Question: Matt Hume and Demetrious Johnson are both American participants of what sport

full_context: Document 1: KHK MMA: The Khalid Bin Hamad Al Khalifa Mixed Martial Arts (KHK MMA) is a martial arts organization based in Bahrain. It was founded under the patronage of His Highness Khalid bin Hamad Al Khalifa for its current CEO and professional MMA fighter Mohammed "The Hawk" Shahid in February 2015. Fighters competing under KHK MMA banner include: former UFC lightweight champion Frankie Edgar, UFC lightweight contender Khabib Nurmagomedov, UFC lightweight fighter Islam Makhachev, Bellator fighter James Gallagher, 2-time IMMAF champion Jose "Shorty" Torres, former UFC fighter and current Titan FC contender Alex Soto, and current Desert Force fighter Hamza Kooheji. KHK MMA activities include: coaching pro fighters, developing amateur MMA, promoting martial arts events, fitness gyms, and a sports gear brand.
Document 2: Bibiano Fernandes: Bibiano Fernandes da Silva Neto (born March 30, 1980) is a Brazilian professional mixed martial artist who has competed for K-1, DREAM, ONE Championship and King of the Cage. He was the first DREAM Featherweight Champion and DREAM Bantamweight Champion, and currently the ONE Bantamweight Champion. He is currently ranked as the #5 Bantamweight in the world by MMA Weekly and Fight Matrix as well as the #1 bantamweight outside of the UFC He is the main sparring partner of UFC Flyweight champion Demetrious Johnson.
Document 3: Anthony Pettis: Anthony Paul Pettis (born January 27, 1987) is an American mixed martial artist currently competing as a Lightweight in the Ultimate Fighting Championship (UFC), where he is the former UFC Lightweight Champion. Pettis was also the final WEC Lightweight Champion prior to the promotion being merged into the UFC. At one point, he was ranked as a top-ten pound for pound fighter. He is currently ranked #13 in the official UFC lightweight rankings.
Document 4: Matt Hume: Matt Hume (born July 14, 1966) is an American mixed martial artist. He is the founder and head trainer at AMC Pankration in Kirkland, WA, which is home to UFC flyweight champion Demetrious Johnson, ONE bantamweight champion Bibiano Fernandes and he has trained numerous world class fighters including Josh Barnett, Tim Boetsch Bob Sapp, Chris Leben, Hayato Sakurai, Akira Shoji, Matt Brown, Rich Franklin, Mario Miranda and Caros Fodor.
Document 5: Pat Miletich: Patrick Jay "Pat" Miletich ( ; born March 9, 1966) is a retired American mixed martial artist and a current sports commentator. He is known for his fights in the Ultimate Fighting Championship, where he became the first UFC Welterweight Champion and UFC 16 Welterweight Tournament Winner. Miletich is also known as a highly successful trainer and coach, having founded Miletich Fighting Systems. This camp is considered one of the most successful in MMA history and has produced several world champions. On July 6, 2014, he was inducted into the UFC Hall of Fame.
Document 6: José Aldo: José Aldo da Silva Oliveira Junior (] ; born September 9, 1986) is a Brazilian mixed martial artist in the Ultimate Fighting Championship. He was the fourth and final WEC Featherweight Champion and thus, became the first UFC Featherweight Champion during the UFC/WEC merger. He is a former two-time UFC Featherweight Champion. He was named Sherdog's 2009 Fighter of the Year. He is currently #12 in official UFC pound-for-pound rankings, having been ranked as high as #1 in 2015, and ranked the #2 featherweight in the world and #7 pound-for-pound by Sherdog. In the decade from November 2005 through December 2015, Aldo was undefeated in 18 fights. In Sherdog's April 2017 Pound-For-Pound ranking, Aldo was called "the greatest featherweight in mixed martial arts history."
Document 7: Team Hammer House: Team Hammer House is a mixed martial arts team operating out of Columbus, Ohio, made up of mostly former NCAA wrestlers. While Hammer House focuses on amateur wrestling they do have cross training deals with notable fighters and camps such as Matt Serra, Pat Miletich and Xtreme Couture Mixed Martial Arts. Founded by former UFC champion Mark Coleman, Team Hammer House has attracted such mixed martial arts fighters as Kevin Randleman and Phil Baroni.
Document 8: Demetrious Johnson (fighter): Demetrious Khrisna Johnson (born August 13, 1986) is an American mixed martial artist. He is the first ever and the current Flyweight Champion of the Ultimate Fighting Championship (UFC). He currently holds the longest active championship reign at ten title defenses. He is also the #1 ranked pound for pound MMA fighter in the world. Known for his quick striking and elusive movement, Johnson has also landed the most takedowns in UFC Flyweight history and holds the record for the latest finish in UFC history with a submission win at 4:59 of the fifth round against Kyoji Horiguchi. He is also the only UFC fighter to record over 10 takedowns in three different fights.
