(CNN) Dalilah Muhammad shattered a 16-year-old record in 400 meter hurdles at the USA Track and Field Outdoor Championships in Iowa Sunday.

Muhammad, an Olympic gold medalist, finished the race with a time of 52.20 seconds, according to the International Association of Athletics Federations (IAAF). She was 0.14 seconds faster than the previous record set in 2003 by Yuliya Pechonkina, the IAAF said.

Muhammad's record is pending, though, because of ratification procedures to confirm the record was officially broken, the IAAF said.