You may wonder if the act of thinking burns more calories than mindless activities like watching television. Yes, but only to a certain extent.

After a long day at work or school, it’s common to feel tired. This is especially true if you do a lot of mental tasks, which can zap your physical energy.

In turn, you may wonder if the act of thinking burns more calories than mindless activities like watching television. After all, if you’re tired after thinking, doesn’t that mean you’re burning energy?

Yes, but only to a certain extent. Although thinking hard uses calories, the energy burn is minimal. It’s not enough to burn fat and cause weight loss.

The brain is also an organ, not a muscle. Exercise can grow your muscles, which makes them burn more calories. This concept doesn’t apply to the brain.

Still, working out your brain has other benefits. It can boost cognitive functions like memory and focus, and slow down cognitive decline.

To learn how thinking affects your calorie burn, read on.

First, it’s important to understand how your body uses calories.

You burn energy even when you’re sedentary. For example, as you read this article, your body is using calories to support:

  • breathing
  • blood flow
  • body temperature
  • digestion

Your brain also uses energy to perform normal functions. Although it makes up 2 percent of your body weight, it burns 20 percent of the energy you consume. This metabolic activity is generally consistent, regardless of what you’re doing.

In fact, your brain burns more energy at rest than a human thigh while running.

Specifically, your brain gets energy from glucose. Glucose comes from the food you eat. The glucose enters your bloodstream, then travels to your brain.

Here, it’s used to make adenosine triphosphate (ATP), a form of energy. Your nerve cells need ATP to communicate and carry out cognitive tasks.

When you mentally exert yourself, your brain uses more energy to do the task. But it’s not much more than normal brain activities.

Though thinking burns calories, it’s not enough to cause weight loss. The increase in calorie burn is small.

You need to burn 3,500 calories to lose 1 pound. In 1 week, this equals out to 500 calories a day.

If you were to solely depend on mental tasks, you’d need to exert yourself for many hours.

For example, as mentioned earlier, a 155-pound person burns about 42 calories in 30 minutes of reading. This person would have to read for almost 6 hours to burn 500 calories in a day.

Granted, occasionally moving around will increase calorie burn per hour. But it still wouldn’t be enough to cause weight loss.

It’s still beneficial to work out your brain. Examples of brain exercises and their benefits include:

  • Brain teasers. A 2013 study found that brain-training games boost executive functions and memory in healthy young adults. Brain puzzles, like Sudoku or crossword puzzles, can challenge your brain.
  • Learning something new. Reading, learning a new hobby, or watching documentaries can keep your brain active.
  • Playing or listening to music. According to a 2013 article, these activities help boost memory and executive function.
  • Socializing. Maintaining healthy social relationships can support cognitive performance, according to a 2017 study. Consider joining a book club, fitness class, or volunteer group.
  • Regular exercise. Physical activities like walking or gardening are beneficial for your body and brain. In a 2018 study, researchers found that aerobic exercise can support neuronal health and cognitive function.

All brain workouts are not equal, though. It’s important to continuously challenge yourself. If you frequently repeat the same activities, your brain won’t be as active.

Also, it’s a myth that age-related cognitive decline is inevitable. According to a 2015 article, lifestyle factors can protect and boost brain function. This includes the activities above, along with eating well and avoiding smoking.

It’s normal to feel tired after going to the gym. Likewise, it’s typical to get tired after work or school, but it’s not the same thing.

Glucose is stored as glycogen in your muscles. When you exercise, your muscles break down glycogen and use glucose to move.

Eventually, your muscles run out of energy and you feel tired. It also becomes difficult for your central nervous system to contract your muscles. The result is physical fatigue.

Mental activity also uses glucose, but it doesn’t require your muscles to break down glycogen. Instead, it causes mental exhaustion, which increases your perceived exertion of physical tasks, according to a 2017 review.

To increase your calorie burn, do exercises that involve your biggest muscles.

Larger muscles require more energy to move. Some of your largest muscles include:

Your brain burns calories to perform basic functions. It burns a bit more if you think really hard, but it’s not enough to make you lose weight.

That doesn’t mean exercising your brain has no benefits. Activities like listening to music, doing puzzles, and learning new hobbies can all boost your cognitive function.

If you want to burn more calories, focus on exercise and healthy eating. Exercising your largest muscles, like your glutes and biceps, will increase your calorie burn.