In December 2014, Ruth trained with
mixed martial arts (MMA) fighter
Jon Jones. While living in
State College, Pennsylvania, Ruth trained at
Central PA Mixed Martial Arts with head instructor Ryan Gruhn.
Bellator MMA He signed with
Bellator MMA in May 2015. Due to his focus on competing in the
2016 Summer Olympics, Ruth declared that it would "be a little while" before his MMA debut. Ruth made his professional MMA debut in November 2016 on the undercard of
Bellator 163 against Dustin Collins-Miles, fighting in the middleweight division. He won the fight via TKO in the first round.' In his second professional MMA bout, Ruth faced Emanuele Palombi at
Bellator 168 on December 10, 2016. He again won via TKO in the first round. Ruth was expected to face Aaron Goodwine at
Bellator 178 on April 21, 2017 but the bout did not materialize. Ruth instead fought and defeated David Mundell. Ruth faced
UFC veteran
Chris Dempsey on November 3, 2017 at
Bellator 186. He won the fight via knockout in the second round. Ruth was originally scheduled to make his welterweight debut and face Lazslo Furko of
Hungary, but Furko pulled out due to injury. Ruth then faced Ion Pascu of
Romania, who took the fight on two weeks notice at Bellator 196 held in
Budapest,
Hungary. This fight was agreed at a catchweight of 175 lbs. He won the fight by unanimous decision after taking Pascu down numerous times and landing heavy ground and pound. Ruth made his welterweight debut against
Andy Murad at
Bellator 201 in
Temecula,
California. He won the fight by TKO in round two. Ruth next entered the
Bellator Welterweight Grand Prix. He faced
Neiman Gracie in the quarterfinals at
Bellator 213 on December 15, 2018. He lost the fight via rear-naked choke submission in the fourth round. After the loss, Ruth decided to leave Alliance MMA and join
American Kickboxing Academy. Ruth faced
Kiichi Kunimoto at
Bellator 224 on July 12, 2019 and won the fight via TKO in the second round. On August 15, 2019, it was announced that Ruth had signed an exclusive multi-fight, multi-year contract extension with Bellator. As the first fight of his new contract, Ruth faced
Jason Jackson at
Bellator 231 on October 25, 2019. He won the back-and-forth fight by split decision. 4 out of 6 media scores gave it to Jackson. Ruth faced
Yaroslav Amosov in the main event of
Bellator 239, on February 21, 2020. He lost the fight via unanimous decision. Ruth faced Taylor Johnson at
Bellator 245 on September 11, 2020. He lost the bout due to an inverted heel hook submission early in the first round. In July 2021, Ruth retired from MMA and took a job as assistant coach with the
University of Illinois wrestling program, joining head coach Mike Poeta in his first year at the helm of the program. == Championships and accomplishments ==