It's the equivalent of putting on the brakes suddenly while driving uphill.
Source: On writing magazine articles to pay the travel expenses engendered by writing books, in Saturday Review, 13 Dec 1962.
-- John Gunther, (Aug 30 1901-1970), US journalist; He became famous for his series of sociopolitical books describing Inside Europe, 1936; also wrote Death Be Not Proud, 1949.