Document 9: B.J. Penn: Jay Dee "B.J." Penn (born December 13, 1978) is an American professional mixed martial artist and Brazilian Jiu-Jitsu practitioner. Penn debuted and competed in the Ultimate Fighting Championship (UFC), and later in K-1. Prior to fighting for the UFC, he became the first American Gold medalist of the World Jiu-Jitsu Championship. In mixed martial arts, Penn has competed in the Featherweight, Lightweight, Welterweight, and Middleweight divisions. As a former UFC Lightweight Champion and UFC Welterweight Champion, he is one of only three fighters in UFC history to win titles in multiple weight classes. Penn was also a Co-champion in the UFC 41 Lightweight Tournament, due to an eventual draw opposite Caol Uno in the tournament finale. Through his tenures as champion, Penn unofficially unified the UFC Lightweight Championship (against Sean Sherk) and broke the all-time lightweight title defense record. Penn was inducted into the UFC Hall of Fame, as the inaugural inductee in the Modern-Era Wing by career-long rival Matt Hughes, during "International Fight Week" in July 2015.
Document 10: Donald Cerrone: Donald Anthony Cerrone ( ; born March 29, 1983) is an American professional mixed martial artist and former professional kickboxer currently competing in the UFC's Lightweight and Welterweight divisions. He is ranked #6 in the official UFC Welterweight rankings tied with fellow Welterweight contender Neil Magny. A professional competitor since 2006, Cerrone has also formerly competed for the WEC. Cerrone currently holds the record for most post-fight bonuses (Fight/Performance of the Night, Knockout/Submissions of the Night) in UFC/WEC history with 18. He is also known as the "busiest" fighter in the UFC, due to consistently having at least four fights per year since 2013.
Document 11: Khabib Nurmagomedov: Khabib Abdulmanapovich Nurmagomedov (Russian: Хабиб Абдулманапович Нурмагомедов ; Avar: ХIабиб ГӀабдулманапил НурмухӀамадов ; born September 20, 1988) is an undefeated Russian mixed martial artist of Avar heritage. He is a two time Combat Sambo World Champion, a wrestler and a judo black belt who currently fights in the Lightweight division of the Ultimate Fighting Championship. He currently holds one of the longest undefeated streaks in MMA with 24 wins. As of 17 November 2016, he is ranked the #1 contender in the UFC Lightweight division and #12 in official UFC pound-for-pound rankings and numerous other publications.
Document 12: Michael Johnson (fighter): Michael Julian Johnson (born June 4, 1986) is an American mixed martial artist who competes in the lightweight division of the Ultimate Fighting Championship. A professional MMA competitor since 2008, Johnson mostly competed in his regional circuit, before signing onto the Ultimate Fighting Championship to appear on "". As of July 2017, he is #9 in the official UFC lightweight rankings.
Document 13: Matt Serra: Matthew John Serra (born June 2, 1974) is an American former professional mixed martial artist, Brazilian Jiu-Jitsu practitioner who competed for the Ultimate Fighting Championship and stand up comic. He currently serves as a UFC on FOX analyst. Serra defeated Pete Spratt, Shonie Carter and Chris Lytle en route to becoming The Ultimate Fighter 4 Welterweight Tournament Winner. He captured the UFC Welterweight Championship immediately after, becoming the first of only four to win both accolades (along with Forrest Griffin, Rashad Evans, Michael Bisping). Serra also served as the head coach for "The Ultimate Fighter 6" reality show opposite Matt Hughes. In Brazilian Jiu-Jitsu, Serra holds a Silver Medal in the ADCC Submission Wrestling World Championship.
Document 14: Jim Miller (fighter): James Andrew Miller (born August 30, 1983) is an American mixed martial artist. He is currently a competitor in the UFC's lightweight division. He currently holds the record of most wins in the UFC lightweight division and is the younger brother of former UFC fighter Dan Miller.
Document 15: Matt Hughes (fighter): Matthew Allen Hughes (born October 13, 1973) is a retired American mixed martial artist with a background in wrestling. He is a two-time UFC Welterweight Champion, UFC Hall of Fame inductee, and NJCAA Hall of Fame inductee. During his tenures in the Ultimate Fighting Championship, Hughes put together two separate six-fight winning streaks, defeated all the available opposition in the welterweight division, and defended the belt a then-record seven times. Hughes was inducted into the UFC Hall of Fame in May 2010 during the UFC Fan Expo in conjunction with UFC 114.
ground_truth: mixed martial artist