Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, Lauren fog Bomb here. We've all felt it, the mental fatigue after working a long day, taking finals, or running errands all over town. That tired, dull feeling like the hinges on your brain are rusty and they creak and grown if you try to recall something or pay attention. When this type of brain drain sets in, regardless of how hard you try to concentrate, you probably find yourself
exhausted and unable to fully focus. Is this kind of mental fatigue evidence that you've overworked your brain? Does your brain actually get tired in the same way that your muscles do? And is there any difference between mental fatigue and good old physical exhaustion and is there any way to prevent it? Of course, your brain isn't a muscle. It does have a bit of muscle tissue, but it's
mostly made up of fat. In the brain, electric cells called neurons transmit messages via chemicals, and although the brain isn't muscle, it cells do use energy to function. The sugar molecule glucose is the brain's primary source of that energy. When glucose enters the brain, cells organelles called mitochondria convert the glucose into a dentisine triphosphate, or a t P, which is a complex organic chemical for storing and transferring
energy in cells. A group of researchers from Australia and Belgium thought that the compound a TP could be the key to brain drain. The idea was that when your brain works hard, it uses up all that glucose, leaving you feeling depleted. The lower glucose levels then raise levels of a t P, which blocks dopamine, that chemical that
makes you feel good and keeps you motivated. The study, which was published in the journal Sports Medicine, concluded that when your brain can't get enough dopamine, you're less likely to stay on task. So even though your brain isn't a muscle chemically, you can tire it out by thinking too much. We spoke with Melanie Greenberg, pH d, a clinical psychologist in the Bay Area of California and author
of a book called The Stress Proof Brain. She explained that humans aren't wired to do complex types of thinking all the time. These executive functions are higher level cognitive skills that let you monitor your goals and process information
in order to execute plans to achieve those goals. These can include obviously challenging tasks like taking the l s at, but can also comprise a combination of smaller challenges, like meeting new people or navigating a route you're unfamiliar with, or even resisting impulses like having another cookie or skiving off work. Greenberg said, after a while, our brains automate
things and take less energy. For example, if you drive the same way to work every day, that activity will use less brain energy than if you had to constantly find new roots. When your brain is dealing with an ongoing supply of new information, it must put energy into every decision, which overuses that executive function and can cause mental fatigue. All using up available glucose in your brain creates mental fatigue. Simply taking in more glucose won't fully
and immediately recharge your brain. Eating a snack to provide glucose or having a coffee to up your dopamine can help, but neither will eliminate the brain drain because the cellular functions are more complicated than that. We also spoke with Gary Fegale, m D, a geriatric psychiatrist in Atlanta, who specializes in neurology and psychiatry. He explained that every brain cell is connected to a hundred thousand other cells in a highly integrated network, and when you're tired, your brain
has decreased blood flow and electrical activity. Scientists are still in a hypothetical stage of understanding the brain, meaning they're making a lot of educated guesses about how it works. They know that rest is important, but they still aren't sure why it's important to our brains. But Figel said that if you simplify, you can say that there are four steps to a well functioning brain. Glucose must be available in the blood, Glucose must be efficiently transported inside
the cells. A glucose must turn the mitochondria, and the mitochondria must produce a t P. Thus, a breakdown in any of the four steps can be to blame for mental fatigue. So, for example, even if glucose is available, fatigue might happen when a cellular function slows down or works in properly. However, the technology available to scientists today does not provide cellular level information. The process is currently being researched, but whether scientists can explain it or not.
Mental fatigue feels real when you have it. When mental challenges, whether it's work, today's political climate, or just the fast pace of modern life, are constantly coming at you, your stress response can keep getting switched on. This can prompt your body to release a lot of the stress hormone cortisol. Greenberg explained that our stress response isn't meant to be on all the time, and that this is what can lead to burnout, which she describes as dealing with so
many problems or things that don't have solutions. This kind of mental and emotional fatigue from over stress can affect your immune system and interview with concentration, memory, and focus. The good news is that you can avoid mental burnout. Just knowing that there are limits to your brain function
glucose or not, will help you think differently. The prefrontal cortex, where your higher order thinking is done, takes a lot of energy, so your brain can't perform complex tasks all day, so consider completing your most challenging activities in the morning. Keeping a healthy diet and lifestyle helps here too. Getting enough sleep, getting exercise, not being too hard on yourself, and not being a perfectionist. Your brain can only do so much until science finds out more about the interworkings
of brain cells. To help them do more, you'll have to focus on lifestyle changes, and there are a lot of different techniques to help you manage your stress. A bit of research online can turn up many different things to try until you find something that works for you. However, if you're experiencing mental fatigue and don't have a clear cause for why, particularly like a hard day at the office or a tough French exam, Fegale recommends checking for
a medical issue. Because people are affected differently cognitively just as they are physically. Changes in your usual cognitive emotions should raise a red flag. You don't even have to see a specialist. Your regular doctor can give you some recommendations to go on. Today's episode was written by Carrie Whitney, PhD and produced by Tyler Clang. Brain Stuff is a
production of I Heart Radio's How Stuff Works. For more on this and months of other brainy topics, visit our home planet how stuff Works dot com, and for more podcasts for my heart Radio, visit i heart Radio app, Apple Podcasts, or where every listen to your favorite shows