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Have you ever wondered why thinking too
makes you tired? A new study has found out
answers to this question. Researchers from the Paris Brain Institute looked at why
effort makes us tired. They found that when people think a
, the brain releases a chemical called glutamate. Too much glutamate upsets the brain's
. It means the brain tells the body it is
and that it must rest. People who spend more than six hours working on a task that requires a lot of
are more likely to feel tired. A period of rest allows the brain to return to
. This explains why a power nap is good for us. A power
can be as short as 20 minutes, but can make us feel
refreshed.
