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Have you ever thought why thinking makes
tired? A new study has found some
. Researchers from the Paris Brain Institute looked at why
effort makes us tired. When people think a
, their brain releases a chemical called glutamate. Too much of this changes the brain's
. It tells the body it is
and that we must rest. People who spend six hours working on a
that requires thinking are more likely to feel tired. Resting helps the brain to return to
. This explains why a power nap is
for us. A 20-minute power nap can make us feel
refreshed.
