According to an article in Popular Science, the human brain burns 1/10th of a calorie per minute just staying alive; 10 minutes equals 1 calorie. No, not the way to lose a lot of weight, but it is kind of a fun fact. Walking burns about four calories a minute, while kickboxing burns a whopping 10 calories a minute. Still, both of these activities can cause a sweat. Did you know, though, that just reading my blog burns off a "respectable" 1.5 calories per minute. Can you feel the burn?
You might not be too impressed with that 1.5 calories per minute but take into consideration that your brain only accounts for 2% of your body mass. What this means is that over the course of your day, this one organ uses 20% or 300 of the 1300 calories the average person needs each day just to function. So, you might ask, where do those calories go?
"It's not all to your gray matter. Here's how it works: The brain is comprised of neurons, cells which communicate with other neurons and transmit messages to and from body tissues. Neurons produce chemicals called neurotransmitters to relay their signals. To produce neurotransmitters, neurons extract 75% of the sugar glucose (available calories) and 20% of the oxygen from the blood. PET scans have revealed your brain doesn't burn energy uniformly. The frontal lobe of your brain is where your thinking takes place, so if you are pondering life's big questions, like what to have for lunch to replace the calories you are burning, that part of your brain will need more glucose"
Being a "mathlete" or an avid reader won't get you physically fit; you still need to work your muscle groups to get toned and lean. But, contemplating your navel or other deep thoughts will, in fact, burn 20-50 more calories each day than just laying by the pool and snoozing.
Is there such a thing as mental fatigue...something akin to what we experience physically after a good workout? Certainly! Students regularly report "mental exhaustion" after taking intensive exams such as SAT (Scholastic Aptitude Test) or MCAT (Medical College Admissions Test). The physical toll is real but it is a combination of both stress AND concentration. If you think a lot for a living, or just enjoy thinking as a recreational activity, you'll be pleased to know that thinkers become more "efficient as using energy." We give our brains a real workout whenever we focus our attention on difficult or unfamiliar tasks. If you've ever experienced neurofeedback, you know what I mean. After a 15-20 minute brain-training session, clients report feeling tired even though all they've done is play a video game or watch part of a movie. Why? It's because the brain is receiving a workout by being trained (rewarded) to do something it's not used to.
Scientists have also studied the effects of sugar and other carbohydrates on the human body and brain. One study showed that simply rinsing your mouth with a carbohydrate solution can activate those parts of the brain that enhance exercise performance. Does the effect also improve mental performance? There is a lot of conflicting theories. There is evidence, however, that carbohydrates (not necessarily sugar) can improve mental function. What this means is that if you are facing a tough mental challenge and don't feel "up to the task," there's good chance that a snack might help.
Okay, so maybe I didn't find a way to burn calories and DO nothing but read or think, but it's good to know that these activities do help burn a few extra calories. Twenty to fifty calories a day is a lot for a frog...maybe not so much for humans, though.
Whatever your weekend plans include, have a little fun and please stay safe. And remember to use your sunscreen if you're spending time outdoors. I hope to see you all back here on Monday.