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:
“We talk about a representative government; but what a monster of a government is that where the noblest faculties of the mind, and the whole heart, are not represented! A semihuman tiger or ox, stalking over the earth, with its heart taken out and the top of its brain shot away. Heroes have fought well on their stumps when their legs were shot off, but I never heard of any good done by such a government as that.”
—Henry David Thoreau (1817–1862)
“Nature, we are starting to realize, is every bit as important as nurture. Genetic influences, brain chemistry, and neurological development contribute strongly to who we are as children and what we become as adults. For example, tendencies to excessive worrying or timidity, leadership qualities, risk taking, obedience to authority, all appear to have a constitutional aspect.”
—Stanley Turecki (20th century)
“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)