Obstacle racing
An obstacle racer, dressed in costume, crawls through a mud pit topped with barbed wire.
Highest governing bodyWorld OCR, the Fédération Internationale de Sports d'Obstacles
TypeOutdoor or indoor
Country or regionWorldwide
A mud run participant climbs over a typical obstacle: the horizontal beam.
A mud run participant climbs over a typical obstacle: the horizontal beam.

Obstacle course racing (OCR) is a sport in which a competitor, traveling on foot, must overcome various physical challenges in the form of obstacles. Races vary in length from courses with obstacles close together to events of several kilometers[1] which incorporate elements of track, road and/or cross country/trail running. Courses may include climbing over walls or up ropes, monkey bars, carrying heavy objects, traversing bodies of water or mud, crawling under barbed wire, and jumping through fire.[2][3]

Since the beginning of modern OCR in 1987, the sport has grown in popularity such that more than 2500 events are held annually across the word[4] and several run organizing companies are commercially successful.[5]


1900 Olympics Obstacle Swim
1900 Olympics Obstacle Swim

Ancient history

From the stadion, the oldest event of the Ancient Olympic Games, to the contemporary era steeplechase, obstacles of some sort have been presented to athletes for thousands of years. The Ancient Olympic Pentathlon included five events contested over one day, thought to have started with the stadion (a short foot race) followed by the Javelin throw, Discus throw, Long jump and ending with wrestling. The event was first held at the 18th Ancient Olympiad around 708 BC,[6] and is quite similar to the modern day Spartan Race, which includes running, javelin (spear) throw, jumping and wrestling with various objects and weights.

Early history

The concept of using obstacles for competition has been in use since the 1800s, including the 200m Obstacle Swim at the 1900 Summer Olympic Games in Paris, with the first formal land based races in the Obstacle Run[7] of Military Pentathlon, first held at the Military Physical Training Centre, at Freiburg, in the French occupation zone in Germany, in August 1947. Only Belgian, Dutch, and French teams took part in the competition. Since 1950, annual world championships have been held. The sport has grown in popularity, and now over 138 countries participate in the World Military Games.[8] The sport's governing body, the International Military Sports Council (CISM), now also organise pentathlons aimed at naval and air force personnel.

Modern history

It is widely thought that Tough Guy is the earliest contemporary OCR, with the first race held in 1987. The race has been running continually since its inception and continues to attract contemporary and professional athletes.[9] The Survival Run also emerged in the late 1980s as a competition in the Netherlands. This originated as a way to run across the Dutch rural landscape, crossing streams, canals and other natural terrain. Events like Hang-On Run[10] can trace their origins back to Survival Running. The HiTec Adventure Racing Series (1996 - 2002)[11] was an early version of the contemporary race and included "special tests" (man made obstacles with walls, nets, etc.), mountain biking and kayaking. The Balance Bar races in the United States expanded on the success of the Hi Tech series, including a televised national series and championships.[12] The Muddy Buddy races in the United States (results here[13]) were a national obstacle race series produced by Competitor Group from 1999 to 2013 and was the first major series to introduce mud elements and remove additional equipment. Muddy Buddy was the event format that transitioned adventure racing to obstacle racing as we know today.

Military Obstacle Course
Military Obstacle Course

Contemporary races

There are many variations of obstacle race courses that accommodate a wide variety of athletes. Ninja races such as the Wolfpack Ninja Tour[14] are typically 50 m to 100 m in length with many obstacles and little running. OCR track races[15] are typically held on athletic tracks and vary between 400 m and 5,000 m. Cross country courses range from one mile and up, with most races between 5 km and 10 miles.

Longer endurance races vary up to 100 miles, including Spartan Beast, Ultra Beast and Agoge. Fixed time events include World's Toughest Mudder (24 hours), Spartan Ultra World Championships and the 36 hour Agoge.

Obstacle Course Races with inflatable obstacles are becoming increasingly popular, including Britain's GUNG-HO race.[16]

Development of the sport

Spartan Race founder Joe Desena set a goal to take the sport to the Olympics and tapped event and television producer Ian Adamson for the task in 2014. He subsequently founded the international sporting federation, now known as World Obstacle,[17] the Fédération Internationale de Sport d’Obstacles (FISO), based in Lausanne, Switzerland.[18] World Obstacle is a non-profit, member based sporting organization and the sole world governing body for Obstacle Course Racing. As of 2021, World Obstacle had national member federations in 108 countries in four continental regions (Africa, Americas, Asia-Pacific, and Europe), the largest number being in Europe.[19] World Obstacle applied for membership of GAISF in 2017, with a goal of having obstacle course racing and related disciplines recognized as an international sport by the International Olympic Committee.

