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:
“I consider that a man’s brain originally is like a little empty attic, and you have to stock it with such furniture as you choose.”
—Sir Arthur Conan Doyle (1859–1930)
“My brain is dull, my sight is foul,
I cannot write a verse, or read—
Then, Pallas, take away thine Owl,
And let us have a lark instead.”
—Thomas Hood (1799–1845)
“I could brain him with his lady’s fan.”
—William Shakespeare (1564–1616)