Originally Posted by
chucky
Is it the loss of glycogen that causes the kidneys to shut down or is it the sheer trauma of pounding the pavement? I ran a marathon 3 weeks ago without any training and, though I felt like I had plenty of energy, it was one of the most punishing experiences of my life. Also, it was my understanding that weight gain and brain swelling was the result of overhydration (ie drinking fluids even after your kidneys have taken a siesta)...after all how can you gain weight if you stop consuming?
What say you bluefoxicy?
http://www.amaasportsmed.org/news_ro...ia_reuters.htm
He found that they died, not just from drinking too much water, but because their kidneys stopped excreting water as a response to skeletal muscle injury.
When runners "hit the wall" they force their muscles to continue to exercise even after they've run out of glycogen, or fuel, he told Reuters Health in an interview. This triggers a stress hormone in the brain to tell the kidneys to halt water excretion, in an effort to maximize blood volume.
When this happens, even a relatively small amount of fluid can cause the brain to swell. If a person continues to consume fluids, the body reacts to the inflammation by continuing to protect blood volume, making the brain swell even more.
You lose sodium, you drink water, you die from water intoxication. Drinking too much water.
You lose sodium, your kidneys push water to your bladder and lymph system to keep things in homeostasis.
You lose sodium, you overexert yourself, your kidneys stop pushing water to your bladder and lymph system, suddenly even small amounts of water intake will kill you.