Exercise: Crash Course Study Skills #10

Hi, I’m Thomas Frank, and this is Crash
Course Study Skills. Over the course of the past nine episodes, we’ve
covered the topics that you’d expect to fall under the
umbrella of this show’s “study skills” subtitle – preparing for tests, planning, beating
procrastination, and so on. Today we’re going to step slightly out of
that umbrella’s shadow to talk about exercise. But don’t be fooled – this video will
still help you to become a better student. Exercise is crucial for keeping both your body and
your brain healthy, and as you’ll see later in this video, it’s also a simple way to improve your
ability to learn and focus. The problem is that our culture is becoming
less and less active. Here in the U.S., nearly a third of kids between the ages
of 2 and 19 qualifies as either overweight or obese. And on average, we spend over 10 hours a
day looking at screens – an activity that almost
always involves sitting down. And many schools aren’t helping the issue, as
physical education programs are constantly being
cut in favor of adding more time to other classes – even though, as you’ll see in a minute, there is
evidence to show that the opposite tactic would
produce better academic results. So today we’re going to dive deep into the
brain benefits of exercise. And keep in mind here that we’re not talking
about a narrow definition of exercise, like
lifting weights or running. Exercise comes in many different shapes and forms, and
regardless of your skill level or physical limitations, you
can probably find something that gets your heart rate up – which can, in turn, improve your mind. [Theme Music] When we think about the concept of
“learning”, we often picture someone lost in
some kind of intellectual work – doing research, reading a book, or maybe
working through a bunch of math problems. But it’s important to realize that all of these
activities are relatively recent inventions when
looked at on an evolutionary time scale. Let’s go to the Thought Bubble. For the vast majority of the time that the
brain has been around – be it inside the skull of a human or something else – its
ability to learn evolved right alongside movement. And this makes sense if you think about it. Lifeforms that don’t need to move really
have no use for a brain. Plants just need to take root in one spot
and then grow upward, and for that, a fixed set
of genetic programming will do just fine. The ability to learn, think, and strategize
only becomes necessary when you can move around, because now you need to be able to navigate a
complex environment, find food and remember its
location later on, and escape from predators. If you want a good example of this difference,
look at the sea squirt. These invertebrates start their lives in a
larval stage complete with a primitive eye, a tail-like nerve cord that lets them move
around, and a brain. At this stage, their goal is to find a spot
on the ocean floor where they can attach themselves. Once they do this, that’s where they’ll
be staying for the rest of their lives. And to seal the deal, they absorb all of those
useful features that let them move around – the eye, the nerve cord, and – you guessed
it – the brain. That’s right – once a sea squirt doesn’t need
to move anymore, it basically eats its own brain. Thanks, Thought Bubble – I think? The neuroscientist Rodolfo Llinás used the case of the
brain-eating sea squirt in his book I of the Vortex: From
Neurons to Self in order to illustrate his conclusion that: “That which we call thinking is the evolutionary
internalization of movement.” In other words, brains are for creatures that
move. Once you stop using it, you lose it. In fact, “use it or lose it,” is a principle that
applies to much of biology – not just brains. That’s why your muscles can start to atrophy
if you don’t use them for long enough, and why failing to stay active and learn new
things can greatly increase the risk of developing
dementia as you get older. To use an even more extreme example, astronauts
that spend a lot of time in orbit often suffer from a
condition called spaceflight osteopenia, which is a loss in bone density that happens
because the skeleton doesn’t have to constantly
fight against the pull of Earth’s gravity. On the whole, every part of your body is adapted
to allow you to do specific things. If you aren’t doing them, then those parts
of your body simply become resource hogs. But you can’t just decide you don’t need
them and turn them off – your body’s systems are highly connected
and they depend on each other, which means that you need to do what your
body is built to do if you want to keep it all working. And in the case of exercise, it’s not just
a matter of “working” or “not working” – in addition to keeping you healthy, getting
your heartbeat elevated on a regular basis
can also make you a better student. Just look at the school district of Naperville,
Illinois. Back in the year 1990, a P.E. teacher in Naperville
named Phil Lawler decided that the traditional structure
of P.E. classes just wasn’t going to cut it anymore. Since they were almost always based on sports,
the few kids who were already athletic would naturally dominate the more active roles, and by
consequence, lots of other kids would end up just
standing around – not really doing much at all. Lawler decided to change things up, and he
shifted his class’s focus from traditional sports
to more fitness-based activities like jogging. He placed an emphasis on constant movement
and keeping heart rates in an elevated zone
during the entire period. And – most importantly – he graded his
students on effort rather than skill. By using heart rate monitors, he was able to tell that
students who clocked 10 minute mile times were still
working just as hard as those who could finish in 8. He called this program Zero Hour P.E., and it started
as an optional morning program before becoming
integrated into the school’s normal schedule. By the end of its first semester in 1990, his test
group of students showed a 17% improvement
in reading and comprehension, compared to a 10.7% average improvement
for the kids who didn’t participate. After that, the structure of Zero Hour P.E.
became the archetype for the entire district’s
physical education program. And today, the district consistently ranks in
the state’s top 10 academic performers, even though money spent per student there
is much lower than other top-tier districts. The correlation between fitness-based P.E. classes
and higher grades isn’t limited to Naperville, either. After studying Lawler’s program, another P.E.
