uh just just sitting there, not

even using them, right? They're they're

very costly tissues, right? And so, if

you have more muscle than you need,

you're basically

adding to your your cost of of living,

right? And if you're if you're a

hunter-gatherer or even a subsistence

farmer living on the margin of food

security,

having more muscle than you need is

actually deleterious, right? Remember,

the only thing that natural selection

cares about is how many offspring you

have who survive and reproduce. Doesn't

care if you're strong or healthy or nice

or loved or, you know, fun or whatever.

It only cares about whether you have

grandchildren. That's it, right? That's

the cold calculus of selection. My brain

is going if I have big muscles,

I'll have more romantic opportunities,

and I'll have grandchildren. Well, only

up to a certain point, right? And I

don't So, if more muscles if if they

attract the opposite sex and and make

them want to reproduce with you, yes,

that could be a benefit.

Um I'm not so sure how much women are

attracted to the Liver King, but um um

and that's not something I even want to

know the answer to, but um and certainly

shouldn't ask him, but um

um

um but but there's a reason we have use

it or lose it, which you mentioned

earlier, right? Because

when we need

when we increase our demand, we increase

our capacity, right? When you go to the

gym and you work out, right? You build

muscle, but if you stop using those

muscles, you lose it. And that's an

adaptation, right? Because you don't

want to spend extra energy on muscles

you're not using, right? So, you want

enough but not too much. You want to be

economical with muscle mass, right? Um

and so, uh if you look at the data um

from hunter-gatherers, and people have

done that. They've done grip strength

tests, etc., and all kinds of other fun

things with it. Like mini Olympics. I

mean, we've done this, too. Um People

are reasonably strong, but they're not

super strong. And they're not they're

not buff and built and bulked and all

that sort of stuff. They've got enough

muscle to do what they need to do, but

no more.

And the reason why people find muscle

attractive anyway is because it's a

evolutionary signal, isn't it, of

uh reproductive value and resources,

maybe, and your ability to go out and Do

you know what I mean? Why why does why

does a woman, for example, find a man

with muscles or in good shape attractive

in 2023 when we're not hunting for

gazelle?

Well, I'm not a I'm not a I'm not a

psychologist or a or so, I'm not sure if

I'm qualified to answer that, but I

could I could venture the guess that

obviously, if you're trying to if, you

know, we pair bond as a species, and we

have been for for of years probably.

You want to pair bond with somebody

who's going to because we also have of

cooperation and food sharing, right? You

want to prepare bond with somebody who's

going to be able to you know bring home

the bacon literally and figuratively,

right? But but bringing home the bacon

does not mean looking like Arnold

Schwarzenegger at least back in the day

Arnold Schwarzenegger back in the day,

right? Being bringing home the bacon

back in the day meant being

a persistent hunter being able to run

long distances and being moderately

strong. So they looked more like a

marathoner or or a football player than

they did a

weightlifter, right? So it's conceivable

it's conceivable that someone who is

really really big is actually

um less attractive because they wouldn't

have been able to hunt and run and hunt

as well as someone who was a little bit

Yeah, you also have to you have to feed

what they you have to feed them more,

too. Yeah.

And that's a you know those are precious

calories. So I'm going to guess that uh

I look if you look in in in non-Western

populations

you don't see physiques like that. This

is a this is a privilege of people who

are able to go to gyms and

and you know eat you know

you know whey powder shakes and all that

kind of stuff to kind of build their

crazy muscle mass, but it's not

something that our ancestors were able

to do on a regular basis. That's for

sure.

A quick word on Huel. As you know

they're a sponsor of this podcast and

I'm an investor in the company. One of

the things I've never really explained

is how I came to have a relationship

with Huel. One day in the office many

years ago a guy walked past called

Michael and he was wearing a Huel

t-shirt and I was really compelled by

the logo. I just thought from a a design

aesthetic point of view it was really

interesting and I asked him what that

word meant and why he was wearing that

t-shirt and he said this is brand called

Huel and they make food that is

nutritionally complete and very very

convenient and has the planet in mind

and he the next day dropped off a little

bottle of Huel on my desk and from that

day onwards I completely got it because

I'm someone that cares tremendously

about having a nutritionally complete

diet but sometimes because of the way my

life is that falls by the wayside. So if

there was a really convenient reliable

trustworthy way for me to be

nutritionally complete in an affordable

way I was all ears especially if it's a

way that is conscious of the planet.

Give it a chance. Give it a shot. Let me

know what you think.

There's another myth that I you bust

which I thought was really interesting

cuz I think I know a lot of people that

have used this as a as a reason not to

run. They say it's really bad for your

knees. Oh man, that gets me so mad,

right? I mean I hear this from doctors

all the time, right? Oh yeah, running is

bad for your knees. Now it is true

that knee injuries are the most common

running injuries. Um um

but

arthritis which is really what they're

usually talking about um it's absolutely

definitively not true that running

increases rates of knee cartilage damage

and arthritis. So arthritis is caused by

cartilage wearing away in a joint,

right? And it's it's a it's a myth that

that running actually increases

cartilage damage. If you have arthritis

running is excruciating and problematic,

but if you don't have it running

actually

if anything may be slightly preventive

um because

cartilage joints like everything else

benefits from being used, right? 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're 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 um um

and of course the other thing about

running is that I think a lot of people

run incorrectly today. So

so that's why we started studying

barefoot running millions of you know a

long a few a bunch of few decades ago is

because if humans have been running for

millions of years most of that time we

were running barefoot. So I'm kind of

curious how did people run before shoes