- I'm ready to rumble.
- Everyone worries, I think, about death.
And so people have always questioned
whether this was something that you could actually control.
A lot of people don't realize
how much power we actually have over our aging process.
- Aging is a subject matter
that seems to be shrouded in all kinds of mystery.
I don't believe aging is a bad thing.
I believe that we should want to age well
inside and out, and it is possible.
- What is that lifelong story,
that trajectory of what we should be doing
for our gender, for our age,
for our genetic background
that will make the aging process most beautiful for us?
- Physical exercise and good health.
Those things act importantly to reduce the likelihoods
and eliminate age-related memory loss
or at least significantly restrict it.
- We evolved to live long in order to be physically active
and that physical activity helps us
to live longer and stay healthy.
- Hey, Big Thinkers, your metabolic health
is one of the biggest predictors of how long you live,
and how good you feel while living.
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Now back to the science of exercise and longevity.
- We know that there is sometimes a disconnect
between this concept, what we call lifespan and healthspan.
So lifespan is just the time you've been alive
between birth and death.
And what scientists think healthspan is,
is the time you're alive
in a more healthy functioning state.
We want to increase quality of life
and maintain that over time.
And if that produces a longer life, that's an extra bonus,
but that's not the ultimate goal.
So usually when we think of changes associated with old age,
we think of functional changes.
Things like how fast you can run or walk
or your ability to go up stairs.
Aging is really personified by dysfunction
and we see a lot of this in the diseases
that tend to arise with aging.
- So as people age, they're susceptible
to one of two kinds of cognitive declines.
One is Alzheimer's disease, which begins in the 70s,
but becomes almost an epidemic
when people are in their 90s
when almost half the population has Alzheimer's disease.
And the other, quite distinct from Alzheimer's disease,
is called age-related memory loss.
That differs from Alzheimer's disease
in the sense that it starts early, starts in midlife,
and involves a different part of the brain.
It starts in the dentate gyrus.
Alzheimer's disease starts in the entorhinal cortex.
- But other things we associate with aging
are also changes in body composition.
So often people will maybe gain fat mass around their middle
or lose muscle mass.
- And one of the real serious most pernicious issues
of aging is a problem called sarcopenia.
"Sarco" is flesh and "penia" is loss. So it's flesh loss.
As people get older, they tend to lose
a lot of strength and power,
and that makes basic tasks difficult.
And when that happens, people become less active.
When they become less active, they become less fit.
And it kind of sets in motion
a really disastrous vicious cycle.
And so, as we get older, strength training
becomes more and more important so that we can avoid
those losses of vigor that are really important
to maintaining your health
and staying strong and staying healthy as we age.
- Lifestyle right now is actually our best ticket
in terms of slowing our aging process.
And this is really because living systems are adaptive.
We adapt to our environment,
we adapt to the things we experience.
So you can actually boost things
like resilience through different lifestyle behaviors.
- And so healthspan is really the key thing.
And what physical activity does
is it increases your healthspan,
and your healthspan therefore increases your lifespan.
So the word exercise comes from the Latin "exercitatio,"
and it meant to train.
I would say that the definition I use
of exercise is pretty much the bog standard definition
that people in the sort of fitness,
exercise science world use.
So it's important to make a distinction
between physical activity and exercise.
So physical activity is just moving.
You do anything. Go shop.
You know, pick up your groceries and take them to your car.
That's physical activity.
When you sweep the kitchen floor, that's physical activity.
But exercise is discretionary,
voluntary physical activity
for the sake of health and fitness, right?
It's planned.
So it can include everything from sports
to running on a treadmill, to, you know, going for a walk.
- Every single time you move your body,
including when you're running,
you are giving your brain what I like to call
"a wonderful bubble bath of neurochemicals."
Those neurochemicals include dopamine, serotonin,
noradrenaline, endorphins,
but it also includes what's called growth factors.
Several different growth factors get released with movement,
and that is going towards the long-term effects of exercise
that can actually help grow and strengthen
two key brain areas:
One is the hippocampus, critical for long-term memory.
And the second is the prefrontal cortex,
critical for your ability to shift and focus attention.
The hippocampus is an extraordinary structure
because it is one of the only human brain areas
that can grow brand new brain cells in adulthood.
And what does that mean? Your memory is better.
The other brain area that benefits
in terms of growth and strength is the prefrontal cortex.
Now, it's not growing new cells.
