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:
“...here he is, fully alive, and it is hard to picture him fully dead. Death is thirty-three hours away and here we are talking about the brain size of birds and bloodhounds and hunting in the woods. You can only attend to death for so long before the life force sucks you right in again.”
—Helen Prejean (b. 1940)
“Shall quips and sentences and these paper bullets of the brain awe a man from the career of his humor? No, the world must be peopled.”
—William Shakespeare (1564–1616)
“She turns and looks a moment in the glass,
Hardly aware of her departed lover;
Her brain allows one half-formed thought to pass:
“Well now that’s done: and I’m glad it’s over.””
—T.S. (Thomas Stearns)