It has been noted that World Obstacle has no member race organizations. As a not for profit sporting federation the only members of World Obstacle are national federations (national governing bodies.) The members the national federations are athletes and athlete based organizations. Brands and for profit corporations are not members of sporting federations, but can be recognized or aligned under certain circumstances.

In the summer of 2017 an application by UIPM (Modern Pentathlon) to add obstacle laser run as a mixed team medal event was rejected for the 2020 Olympics.

Full medal events for OCR were included for the first time in an International Multisport Games in the 2019 South East Asia Games. Medal events were approved for 100 m, 400 m and 5 km distances.[20] The SEA Games are under regulation of the Southeast Asian Games Federation (SEAGF) with supervision by the International Olympic Committee (IOC) and the Olympic Council of Asia (OCA).

OCR Asian Championship Podium
OCR Asian Championship Podium

The sport disciplines of Ninja (American Ninja Warrior), OCR and Adventure Racing became self governing sub-sports of World Obstacle in 2020,[21] in a model similar to Aquatics. The first non-commercial (Federation) Ninja World Championships was held in Moscow, Russia in 2019 Ninja World Championships.

In August 2020 World Obstacle and the International Parkour Federation (IPF) signed a Memorandum of Understanding[22] to unify Obstacle Sports worldwide under a governance model similar to Aquatics (FINA). The MOU expired at the end of 2020. IPF had signed an MOU with Gymnastics (FIG) in January 2018,[23] but were unable to come to an agreement and the term expired.

The OCR 100m international standard format (used in the SEA Games)[24] was first presented in Europe at OCR Polska's 2020 Polish Championships.[25] This event has over 80 million facebook views.[26]

Athlete Development

In recent years, obstacle course racing has been emerging onto the college scene in the United States. Universities, like Texas A&M University, have launched organizations and club teams[27] that feature obstacle course training.

World Obstacle provides at-cost athlete and coach development to all member federations World Obstacle Coach Development. Delivery of Level's 1 and 2 are delivered as eLearning on a Learning Management System meeting the international education framework.

OCR training education such as Spartan SGX are available at commercial rates.

Notable events

Muddy Buddy

Muddy Buddy[28] (1999 - 2010) was the first national OCR series in the United States emphasising man made obstacles and mud. Unlike later OCRs it included a bike leg, making it a "ride and run" OCR. The event series was produced by Competitor Group and sponsored by Columbia in later years.[29] Muddy Buddy ultimately went out of business under pressure from Tough Mudder and Warrior Dash which had simpler run-obstacle formats.

Rugged Maniac

Main article: Rugged Maniac

Rugged Maniac 2015. Four men offer a helping hand up the Warped Wall in Rugged Maniac.
Rugged Maniac 2015. Four men offer a helping hand up the Warped Wall in Rugged Maniac.

Rugged Maniac was founded in 2010 by former lawyers Brad Scudder and Rob Dickens. The very first race was held in October 2010, in Southwick, Massachusetts. It has since expanded to 24 cities over the United States and Canada.[30]

In 2014, they were featured on ABC's Shark Tank and secured a $1.75 million deal with Mark Cuban, the billionaire entrepreneur and owner of the Dallas Mavericks.[31] On January 16, 2016, Rugged Maniac (Under their company name Rugged Races LLC), appeared again on Shark Tank in an update video.[32] Since first appearing on the show, the Rugged Maniac event has expanded to Canada, increased in sales from $4.2 million to $10.5 million before and after Shark Tank, expanded to 28 cities, and created a second race called "The Costume Dash 5K", which debuted in Boston in October 2015.[33][34]

Rugged Maniac features 25 obstacles over a 5 kilometer (3.1 mile) course. It is designed to be more family-friendly and catered to people of all fitness levels, due to the shorter distance but larger number of obstacles. The run ends with an all-day festival of beer, food, mechanical bull riding, adult-sized bounce houses, and sponsor exhibition booths.[35]