Some evidence suggests that the outputs of cells
in the prefrontal cortex called the axons of those cells
perform better, work better with more exercise.
- But there's another benefit, right?
And the other benefit is that that physical activity
is important because when you're physically active,
you stress your body.
You produce what's called reactive oxygen species,
which cause cellular damage throughout your body.
It causes mutations, it causes inflammation.
But because that's normal,
our bodies turn on all kinds of repair
and maintenance mechanisms that counter those.
And as we get older, that repair and maintenance
becomes really important because it prevents senescence,
it prevents our bodies, from decaying.
So when people become physically inactive
as they get older, they're no longer turning on
those mechanisms that we evolve to use, right,
that help us age better,
and it makes us more vulnerable
to disease and we age faster.
- So when we think of stress, we often think stress is evil,
but in reality, stress is designed to make us stronger,
whether it's emotionally or physically.
Somebody has osteoporosis or osteopenia, right?
They have their bone density is becoming compromised
with "old age."
Okay, well, why do we recommend working out,
in particular with weights?
The idea is that stress is an injury.
We're injuring the muscles, we're injuring the bones, right?
The bone remodels and becomes more dense.
- Your bones are an endocrine gland.
They release a hormone called osteocalcin
and it enhances the memory storage in young people,
but also enhances memory storage in old people.
And one of the reasons that exercise is important
is because exercise builds up bone mass.
This is particularly important in women,
where bone mass tends to decrease more dramatically
than in men, but it's important for everybody.
So when you exercise, you increase your bone mass,
you increase osteocalcin,
and you improve age-related memory loss.
- So as we get older, let's not cut back
on the physical activity, let's maintain it.
Do some strength, do some endurance.
The evidence is incontrovertible.
The more we age,
the more physical activity is really beneficial.
According to the CDC,
only about 20% of Americans
get the very minimum levels of exercise
that every health organization in the world
thinks is the minimum for an adult:
which is 150 minutes a week.
So 80% of us really struggle
and fail to get very basic amounts of exercise.
But almost everyone
says that they want to get enough exercise.
You know, nobody ever exercised in the Stone Age, right?
People were physically active when they had to be,
but volitionally going on a 5-mile run in the morning
or going to the gym to lift weights
whose sole purpose is to be lifted?
That's a really strange, weird, modern behavior.
And there are all kinds of instincts that we have
not to do it, and we shouldn't make people feel bad;
instead, we should help them figure out
ways to overcome those instincts.
- And so in order for these behaviors in the moment
that are less than pleasurable to become manageable,
you've got to have perspective
and a long-term goal that's worth it.
And we call that "Finding your why?"
Is it, "I wanna wear a two-piece
instead of a one-piece at spring break because I'm 22?"
Or is it,
"I want to see my grandchildren graduate from college
because I'm 62?"
Whatever your motivation is, that's what's critical.
You need to think about
what ways health will improve the quality of your life,
because I'm gonna tell you right now,
that getting healthy usually is dis-pleasurable.
- So everybody wonders
about what is the best time to work out.
And my first answer to that question
is always anytime you can fit it in,
from morning till night, fit it in.
Physical activity is the most transformative
thing that you can do,
not only for your body, but for your brain as well.
That is the key message.
And you don't have to become a marathon runner
or triathlete to get these benefits.
- In fact, lots of research
shows that physical activities
like running actually cause your joints
to repair themselves and to stay healthy.
But you have to learn how to do it properly.
One of the the ways in which we medicalize exercise
in the Western world
is we think there's a certain amount you should do, right?
We prescribe it, you know?
You should take two aspirin,
you should get eight hours of sleep,
and you should walk 10,000 steps a day.
You know, we like that, right?
And there's nothing necessarily wrong with a goal.
If you do 8,000 steps, that's fine.
If you do 15,000 steps, that's fine.
The important thing is to get, you know,
be physically active because some is better than none.
There's no magical number.
- I like to set smaller goals for myself. Doable goals.
That is the key.
Maybe it is a walk on the shore, a walk to the gym,
a walk around the museum with friends.
Gardening. People think those things don't count.
They all count.
Be more broad in your definition
of bringing more movement into your life.
- So, is science gonna actually solve death?
The important thing is that death is not the ultimate goal
in terms of aging research.
What we really want to do
is keep people healthy and functioning
for as long as possible.
And if that results in a longer life expectancy,
that ends up just being the added bonus.