He had a long and distinguished career on the track in the 110 meter high hurdles, winning his first Olympicgold medal in the 1984 Summer Olympics. In 1988, he was unbeaten all season and was the favorite to retain his Olympic title in the 1988 Summer Olympics in Seoul, South Korea. In a stunning display of technique, power, and speed, he won by three meters, becoming the first man to run below the 13 second barrier in an Olympic final, running 12.98s. This record stood until 1996 when Allen Johnson broke it at the Atlanta Games. Kingdom is only the second athlete to have successfully defended his 110 m hurdle Olympic title, after Lee Calhoun, who won the gold medal in both 1956 and 1960.
On March 6, 2014, Kingdom was hired as the assistant strength and conditioning coach for the NFL's Arizona Cardinals. Kingdom worked with head strength and conditioning coach Buddy Morris, his own strength coach at the University of Pittsburgh, and focused on improving the team's speed.[2]
Kingdom then spent the 2018 season as the Interim Director of Track & Field/Cross Country at the University of Central Florida
In 2019, Kingdom returned to the NFL as the speed and conditioning coach of the Tampa Bay Buccaneers. In Tampa, he again worked under head coach Bruce Arians, who was the Cardinals' head coach during Kingdom's tenure in Arizona.[3]