teacher named Tim McCord brought it to his own
school district in Titusville, Pennsylvania. And in 2008, eight years after the program had
started there, the district’s reading scores had gone
from below the state average to 17% above it. Likewise, math scores went from below the
average to 18% above it. So what’s going on here? How exactly does exercise help you become
a better student? Well, broadly speaking, regular exercise improves
your brain in three important ways. First, it optimizes the levels of neurotransmitters
like serotonin, norepinephrine, and dopamine. These are all crucial for learning. Keep in mind that we are hugely oversimplifying
things here, but in general, serotonin helps to
regulate your mood and keeps you happy. Norepinephrine amplifies signals related to
attention and motivation, and dopamine is highly involved in learning,
movement, and operating the brain’s reward center. Regular exercise balances these neurotransmitters,
along with lots of others that are equally important
for keeping your brain healthy. Secondly, exercise can also stimulate
neurogenesis, which is the birth of new neurons
from neural stem cells in the hippocampus. This was once thought to be impossible. For a long time, the prevailing belief in the
scientific community was that you were born with
all the neurons you were ever going to get. But we now know that new neurons are
created even during adulthood, and exercise
increases their rate of creation. Now, one important thing to note here is that
these new neurons are born as stem cells that
don’t have an immediate purpose. As a result, many of them die – again, “use
it or lose it.” In order for a new neuron to survive, it has
to get plugged into an existing neural network,
and that happens when you learn new things. So really, the crucial combo for this
particular bit of brain optimization is regular
exercise AND constant learning. Now if you’re a student, you’ve probably
got the second part down pat at the moment, but I do want to mention this, since it
remains true even as you get older and eventually
don’t have to go to school anymore. Lastly, exercise improves the ability of neurons to
bind to one another, which is how new neural
pathways are formed and how memories take hold. It does this by promoting the production of a protein
called brain-derived neurotrophic factor (or BDNF), which in turn enables and improves a
process called long-term potentiation. This is the mechanism that enables learning. When new information enters your brain,
neurons start firing using existing stores of
another neurotransmitter called glutamate. If the firing continues, each active neuron
will also start generating building material
for the creation of brand new synapses, which are connections between separate
neurons. As these new synapses are created, memories
form. And BDNF is the secret sauce that makes the
whole process possible. In fact, researchers have discovered that
depriving rats of BDNF causes them to lose
the capacity for long-term potentiation. And, on the flip side, they’ve also found
that injecting BDNF directly into a rat’s
brain increases that capacity. Now, this does not mean that you should go ask
your doctor to inject BDNF in your brain – they’re
probably gonna give you a pretty weird look. And it’s unnecessary anyway, because your
brain naturally produces more BDNF when you
learn new things and when you exercise. There are also other benefits that go
beyond learning; research has found that regular exercise can also
improve your ability to focus and block out distractions, it reduces stress, and it lets you control
the weather with your mind. We don’t have time to dig into the details
of these benefits here, but if you’re curious, you can learn a lot more about each of them
in Dr. John Ratey’s book Spark: The Revolutionary
New Science of Exercise and the Brain. Except for that last one – I was lying about
that one. What we need to do now is answer the million-dollar
question: How, exactly, should you exercise if you
want to improve your brain’s performance? Well, first off, don’t try to do traditional
academic learning during intense exercise. You think it’d be a pretty sweet productivity hack to
study your organic chemistry flash cards during a set of
heavy deadlifts, but it’s not going to work out so well. When your heart rate is elevated, blood actually
moves away from your prefrontal cortex, which manages your executive functions, working
memory, and the intake of new information. However, that blood comes back almost immediately
after you finish exercising, so doing a workout or going
for a run right before you start learning is a great idea. As for how you should exercise – well, that’s mostly up
to you, but you’ll get the best results by combining an
elevated heart rate with complex, skill-based movement. One way to do this is to opt for a sport or
a skill-based activity that combines both, like figure skating, basketball, skateboarding,
martial arts, or even intense yoga. Alternatively, you can first do some aerobic exercise
followed by a lower intensity bout of skill based
movement, like going for a 15 minute run and then
doing some rock climbing. But beyond all else, just get started. Even going for a short walk once a day can
have a lot of benefits. So if you’re not getting a lot of exercise
right now, just start small, do what you can
do, and focus on building the habit. You don’t need to worry about finding the
perfect workout routine, or memorizing all the
details we covered about BDNF and neurons. If you can just build that habit, your brain
will take care of the rest for you. Over the course of this series we’ve covered
tips and strategies for dealing with many of the
biggest challenges you’ll face as a student, and we’ve done our best to use research
and our own personal experiences to make
those tips as useful as we possibly could. But as you dive into your work, you’re gonna
discover other strategies that might be even
more effective, or you’ll make tweaks that suit your style of working
better than anything we could come up with. And I’d encourage you to actively seek out these
improvements, as learning and productivity are two
fields where there’s no single set of “best” practices. As Bruce Lee once said, “Adapt what is useful, reject
what is useless, and add what is specifically your own.” And just as Lee himself strove to make this
cycle of self-improvement a lifelong process,
so should you. We’ve covered a lot of ground over the past 10
episodes, but there’s always more to learn – both
in the realm of study skills and beyond. So keep learning, keep improving, and don’t
forget to be awesome. Crash Course Study Skills is filmed in The Dr.
Cheryl C. Kinney Crash Course Studio right here in
Missoula, MT, and its made with the help of all
these nice people. If you’d like to keep Crash Course free for
everyone, forever, you can support the series
over at Patreon, a crowdfunding platform that
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