[5] Cox was an accomplished freestyle wrestler growing up, claiming multiple US National Championships, despite never competing overseas.

[6] In 2014, the newly crowned freshman NCAA champion at 197 pounds, decided to compete at 97 kilograms (214 pounds) despite being undersized for the weight class, and made his senior level debut by placing third at the US University National Championships, and later in the month competing at the US World Team Trials, but failing to place.

[10][11] In 2015, he placed fourth at the US Senior Nationals, falling to eventual 2015 World Champion Kyle Snyder by one point throughout the bracket.

[12] As a 2016 NCAA champion, Cox qualified to compete at the 2016 US Olympic Team Trials, and chose to trim down to 86 kilograms.

[14] There, he defeated four–time NCAA champion Kyle Dake, who was bumping up from 74 kilograms, two matches to one to claim the 2016 US Olympic Team spot.

[17] After defeating '12 University World Champion from Iran Meisam Mostafa-Jokar at Beat the Streets,[18] Cox competed for Team USA at the 2016 World Cup, beating two–time Commonwealth champion Pawan Kumar, returning World Championship bronze medalist from Iran Alireza Karimi and 2016 European Championship runner–up Aleksander Gostiev, before being defeated himself by '12 Olympic bronze medalist from Georgia Dato Marsagishvili, helping Team USA reach fourth place.

[20] At the Summer Olympics, Cox claimed victories over Amarhajy Mahamedau and Alireza Karimi before suffering a loss to '09 Junior World Champion Selim Yaşar in the semifinals, getting knocked off to the consolation bracket, where he posted a victory over reigning Pan American Games champion Reineris Salas, in a match were the Cuban refused to continue after suffering a takedown from Cox.

[23] After losing the first match, Cox rallied to defeat Taylor twice in a row despite a knee injury to retain the spot, although controversially due to his excessive sweat and alleged passivity.

[25][26] Cox made his return by moving up to 92 kilograms in February 2018, claiming a silver medal from the Ukrainian Open after losing to World and Olympic champion Sharif Sharifov in the finale.

[31] Despite his low international success at the new weight class earlier in the year, Cox went on to claim his first World Championship for the United States, defeating two–time European Continental champion from Georgia Dato Marsagishvili, three–time Olympian from Moldova Nicolai Ceban, '18 Asian Games gold medalist from Iran Alireza Karimi and '16 European Championship runner–up from Belarus Ivan Yankouski.

[32] The returning World Champion, Cox claimed his first Pan American Continental Championship in his first tournament of the year, helping the US reach gold in all of the 10 freestyle categories in the competition.

In his first tournament, he most notably downed '15 Pan American Games champion (86kg) Reineris Salas and returning Junior World Championship runner–up Yonger Bastida to claim gold at the Cerro Pelado International.

[38] Cox did not come back to action until a year later when he competed at a series of FloWrestling events, compiling six more wins in total during January and February 2021.

[41] Days later, more detail was given to the public, and it was explained that Cox had arrived to the weight-ins on time, but once he had stepped on the scale and successfully made the weight limit of 97 kg, it had been thirteen minutes past the 8:00 AM deadline, therefore, it was ruled as invalid by USA Wrestling.

[42] Cox explained that he was misinformed of the weight-ins schedule by his coach Kevin Jackson, who is part of USA Wrestling.

[48] He was once again able to show off his signature movements and went unscored throughout his championship run, downing NCAA champions Drew Foster and Myles Martin, as well as powerhouse Kollin Moore.

[50] In late 2021, it was announced that the brand RUDIS would organize an event headlined by a super match between Olympic, World and NCAA champion Kyle Snyder and Cox, which took place on March 16, 2022, in a best of three format.

Cathy has long been associated with Mizzou athletics herself: she regularly performs the national anthem at Tiger basketball games.

[5] Cox's uncle Phil Arnold was a two-time Missouri state champion for Hickman High School.

[4] The headgear Arnold used in winning his two titles is the same Cox and his older brothers wore during their high school careers.