Spartan Race

Main article: Spartan Race

Spartan Race[36] (2010) was an outgrowth of the annual Death Race (started in 2005),[37] with courses vary in distance and difficulty from "Sprint" courses (3+ mile with 20+ obstacles ), to "Super" (8+ mile with 20+ obstacles), and "Beast" course (13+ mile with 30-35+ obstacles). For endurance enthusiasts, Spartan also offers the "Ultra Beast" which is 2 times through the "Beast" course (later change to "Ultra" for 30 miles) and the "Hurricane Heat" which involves tasks that set up the obstacle course the night before. Average finishing times for the events range from 30 minutes to 6 hours, depending on the particular course and fitness level of the racer. Race venues are located around the world and have included ski slopes, state parks, paint ball parks, and more. Any competitor who completes a Sprint, Super, and Beast in one calendar year (Jan. 1 - Dec. 31) is said to have completed the Spartan Trifecta.[38] In the US, the Spartan Race World Championship was held in Killington, Vermont from 2012 until 2015 when it was moved to Squaw Valley near Lake Tahoe. The World Championship has been held in Squaw Valley in Olympic Valley, CA near Lake Tahoe every year since 2015. Prizes for World Championships in 2016 included: Overall Champions (Men' and Women's) 1st place $15,000, 2nd place $10,000, 3rd place $5,000, 4th place $4,000, 5th place $3,000; Elite Beast Championship (Men & Women's – 40+) 1st place $500, 2nd place $200, 3rd place $100; and Elite Ultra Beast Championship (Men & Women's) 1st place $1,000; 2nd place $500; 3rd place $250; 4th place $100; 5th place $100.[39]

Spartan Winter Race
Spartan Winter Race

The first Spartan Race World Championship was held in December 2011 in Glen Rose, Texas as an eight-mile Spartan Race course comprising 36 obstacles and included a US$20,000 prize purse. Beginning in 2012, the Spartan Race World Championships were held annually in Killington, Vermont, and at Squaw Valley, CA since 2015 with a total of $500,000 in cash and prizes.[40]

Spartan Races have occurred in more than 30 other countries around the world.  According to event organizers, obstacles vary from race to race. Obstacles during a Spartan Race can include climbing under barbed wire, wall climbing, mud crawling, a javelin throw, a rope climb, heavy object carries, slippery walls, a zig-zag log jump, steep mud climbs, tire flips and rope swings.[41]

Spartan Races hosted the Kids World Championship which was held on November 17, 2018. Boys and girls between the ages of 10 and 13 from around the world participated in the race.[42]

Tough Mudder

Main article: Tough Mudder

Tough Mudder Funky Monkey
Tough Mudder Funky Monkey

In 2010, Tough Mudder's first event was held in May 2010. The Tough Mudder is not technically a race and is instead focused on teamwork and completion of the event rather than finishing under a certain time.[43]

Tough Mudder courses are between 10 and 12 miles and contain various military style obstacles.[44]

The final event of the Tough Mudder season is the World's Toughest Mudder.[45] This is a 24-hour event in which competitors will run a shorter Tough Mudder course that has much more intense obstacles than a normal Tough Mudder and is designed to be more grueling as well. The goal for a participant in World's Toughest Mudder is to complete as many laps as possible within a 24 hours period. The athletes (solo male, solo female, team) who complete the most laps are declared the World's Toughest Mudder. The top male and female each receive $10,000 and the top team receives $12,000 (total).

Warrior Dash

Main article: Warrior Dash

The Warrior Dash was founded in 2009. Because Warrior Dash does not assign penalties for skipped obstacles, it is often considered an obstacle course event rather than a race. While Warrior Dash does not meet all the requirements to be considered a race, organizers do award their top finishers with non-cash prizes. All finishers receive a "warrior helmet" – a horned helmet.[46]

As a shorter event, winning times for a Warrior Dash may be as short as 15 minutes. While Warrior Dash features many of the same obstacles[47] found at other races such as mud crawls, water features, and cargo net climbs.

It was announced on July 31, 2019 that Red Frog Promotions would be shutting down their operations including Warrior Dash. Spartan Race purchased some of their assets, and instead of refunds for future events, Spartan would provide a replacement entry.

Terrain Racing

Terrain Racing[48] has 40 races in the United States each year on 5 km courses with 20+ obstacles.

Chakravyuh Challenge

Founded in 2016 and named after the near-invincible battle formation from Indian mythology (Chakravyuha), the Chakravyuh Challenge is the first obstacle course race to be hosted in the state of Kerala in India. The competition tests the participants' agility, bravery and problem solving capability by pitting them against obstacles involving slush, water, ropes, inclined slopes, team building exercises, fun mazes and more.

