A look at some of those who competed in the Olympics for Team USA who have since turned to mixed martial arts.
Ben Askren, Olympics
The 2007 Missouri graduate made the 2008 U.S. Olympic wrestling team for freestyle and won his first bout. He then lost in the quarterfinals to Cuba's Ivan Fundora.
Ben Askren, MMA
Askren won the Bellator welterweight title in October 2010 and remained champion for three years before being released by the promotion. Askren (15-0, 1 no contest) is now the ONE welterweight champion.
Henry Cejudo, Olympics
Cejudo won gold at the Beijing Olympics in 2008 in freestyle wrestling. He beat Tomohiro Matsunaga of Japan in the final round of the 55-kg division.
Henry Cejudo, MMA
Cejudo won his first 10 pro fights and earned a title shot against UFC flyweight champion Demetrious Johnson which he lost in the first round.
Mark Coleman, Olympics
Coleman competed for Team USA as a freestyle wrestler at the 1992 Olympics in Barcelona, finishing in seventh place.
Mark Coleman, MMA
Coleman entered the UFC in 1996, became "the godfather of ground and pound," won the heavyweight title, fought in Pride and is a UFC Hall of Famer.
Daniel Cormier, Olympics
Cormier was a freestyle heavyweight wrestler for Team USA in the 2004 Olympics (Athens) where he finished fourth. For the 2008 Games in Beijing, Cormier was named team captain but he did not compete after suffering from a kidney ailment.
Daniel Cormier, MMA
Cormier has become one of the toughest fighters in the sport. He is the reigning UFC light heavyweight champion with only one career loss in 19 fights.
Ferguson competed in judo for Team USA in the 2004 Olympics in Athens (pictured in white). He reached the quarterfinals at men's half-heavyweight where he lost to eventual silver medalist Jang Seong-Ho of South Korea, then lost in the repechage round. In MMA, Ferguson, a four-time national judo champion, fought three times inside the cage, winning all three -- including knocking out an opponent in seven seconds.
Gardner won gold in Greco Roman wrestling at the 2000 Olympics in Sydney, Australia, and bronze in the 2004 Olympics in Athens, Greece. Gardner had one MMA fight and he won it. At PRIDE Shockwave 2004 on Dec. 31, 2004, Gardner won a unanimous decision over Hidehiko Yoshida, who was a former Olympic gold medalist in judo.
Rick Hawn, Olympics
Hawn was a three-time national champion in judo and made the 2004 Olympic team. He went 2-2 in his Olympic bouts and finished ninth.
Rick Hawn, MMA
Hawn began his MMA career in 2009 and has wins over notable fighters Lyman Good and Shonie Carter. He reached the welterweight tournament final in Bellator Season 5 where he lost to Long Island native Jay Hieron. Hawn is 21-4 and has fought for Bellator and Titan FC.
Dan Henderson, Olympics
Henderson was a Greco-Roman wrestler for Team USA in the 1992 Olympics (Barcelona) and the 1996 Games (Atlanta). He finished 10th in 1992 and 12th in 1996 while wrestling at middleweight (181 pounds).
Dan Henderson, MMA
Henderson was the only Pride fighter to hold the middleweight and light heavyweight titles at the same time. He also won the UFC 17 middleweight tournament in 1998 and the Strikeforce light heavyweight championship in 2011. He also won what many say is one of the best fights in MMA history, a five-round, back-and-forth slugfest with Mauricio "Shogun" Rua at UFC 139 in 2011. Five years later, at age 45, Henderson continues to fight in the UFC.
In the 1992 Summer Olympics in Barcelona, Jackson won the freestyle wrestling gold medal. He beat Elmadi Jabrailov of the Unified team in the final round. Jackson won the UFC 17 middleweight tournament in 1997 by submitting Tony Fryklund in his second fight of the night. Jackson went 4-2 during his MMA career from 1997-98. He fought in the early days of the sport when weight classes were an afterthought. He now coaches wrestling at Iowa State
Matt Lindland, Olympics
Lindland represented the United States in Greco-Roman Wrestling at the 2000 Summer Olympics in the 69-76 kg weight category, winning the silver medal.
Matt Lindland, MMA
Lindland (22-9) has fought in the UFC, Strikeforce, Affliction and IFL, to name a few. He began training MMA more than a decade ago with Dan Henderson and Randy Couture, a UFC Hall-of-Famer and three-time Olympic team alternate in Greco-Roman wrestling (1988, 1992 and 1996). Lindland last fought in 2012. In 2014, he was named USA Wrestling's national Greco-Roman team coach.
Sara McMann, Olympics
McMann, left, was the first American woman in history to win a silver medal in Olympic wrestling. She lost to Japan's Kaori Icho, from Japan in the women's freestyle 63kg final match at the 2004 Olympic Games in Athens.
Sara McMann, MMA
McMann won her first seven pro bouts. She has competed in Strikeforce, Invicta and the UFC, earning a title shot against Ronda Rousey. The veteran fighter in 9-3.
Miller won Olympic bronze in women's freestyle 63-kg wrestling at the 2008 Olympics in Beijing. She fought once in MMA, with a third-round TKO at Invicta 1 in 2012.
Ronda Rousey, Olympics
Rousey finished ninth in the 2004 Olympic Games in Athens. She was 17. At the 2008 Olympic Games in Beijing, Rousey won the bronze medal at middleweight, becoming the first American to reach the medal podium in women's judo since it became a full Olympic sport in 1992.
Ronda Rousey, MMA
Rousey turned to mixed martial arts in 2010 and turned pro in 2011. She won her first 12 fights, went beyond the first round once, won both the Strikeforce and UFC bantamweight championships and became one of the biggest stars in sports.
Schultz won a gold medal in freestyle wrestling in the 1984 Summer Olympics in Los Angeles. In MMA, Schultz defeated Gary Goodridge via TKO because of a cut at the 12-minute mark of a fight at UFC 9 on May 17, 1996, in Detroit.
Herschel Walker, Olympics
At age 29, during the NFL offseason, Walker helped the American bobsled team finished seventh at the 1992 Winter Olympics in Albertville, France.
Herschel Walker, MMA
At age 46, the former Heisman Trophy winner, made his MMA debut for Strikeforce, winning by third-round knockout. One year later, he knocked out his opponent in the first round.