Olympic gold medalist Michael Phelps has broken his own U.S. short course record in the 200 yard butterfly at the Maryland Swim Championships at the U.S. Naval Academy.

Phelps, who won both the 2004 and 2008 Olympic gold medal in the 200 meter butterfly, had a time of 1:39.65. His old U.S. record of 1:39.70 in the 200-yard event was set March 3, 2006 at the South Texas American Short Course Championships.

The Naval Academy pool is measured in yards, not meters. The record is considered unofficial until it is certified by USA Swimming.

It was the third win of the weekend for Phelps, who was swimming competitively for the first time in seven weeks.

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