Learners report increased cravings for literal food while their brains binge on new intellectual material, a recent poll suggests. Could "starving student" mean something beyond the limited finances of full-time study?
Beyond the Uni-years, do race-paced brains get Hangry? If we are competing in a purely intellectual 'ultra' do we need day-glow fluids to keep us from hitting that wall?
The adult brain is about 2% of the body weight. yet, uses around 20% of the oxygen and calories consumed by the body (1).
This high rate of metabolism is remarkably constant
despite widely varying mental and motoric activity...
[and is] remarkably constant over time." (10)
Scientifically quantifying the metabolic needs of intellectual exertion has been tricky. Try writing about it! But, "...in most cases, short periods of additional mental effort [spikes] require a little more brainpower than usual, but not much more. “(6)
"Some studies have found that when people are not very good at a particular task, they exert more mental effort and use more glucose. Llikewise, the more skilled you are, the more efficient your brain is and the less glucose you need. " (7,6)
Some studies showed that “more skillful brains recruit more energy” (7), but... there's a catch.
Attitude is Everything
“….Equally important to the duration of mental exertion is one's attitude toward it.” (6,8)
"A small but revealing study suggests that even mildly stressful intellectual challenges change our emotional states and behaviors, even if they do not profoundly alter brain metabolism." (9)
When called to action by stress, our adrenal glands take over, then dump us, leaving behind a wake of hangry caloric cravings. It is then that metabolism increases beyond the otherwise steady rate of brain consumption.
What is more, "... something must explain the feeling of mental exhaustion, even if its physiology differs from physical fatigue. Simply believing that our brains have expended a lot of effort might be enough to make us lethargic…" (11)
Brain Vs. Brawn
We've been focusing on one narrow part of fuel consumption under the strain of brawn or brain: calories But your brain is more than a just a muscle [car]. Let's consider a broader scope of smart consumption.
Pretend your brain is a turbo-injected diesel SmartCar that is modified with a Prius-ish battery loop inside, which feeds torque, electrically. The result: a darty little hybrid in which fuel metabolism connects with battery exchange. Now, unleash this diesel-conserving dynamo in an endurance race, on a stress-free track (13). Brain blitzes brawn.
The diesel performs fairly steadily, just as brain metabolism stays within a pretty constant range of gylcogen needs, even during cognitive spikes. In times of trouble, there are tiny turbo injections. Plus, this little modified Smartie electrically torques it's baby-brawn through stop-start tasks, thus economizing fuel consumption.
"The brain is not just mechanical consumer of fuel.
It's an electrical powerhouse
Hangry Electrical Circuits
Bazillions of neuron "connections" extend from the brain in order to light up, well, everything.
Neurons have different levels of hunger: "…bigger neurons have higher overall consumption than small ones, ...but also, different neurons have different energy distributions… "(12)
Scientists have tried to "estimate the energy needed for signaling between two neurons...[data shows that]… for most neurons, this inter-neuronal communication--called “synaptic transmission”--actually takes up more energy than spiking" (12).
"In fact, there are many tasks within neurons that each require a different share of energy, including not only spiking and talking to other neurons, but also maintaining stores and generating new signaling molecules."(12)
Recall that spikes don't really affect brain metabolism of glycogen all that drastically. This chart shows that, of the energy gobbled up by the cortex, spiking only accounts for 21%.
What else effects brain metabolism? Other than regulating the stress effects on glycogen consumpton,
let's not overlook the electrical works behind thinking.
Smart Fuel "Additives"
The Budget above shows that 79% of the cortex's operations involve ions and electrolytes. Neurons throughout the body and brain gobble ions. Electrolytes are the chemicals from which ions are made. Electrolytes like sodium, potassium and magnesium, charge the entire nervous system.
"Sodium electrolytes, made by dissolving salt in fluid,….gives the inside of the nerve cell an electrical charge, settling off an electrochemical nerve impulse,…Without sodium, you brain cannot initiate the electrical impulses your nerve cells require for proper communication. (1)
"…After sodium rushes into the nerve cell, potassium electrolytes …allowing the cell to re-establish its resting state. Without adequate potassium, a nerve cell cannot send more than one electrochemical impulse (1)".
Magnesium "helps control the flow of sodium and potassium into and out of your nerve cells. Magnesium also [helps the sheath around the]…nerve cells [that improves]… transmission of electrochemical signals" (1) Magnesium economizes nerve transmission.
Electrolyte access during intellectual feats
may help recharge and hydrate our hangry little brain.
(Drinking lots of water is not the same as actually absorbing it!)
