Back when I was still in school,
there was this stereotype going around.
Kids who were nerdy and never did any kind of sports
were considered the most intelligent and bright.
The jocks who were sporty and fit,
were often branded as simple-minded and empty-headed.
So by following this stereotype you had two groups:
Smart and weak;
Dumb and fit.
However in the recent years, there’s a new stereotype that’s gained popularity:
A smart jock,
an individual who is both intellectually gifted and is physically fit.
Did they win the genetic lottery
or is it possible that exercise could make you smarter?
First we need to take a look back in the past before we can draw any conclusions.
Not that long ago, there was this prevailing theory that we had a fixed amount of brain cells.
You were either born smart, with a big brain,
or you weren’t.
And once we became adults our brains were supposed to stop creating new neurons,
and we could only lose neurons as we got older.
Saying the brain could grow and form new brain cells,
got you ridiculed and made fun of by the scientific community.
However in the mid 90s
some scientists were looking for a way to prevent Alzheimer’s disease.
For those that don’t know,
Alzheimer’s is the most common cause of dementia,
a general term for memory loss and other cognitive abilities.
It’s identified by a loss of neurons in certain brain regions.
To put it simply, the disease shrinks your brain.
Over the 4 year period,
the scientists found 3 factors or 3 lifestyle changes,
科学家们发现 有3种因素 或者说是3种生活方式
that actually helped prevent the cognitive decline in Alzheimer’s disease.
The first factor was continuous learning and education.
Things like reading books and learning more about the world around us, fall in this category.
The second was self efficacy and mindset.
Basically an individual’s belief in their innate ability to do things well
and achieve their goals.
But third and last, was physical exercise.
The first two factors weren’t so surprising, but the third one was.
How could exercise be the most potent lifestyle change you could make to keep your brain going?
As far as we knew, exercise didn’t act on the brain.
One of the scientists of the group, Carl Cotman,
went back to his lab and decided to study what’s going on.
So he got a bunch of mice
and had them run on a running wheel from 7 to 14 days.
But it wasn’t all funny games for the mice,
as their brains were eventually dissected.
He looked at their brains and the cortex,
which is the top part of the brain, was thicker.
And there was one particular area called the hippocampus which was bigger,
when compared to the mice that didn’t run on the wheel.
The brain’s cortex is where our long term memories are stored.
And the hippocampus is like a center for learning and short term memory.
So Carl found the answer he was looking for.
Exercise was making our brains grow new cells and neurons.
This is why it was preventing brain’s deterioration
and cognitive decline.
Carl’s findings paved a way for a whole new research field in science,
by showing the world that the brain is astonishingly flexible,
able to be retrained and reprogrammed.
Like a muscle, it responds to use,
adapting to new demands and conditions.
It also withers without use.
So it’s either use it, or lose it.
However that doesn’t quite explain
why exercise is making our brains grow new neurons.
Most people would consider “using your brain” as doing something creative or logical,
大多数人认为“用脑” 就是做有创造性 逻辑性的事
like writing a book or solving a puzzle.
But that’s not really what the brain’s main function is.
The only reason why humans have such big brains is for one purpose,
and that purpose only.
And the reason is to perform adaptable complex movements.
Simply put, we have a brain made to move.
As pointed out by a neurophysiologist Rodolfo LLinas,
only a mobile creature needs a brain.
To illustrate this, he used an example of a tiny jellyfish like animal,
called a sea squirt.
Born with a simple spinal cord and a three hundred neuron brain,
the sea squirt moves around in the ocean until it finds a coral rock,
where it will spend the rest of its life.
However once safely attached,
the sea squirt simply digest its own brain for extra energy.
For most of it’s life, it looks much more like a plant than an animal,
and since it’s not moving anymore,
it has no more use for a brain.
When we bring the word “exercise” to mind,
we might think of someone trying get it in shape or becoming buff.
However today we know that
exercise has a much bigger effect on our brain, than on our body.
Physical activity activates most of your brain regions simultaneously,
because like we just said, we need a brain to move.
Conditioning the heart and building muscle are essentially side effects.
But the most profound effect exercise has on our brain,
is that it improves our learning ability.
We mentioned earlier that
the mice that ran on the running wheel had a bigger hippocampus,
which is the brain’s center for memory and learning.
The reason it was bigger is because when we exercise,
we raise our levels of BDNF.
BDNF or brain derived neurotrophic factor
is a powerful protein that stimulates the production of new brain cells
and strengthens existing ones.
It’s found in the hippocampus, cortex, and basal forebrain.
All these brain areas are vital to learning, memory, and higher thinking.
BDNF can be compared to a plant fertilizer.
Plants need water, sun and soil to grow.
However most soil doesn’t provide
the essential nutrients required for optimal plant growth.
This is why plant fertilizer is added.
Just like a plant fertilizer supports plant growth,
BDNF acts as a brain fertilizer.
BDNF nourishes brain cells and makes them grow new synapses.
A study in 2013 showed that
just 20 to 40 minutes of exercise
increased BDNF in the blood by 32%.
This ties closely to the German study,
where they found that people learn vocabulary words 20% faster after physical activities.
And the rate of learning is directly correlated with the levels of BDNF.
To put it simply, the higher our levels of BDNF are,
the easier it is to learn new things.
And if you’ve been paying any attention right now,
you know what gives a significant boost of BDNF.
