Brain Energy

[Guest John Akin]

1) I'm told that our brains use 20% of our body's energy.

Is this constant? In other words do we use more energy when we are in a stressful situation and less when relaxed?

2) What is the relationship between brain energy demand and temperature?

 

John A

[Frostrunner]

Well, I know that the more active a part of the brain is it uses more energy. This is how an FMRI (Functional Magnetic resonance Imaging) works. In short, It senses where the oxygen is being metabolized. For more info on it google would be by best bet. Synapse firing does take energy. As far as stressed and relaxed it is hard to say. It depends on the amount and place of the brain is being "used" at the moment. As a side note this is how they found that the brain is active during sleep, long ago they found that the brain is as active (sometimes more) during sleep.

 

I am just thinking of other paradigns and it makes sense that the more active a brain is the higher the temp will be. However, this is well within the range of the bodies cooling abilities. Also think the blood around the head is fairly open to the surface for cooling; e.g. neck and ears. There are instances were the brian does run into problems. This is why you rush a person to the hospital if their fever get to be over 104 F since that is when brain cells start to overheat. Sometimes people say that when this is happening they start to hallucinate due to the brain damage (not sure on the specifics). Also swelling can occur and this can cause major problems.

[Guest John Akin]

Thanks for the reply.

Do you think it is possible to enhance sporting endurance by conserving brain energy? If mental techniques (relaxation, etc) can be used to lessen the intensity of thought, will brain energy demand decrease thus allowing more of our body's stored energy to be utilised for physical performance?

I would expect that even a small decraese in brain-energy demand, say from 20% to 19%, would be significant to runners, cyclists, etc.

[Frostrunner]

I wouldn't really consider the fact of lessening brain energy demand that does not sound wise, but I commend you on thinking outside the box.

 

Actually there are some studies out there (haven't personally read them) that say that for sports it is best to try to clear the mind due to the fact that by consciously thinking about doing something it takes longer than a reflex action. Thus it is quicker to relax and reflexively catch a ball than it is to think consciously about catching it (like trying to project where it will go). There are also some studies where the participants ran fast when they thought about there muscles moving and the specific mechanics (CORRELATION not CAUSATION WARNING: this cannot be disassociated though with thier technique improving due to the thoughts). I would take both of these studies with a large grain of salt though. Test it out for yourself, go to a track run then meditate and run.

There are alot of studies about medittation in sports one of the more interesting ones is where they tried to see if injured athletes would heal quicker with meditation and then focusing that on their injury. It did seem to help but it wasn't a "good" study since inorder for a control you would have to injure the athlete in the same place a second time and go without meditation. I don't think that that would be a good idea. The overall claim was that through meditation you stimulate the "mind" to tell the body to send more white blood cells and to stimulate the healing process. Also stress lowers the immune system (that is truely proven) and thus relaxing could help it. Hey, if you are just going for an outcome not proving HOW it works correlation is a good enough reason to try it. If Monks can alter there body temperatures then there is probably alot that the "mind" can do that we are just now getting around to studying.