Recognizing "Hanger"... is the First Step in Recovery
Bonking is an indicator that we have failed our brain, not that it has failed us. The brain is often overlooked, despite all it's granted expectations. Lapse in performance, during intellectual challenges, may indicate that we have missed refuelling ourselves.
Create healthy rewards for your thinking powerhouse:
Use mindfullness tools before bouts of pressured study, in order to pre-empt the stressors that will burn out your glycogen.
Schedule short, truly restorative breaks from brain or endurance activities. Sorrrry: stimulants, sugar, or adrenal-pumping exercise are not restorative.
Time these breaks following brain "spikes" like: deep focus on challenging subjects that you are unskilled at, subject hopping etc.
Break up brain spikes with skilled subjects: reprieves from stress or anxiety. Coast pleasantly while keeping some momentum.
Use a timer to economize spiking and coasting periods, mindful breaks and snacks.
Ensure your daily diet includes healthy fats, so that you become an efficient converter of "brain diesel". Don't depend on sugar or glucose.
Make sure that your mineral consumption is excellent, and that your body has steady access to electrolytes to optimize water absorption.
The brain burns brighter with oxygen. Open a window and breathe!
Prevent Hitting the Wall with awareness, planning and clean fuels.
If you're an endurance athlete, in addition to an intellectual one, take extra care to avoid brain "shrinkage"! (See "Hangry for Brain-Aids 1.0: Endurance Athletes" by Låna Brown.)
©️2017 Lana Brown, written content..
Reference citings below. Input from researchers & specialists in human sciences appreciated.
(1) Tremblay, Sylvie. MSc.. Electrolytes & the Brain. Retrieved from: http://healthyeating.sfgate.com/electrolytes-brain-2895.html)
(2) Noakes, Timothy D. MB ChB, MD. (Sept 2000). Hyponatremia in Distance Athletes - Pulling the IV on the ‘Dehydration Myth’. The Physician and Sportsmedicine. Vol. 28 - No. 9. Retrieved from journal URL: http://www.physsportsmed.com/issues/2000/09_00/
(3) Sheard, Erin. (Apr 2010). Can your brain hit the wall? Retrieved from journal URL: http://www.irun.ca/issues/article.php?id=238&intissueID=15
(4) Davis, Mark J., Central Nervous System Fatigue. Retrieved from journal: Latta, Sara (2003). The Wall. URL: http://marathonandbeyond.com/choices/latta.htm
(5) Dr. Maffetone, Phil. (April 30, 2015) Beat the Bonk with your Brain: an exerpt from “The Big Book of Endurance Training and Racing”. Retrieved from URL: https://philmaffetone.com/beat-the-bonk
(6) Ferris, Jabr. (July 18, 2012). Does Thinking Really Hard Burn More Calories?. Scientific American. Retrieved from journal URL: https://www.scientificamerican.com/article/thinking-hard-calories/
(7) Larsen, Gerald E, et al., (Nov-Dec 1995). Evaluation of a “mental effort” hypothesis for correlations between cortical metabolism and intelligence. Intelligence. Vol. 21, Iss. 3. Retrieved from journal URL: http://www.sciencedirect.com/science/article/pii/0160289695900179
(8) Messier, Claude. Glucose improvement of memory: a review. European Journal of Pharmacology. Retrieved from journal URL: http://www.sciencedirect.com/science/article/pii/S0014299904002006
(9) Chaput JP, et al., (2008 Sep) Glycemic instability and spontaneous energy intake: association with knowledge-based work. 70(7):797-804. DOI: 10.1097/PSY.0b013e31818426fa. Epub 2008 Aug 25. Retrieved from journal URL: https://www.ncbi.nim.nih.gov/pub-med/18725427
(10) Raichle, Marcus E and Gusnard, Debra A. Appraising the Brain’a Energy Budget. Retrieved from journal URL: http://www.pnas.org/content/99/16/10237.full
(11) Ferris, Jabr. (July 18, 2012). Does Thinking Really Hard Burn More Calories?. Scientific American. Retrieved from journal URL: https://www.scientificamerican.com/article/thinking-hard-calories/
(12) Lee, Ada of Neuwrite West Blog. (May 28, 2014).Does the brain have an energy budget? Under duress: How the Brian Conserves Energy. Stanford Neurosciences Institute: Ask a Neuroscientist. Retrieved from journal URL: https: neuroscience.stanford.edu/news/ask-neuroscientist-does-brain-have-energy-budget
(13) Photo credit: http://www.roadandtrack.com/car-culture/videos/a8015/smart-car-wheel-stand/
First published Mar 22/17