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)
“If they’ve a brain and cerebellum, too,
They’ve got to leave that brain outside,
And vote just as their leaders tell ‘em to.”
—Sir William Schwenck Gilbert (1836–1911)
“Always in England if you had the type of brain that was capable of understanding T.S. Eliot’s poetry or Kant’s logic, you could be sure of finding large numbers of people who would hate you violently.”
—D.J. Taylor (b. 1960)