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Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff,

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Speaker 1: Lauren fog Bomb here. We've all felt it, the mental

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Speaker 1: fatigue after working a long day, taking finals, or running

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Speaker 1: errands all over town. That tired, dull feeling like the

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Speaker 1: hinges on your brain are rusty and they creak and

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Speaker 1: grown if you try to recall something or pay attention.

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Speaker 1: When this type of brain drain sets in, regardless of

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Speaker 1: how hard you try to concentrate, you probably find yourself

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Speaker 1: exhausted and unable to fully focus. Is this kind of

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Speaker 1: mental fatigue evidence that you've overworked your brain? Does your

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Speaker 1: brain actually get tired in the same way that your

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Speaker 1: muscles do? And is there any difference between mental fatigue

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Speaker 1: and good old physical exhaustion and is there any way

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Speaker 1: to prevent it? Of course, your brain isn't a muscle.

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Speaker 1: It does have a bit of muscle tissue, but it's

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Speaker 1: mostly made up of fat. In the brain, electric cells

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Speaker 1: called neurons transmit messages via chemicals, and although the brain

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Speaker 1: isn't muscle, it cells do use energy to function. The

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Speaker 1: sugar molecule glucose is the brain's primary source of that energy.

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Speaker 1: When glucose enters the brain, cells organelles called mitochondria convert

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Speaker 1: the glucose into a dentisine triphosphate, or a t P,

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Speaker 1: which is a complex organic chemical for storing and transferring

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Speaker 1: energy in cells. A group of researchers from Australia and

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Speaker 1: Belgium thought that the compound a TP could be the

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Speaker 1: key to brain drain. The idea was that when your

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Speaker 1: brain works hard, it uses up all that glucose, leaving

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Speaker 1: you feeling depleted. The lower glucose levels then raise levels

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Speaker 1: of a t P, which blocks dopamine, that chemical that

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Speaker 1: makes you feel good and keeps you motivated. The study,

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Speaker 1: which was published in the journal Sports Medicine, concluded that

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Speaker 1: when your brain can't get enough dopamine, you're less likely

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Speaker 1: to stay on task. So even though your brain isn't

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Speaker 1: a muscle chemically, you can tire it out by thinking

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Speaker 1: too much. We spoke with Melanie Greenberg, pH d, a

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Speaker 1: clinical psychologist in the Bay Area of California and author

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Speaker 1: of a book called The Stress Proof Brain. She explained

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Speaker 1: that humans aren't wired to do complex types of thinking

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Speaker 1: all the time. These executive functions are higher level cognitive

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Speaker 1: skills that let you monitor your goals and process information

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Speaker 1: in order to execute plans to achieve those goals. These

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Speaker 1: can include obviously challenging tasks like taking the l s at,

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Speaker 1: but can also comprise a combination of smaller challenges, like

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Speaker 1: meeting new people or navigating a route you're unfamiliar with,

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Speaker 1: or even resisting impulses like having another cookie or skiving

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Speaker 1: off work. Greenberg said, after a while, our brains automate

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Speaker 1: things and take less energy. For example, if you drive

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Speaker 1: the same way to work every day, that activity will

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Speaker 1: use less brain energy than if you had to constantly

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Speaker 1: find new roots. When your brain is dealing with an

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Speaker 1: ongoing supply of new information, it must put energy into

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Speaker 1: every decision, which overuses that executive function and can cause

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Speaker 1: mental fatigue. All using up available glucose in your brain

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Speaker 1: creates mental fatigue. Simply taking in more glucose won't fully

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Speaker 1: and immediately recharge your brain. Eating a snack to provide

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Speaker 1: glucose or having a coffee to up your dopamine can help,

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Speaker 1: but neither will eliminate the brain drain because the cellular

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Speaker 1: functions are more complicated than that. We also spoke with

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Speaker 1: Gary Fegale, m D, a geriatric psychiatrist in Atlanta, who

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Speaker 1: specializes in neurology and psychiatry. He explained that every brain

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Speaker 1: cell is connected to a hundred thousand other cells in

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Speaker 1: a highly integrated network, and when you're tired, your brain

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Speaker 1: has decreased blood flow and electrical activity. Scientists are still

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Speaker 1: in a hypothetical stage of understanding the brain, meaning they're

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Speaker 1: making a lot of educated guesses about how it works.

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Speaker 1: They know that rest is important, but they still aren't

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Speaker 1: sure why it's important to our brains. But Figel said

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Speaker 1: that if you simplify, you can say that there are

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Speaker 1: four steps to a well functioning brain. Glucose must be

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Speaker 1: available in the blood, Glucose must be efficiently transported inside

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Speaker 1: the cells. A glucose must turn the mitochondria, and the

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Speaker 1: mitochondria must produce a t P. Thus, a breakdown in

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Speaker 1: any of the four steps can be to blame for

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Speaker 1: mental fatigue. So, for example, even if glucose is available,

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Speaker 1: fatigue might happen when a cellular function slows down or

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Speaker 1: works in properly. However, the technology available to scientists today

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Speaker 1: does not provide cellular level information. The process is currently

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Speaker 1: being researched, but whether scientists can explain it or not.

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Speaker 1: Mental fatigue feels real when you have it. When mental challenges,

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Speaker 1: whether it's work, today's political climate, or just the fast

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Speaker 1: pace of modern life, are constantly coming at you, your

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Speaker 1: stress response can keep getting switched on. This can prompt

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Speaker 1: your body to release a lot of the stress hormone cortisol.

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Speaker 1: Greenberg explained that our stress response isn't meant to be

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Speaker 1: on all the time, and that this is what can

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Speaker 1: lead to burnout, which she describes as dealing with so

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Speaker 1: many problems or things that don't have solutions. This kind

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Speaker 1: of mental and emotional fatigue from over stress can affect

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Speaker 1: your immune system and interview with concentration, memory, and focus.

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Speaker 1: The good news is that you can avoid mental burnout.

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Speaker 1: Just knowing that there are limits to your brain function

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Speaker 1: glucose or not, will help you think differently. The prefrontal cortex,

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Speaker 1: where your higher order thinking is done, takes a lot

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Speaker 1: of energy, so your brain can't perform complex tasks all day,

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Speaker 1: so consider completing your most challenging activities in the morning.

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Speaker 1: Keeping a healthy diet and lifestyle helps here too. Getting

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Speaker 1: enough sleep, getting exercise, not being too hard on yourself,

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Speaker 1: and not being a perfectionist. Your brain can only do

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Speaker 1: so much until science finds out more about the interworkings

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Speaker 1: of brain cells. To help them do more, you'll have

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Speaker 1: to focus on lifestyle changes, and there are a lot

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Speaker 1: of different techniques to help you manage your stress. A

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Speaker 1: bit of research online can turn up many different things

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Speaker 1: to try until you find something that works for you. However,

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Speaker 1: if you're experiencing mental fatigue and don't have a clear

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Speaker 1: cause for why, particularly like a hard day at the

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Speaker 1: office or a tough French exam, Fegale recommends checking for

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Speaker 1: a medical issue. Because people are affected differently cognitively just

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Speaker 1: as they are physically. Changes in your usual cognitive emotions

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Speaker 1: should raise a red flag. You don't even have to

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Speaker 1: see a specialist. Your regular doctor can give you some

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Speaker 1: recommendations to go on. Today's episode was written by Carrie Whitney,

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Speaker 1: PhD and produced by Tyler Clang. Brain Stuff is a

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Speaker 1: production of I Heart Radio's How Stuff Works. For more

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Speaker 1: on this and months of other brainy topics, visit our

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Speaker 1: home planet how stuff Works dot com, and for more

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