Brain
At rest, the human brain receives 15% of total cardiac output, and uses 20% of the body's energy consumption. The brain is normally dependent for its high energy expenditure upon aerobic metabolism. The brain as a result is highly sensitive to failure of its oxygen supply with loss of consciousness occurring within six to seven seconds, with its EEG going flat in 23 seconds. If it affected the oxygen and glucose supply to the brain, the metabolic demands of exercise could therefore quickly disrupt its functioning.
Protecting the brain from even minor disruption is important since exercise depends upon motor control, and particularly, because humans are bipeds, the motor control needed for keeping balance. Indeed, for this reason, brain energy consumption is increased during intense physical exercise due to the demands in the motor cognition needed to control the body.
Read more about this topic: Exercise Physiology
Famous quotes containing the word brain:
“My own brain is to me the most unaccountable of machinery—always buzzing, humming, soaring roaring diving, and then buried in mud. And why? What’s this passion for?”
—Virginia Woolf (1882–1941)
“When our brain feels too weak to deal with our opponent’s objections, our heart answers by casting suspicion on their underlying motives.”
—Friedrich Nietzsche (1844–1900)
“I think “taste” is a social concept and not an artistic one. I’m willing to show good taste, if I can, in somebody else’s living room, but our reading life is too short for a writer to be in any way polite. Since his words enter into another’s brain in silence and intimacy, he should be as honest and explicit as we are with ourselves.”
—John Updike (b. 1932)