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:
“You are as still as a yardstick. You have a doll’s kiss.
The brain whirls in a fit. The brain is not evident.
I have gone to that same place without a germ or a stroke.
A little solo act that lady with the brain that broke.”
—Anne Sexton (1928–1974)
“When the situation is, what we would wish, nothing is so ill- timed as to hint at the circumstances which make it so: you thank Fortune ... you had reason—the heart knew it, and was satisfied; and who but an English philosopher would have sent notices of it to the brain to reverse the judgment?”
—Laurence Sterne (1713–1768)
“Invention flags, his brain goes muddy,
And black despair succeeds brown study.”
—William Congreve (1670–1729)