After a stroke, far too much glutamate is released, overworking nearby brain cells until they expire.

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Overworking is one of the most negative behaviors that companies promote and reward in Silicon Valley.

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Some cramps are associated with overworking the muscles, dehydration or staying too long in one position.

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Overworking is not caused by the workplace any more than alcoholism is caused by the liquor store.

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Thirty-nine percent said more than five hours every week, 35% said two to five hours a week and 13% said they spent less than one hour a week overworking.

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Speaking on his own programme, BBC Two's Andrew Marr Show, he said he had been "heavily overworking" in the year before the stroke, which was sparked by an intensive rowing machine session.

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