Which brings out a more interesting question;
is there a correlation between fitness and academics?
Only a few researchers have tackled this question.
However a study from Virginia Tech showed that
cutting gym class and devoting more time to math, science and reading,
did not improve test scores as many assume it would.
Cutting away exercise and spending more time behind the books
could actually decrease your test results.
Over the past few years the California Department of Education has consistently shown that
students with higher fitness scores also have higher test scores.
In 2001 study, kids who were fit, scored twice as well
on academic tests as those who were unfit.
Body mass index and aerobic fitness were the most significant contributors.
This means that if you want to get better grades,
you might want to start by lacing up your running shoes, before hitting the books.
There’s a school in Naperville Illinois that took full advantage of this.
Over the 20 year period, they evolved their PE program to one of the best in the world.
The program was started in response to research
which linked exercise to increased brain function.
As a result, they have turned 19,000 students in Naperville District 203,
into one of the fittest in the nation.
Only 3% of them were overweight, without a single obese child.
This was at a time when 33% of America’s kids were overweight,
with this number increasing to 37% over the past years,
and still no sign of stopping.
What’s more interesting is that the Naperville program
has also turned those students into some of the smartest in the nation.
In 1999 Naperville’s students took an international test called TIMSS,
which evaluates knowledge of math and science of different countries.
Almost every year the Asian countries score the highest,
while United States is usually in the mid teens,
but Napperville is an exception.
The students took the test as a country, to see how they would perform,
and they finished sixth in math and first in science.
Sixth and first in the world, as a school.
Wow. Not only that,
but 97 percent of the 8th graders took the test,
so it’s not only the top students who were picked for it.
How did they do it?
As I mentioned they were the fittest school in the nation.
The key word here is fit.
Fit doesn’t mean you’re skinny.
The benefits of exercise don’t kick in with your shape and size,
but it has a lot to do with what you’re doing.
It’s much better to be overweight, but active daily, than being skinny and inactive.
Like I said, building muscle or losing weight
are essentially side effects that will come over time.
When students from Naperville go for a mile run,
they are more prepared to learn in their other classes.
Thanks to exercise, their focus and mood are improved
and they feel more motivated and less tense in school.
That’s why their early morning PE program is called “Learning Readiness” class.
Physical activity primes the brain for learning
and if we look at it from an evolutionary standpoint,
it makes perfect sense why.
Often we forget that humans evolved as hunter gatherers.
It’s only in the last few centuries that our lives have become more sedentary.
However, evolution doesn’t work that fast,
and today we still have the same brains as our ancestors.
As little as 10,000 years ago we were still hunting and gathering,
至少1万年前 我们仍旧在打猎 采集
and we moved anywhere from 10 to 14 miles every single day.
We were foraging for food, constantly moving from place to place,
looking for a new shelter.
If you weren’t fit enough to run, climb or swim,
如果你不能跑步 攀爬 游泳
you were removed from the gene pool.
As far as our brains are concerned,
physical activity counts as a novel experience.
Whenever we were moving, it meant something important was happening.
We had to escape from a predator
or remember the path we took so we didn’t get lost.
However when we were resting, it meant nothing important was going on.
然而 我们休息时 就表示没发生重要的事
We still have this ancient mechanism, so as far as our brains are concerned,
if we are not moving, there’s no reason to learn or remember anything.
So what kind of physical activity should you do to reap the most benefits?
The answer is high intensity aerobic exercise.
Going to the gym and lifting weights every 10 minutes, like many powerlifters do,
去体育馆 像举重运动员那样 10分钟做一组举重
doesn’t seem to have such a powerful impact, as high intensity exercise does.
Powerlifting still benefits the brain, don’t get me wrong.
However if you want to get the most out of it,
you need to get your heart rate to at least 80% of its maximum beats per minute.
Some of the best activities are running or cycling.
But it’s even better if the activity involves some complex motor movements,
and it’s not just putting one foot after the other.
Good examples are tennis and dancing.
Optimal daily dose of exercise seems to be 20 to 40 minutes in the morning.
For some people the benefits last for the whole day,
but for the majority they seem to last for about 2-4 hours.
This is why it might be a better idea to break it down in to smaller segments.
So let’s say you do 20 minutes of your core exercise in the morning
and then exercise 2 times for 5 minutes throughout the day.
This way you can extend the benefits.
If you haven’t been active for a while, it’s better to slowly build up to those times.
30 minutes is just a recommendation and not a requirement.
Even just walking for 30 minutes could have a powerful effect.
It’s up to you to find your optimal dose,
depending on your schedule and personal needs.
So to answer the question, can exercise make you smarter?
Going for a run sadly won’t turn you into a genius.
But it will prime your state of mind and at the cellular level,
improve the brain’s potential to log and process information.
You will be able to learn things faster and more efficiently.
However it’s up to you to put yourself in a situation where you’re actually learning something.
If you go exercise and then right after go sit on a couch while watching TV series,
you’re not learning anything of value.
But if you put your mind to it and try learning something new,
whether it’s a new skill or just studying for the test,
you will find that it’s much easier to do so.
By knowing more about the world around you and how things work,
you could say that, yes, you’ve become smarter.
We all have the ability to boost our brainpower
and all we need to do is lace up our running shoes.
Thanks for watching.
I hope this video made you better than yesterday.