Mullings has a twin sister Kennedi and a brother Aaron. His mother Eulease is an accounts clerk. Mullings attended CC Sweeting High School before going on to study at the University of the Bahamas.[2]
He set a personal best decathlon points tally of 7,734 on June 27, 2021 at Thomas A Robinson National Stadium. The following year, he finished in 17th place overall in the men’s decathlon at the 2022 World Athletics Championships in Eugene, Oregon with a total of 7,866 points.[6] He also won the NACAC (North American, Central American and Caribbean Athletic Association) Combined Events Area Championships, scoring 7,537 combined points at the Terry Fox Athletic Facility in Ottawa, Canada, in 2022.[7]
Mullings competed at the 2023 Pan American Games in Chile, in the decathlon.[8] He set a new decathlon PB of 8,060 in 2023. In a heptathlon in Illinois at the end of January 2024, Mullings set PBs in six of the seven disciplines, winning with a national record of 6340. That month he also set a new national record for the pole vault, in Illinois.[9][10]