The race is open to both men and women and held in three variations - Individual Competitive Category, Team Challenge and Fun Run. With separate cash prizes awarded to the male and female winners of the first two categories. The obstacle race is part of a three-day adventure fest, held annually and the circuit itself is designed every year by former Indian Navy commandos.[49]

Adventurey OCR World Championships

The self named independent World Championship is an event owned and operated by Adventurey, a Brooklyn NY marketing and branding company.[50] The first race took place on October 25 & 26, 2014 in Cincinnati, Ohio. The men's event was won by UK's Jonathan Albon,[51] who successfully defended his crown in 2015[52] and 2016.[53] and every consecutive year through the current 2019 season. For the women, the inaugural event was won by Siri Englund of Sweden in 2014[54] and then Lindsay Webster of Canada in 2015[55] and 2016.[56] With participation of the sport growing, the organization added a 3 km course and a team event in 2016.


Each BattleFrog featured an 8 km course and at least twenty-five obstacles.[57]

In August 2016, BattleFrog canceled their remaining events for the season and no longer offers obstacle course races.[58]


BoneFrog features 50 Navy SEAL-style obstacles on courses that range from 3–9 miles. BoneFrog also offers an Endurance lap course and a three race Trident Series option. [59]


The GORUCK challenge offers varying levels of difficulty, while not being a race but a military service and teamwork event.

Savage Race

Savage race offers about 14 races in a year. They have two race types, SavageRace with 27 obstacles with a distance of 5-7 miles, and SavageBlitz with 15 to 20 obstacles over 3+ miles.

Notable European events

Icy watermoat at Getting Tough - The Race
Icy watermoat at Getting Tough - The Race

Rough Runner

Launching in the UK in 2015 as a reaction to the hard-core image created by the multitude of tough, military-style obstacle events, Rough Runner introduced an event with multiple distance options to cater to a wider array of fitness levels with a 5 km, 10 km and 15 km course to choose from. To reinforce the message of accessibility, Rough Runner's obstacles are inspired by fun-but-challenging TV game shows such as Gladiators, Total Wipeout and Ninja Warrior, with each event featuring The Travelator as the finish line obstacle.

Nuclear Races

Operating from their permanent site in Brentwood Essex, Nuclear races are fast becoming the most well received and attended event within the UK. They hold different events in April, September and November. Amongst their many obstacles is their signature "Death Slide" and the worlds longest permanent monkey bars. Nuclear Races will be the hosts of the OCRWC (Obstacle course racing world championships) 2018.

Tough Guy

First staged in 1987, Tough Guy claims to be the first official and toughest obstacle course race in the world. It is held on the last Sunday in January in Perton, Staffordshire, UK. The race is held twice a year in winter and summer. The winter event requires competitors to compete in near freezing temperatures and contend with ice and snow.[60][61] The 2013 event was won by Knut Höhler.[62]

Strong Viking

Strong Viking[63] is an event series based in Holland, with 32 races across Holland, Belgium, Denmark and Germany.


Toughest[64] is a race series based in Sweden, with 15 events across Scandinavia.

Bog Commander

Bog Commander combines fell running with obstacle course racing and mud running. Hailed as possibly the toughest off-road event in the UK. Set on a working hill farm in the spectacular Peak District, this course has been described as "extreme" and "brutal" by its participants. Terrain varies from 1200 ft to 1500 ft and includes natural bogs, river runs, massive hills and rough terrain. Man made obstacles including a 260 metre zip wire, complete the challenge.[65][citation needed]

Legion Run

Founded in Cyprus in 2013, Legion Run[66] is the only obstacle course based in south-eastern Europe. With a motto of ‘We are Legion, we are one of many, we are you’, this non-competitive event emphasizes teamwork and overcoming personal challenges. Legion Run has held successful events in Cyprus, Bulgaria, Greece, Hungary, Poland, Romania, Ukraine, Lithuania, Israel, Slovakia and has quickly established itself as a favorite in the region, particularly amongst members of the CrossFit and combat sport communities, as well as corporations, armed forces and other organized teams.

Legion Run involves a 5 km course with at least 15 obstacles, along with a parallel all-day festival for both participants and spectators. Every participant that crosses the finish line is awarded an exclusive ‘I Am Legion’ T-shirt and a well-deserved beer. In keeping with the team spirit of the event, there are no individual prizes or distinctions, however many participants choose to time themselves.[67]

The Suffering Obstacle Race

The Suffering Obstacle Race was established in 2012. This event offers obstacle races of distances varying from 5K, 10K, 10 miles, and 20 miles. The race ceased operation in 2017 leaving many participants out of pocket and with no refund[68][69]

Getting Tough - The Race

Since 2011, each year on the first Saturday in December, taking place in Rudolstadt, Germany. Labelled as "Europe`s hardest Obstacle Race" and voted "Best Obstacle Race in Germany" this Race is part of a full Weekend Event, including a "Sprint at Night" on Friday and a huge After Race Party on Saturday. 24 km, 1000 meter elevation gain, 180 Obstacles and much icy water results in most runners suffering of hypothermia at the finish line. Especially the last 3 km 'Killing Fields' are packed with Obstacles and topped of by the `Walk of Fame`, a 1 km long Obstacle park.[70]

Notable African events


THE IMPI Challenge Obstacle Trail Run is staged in South Africa.[71]

Warrior Race

Warrior Race[72] is South Africa's largest obstacle course race with up to 9000 participants per event. The Warrior Race offers race distances ranging from 5 to 21 kilometers.

Notable South American events

ROC Obstacle Course

ROC [73] is the biggest race in South America with 2000+ racers. The 8K course includes 35 obstacles. Since 2018 it's an official OCR World Championship Qualifier Race.

Carrera Sucia

Carrera Sucia [74] was the first OCR race done in South America back in 2012. With 5K and 20 obstacles is a fun run full with mud for runners all ages. With more than 20 races since its first event, Carrera Sucia has produced more than 30,000 muddy smiles.

See also


  1. ^ "Obstacle sports disciplines". World Obstacle. Retrieved January 26, 2022.
  2. ^ Schlachter, Margaret (June 5, 2017). "OCR 101: What Kind of Obstacles Will I find at an Obstacle Race or Mud Run?". Mud Run Guide. Retrieved January 26, 2022.
  3. ^ Heath, Neil; Aloia, Andrew (March 26, 2017). "Mud, sweat and cheers: The rise of obstacle course racing". BBC News. Retrieved January 26, 2022.
  4. ^ "Obstacle course racing". World Obstacle. Retrieved January 26, 2022.
  5. ^ Perez, A. J. (2015). "Obstacle races going mainstream, more popular than marathons". USA Today. Retrieved January 26, 2022.
  6. ^ Sweet, Waldo E. (29 October 1987). Sport and Recreation in Ancient Greece. ISBN 9780195364835.
  7. ^ "Military Obstacle Run Video". YouTube.
  8. ^ "CISM -Members Nations of International Military Sports Council". www.milsport.one. Retrieved 2019-01-02.
  9. ^ "toughguy | HISTORY". toughguy. Retrieved 2019-01-02.
  10. ^ "Hang-On Run". Hang-On Run. Retrieved 2019-01-02.
  11. ^ "Hi Tec Race Series retrospective". 9 February 2017.
  12. ^ "Outdoor Industry Balance Bar TV Series Press Release".
  13. ^ "Muddy Buddy Results 2004 - 2008".
  14. ^ "Wolfpack Ninja Tour race series".
  15. ^ "OCR Track Race Video". YouTube.
  16. ^ "Gung-ho Obstacle Video". YouTube.
  17. ^ "World Obstacle website".
  18. ^ "Outdoor Sportswire Press Release". 21 February 2018.
  19. ^ "World Obstacle Membership".
  20. ^ OCR, World. "Multisport Games | World OCR". World OCR. Retrieved 2019-01-02.
  21. ^ "World Obstacle website".
  22. ^ "IPF and World Obstacle sign memorandum of understanding".
  23. ^ "IPF and FIG sign memorandum of understanding".
  24. ^ "World Records Set in Obstacle Course Racing at the 2019 South East Asia Games". 13 December 2019.
  25. ^ "OCR Polska 3rd National Championships".
  26. ^ "OCR Polska 100m National Championships". Facebook.
  27. ^ "Texas A&M OCR Club".
  28. ^ McDowell, Dimity (2011-04-21). "Spice Up Your Training at a Muddy Buddy Race". ACTIVE.com. Retrieved 2018-12-26.
  29. ^ "Best Obstacle Races". Men's Journal. 2012-11-02. Retrieved 2018-12-26.
  30. ^ "Rugged Maniac 5k Southwick MA October 2, 2010 Results". Cool Running. October 2, 2010.
  31. ^ Ainsworth, Chip (April 28, 2014). "Extreme Business". The Recorder.
  32. ^ Huffman, Rex (January 15, 2016). "'MasterChef: Junior Edition,' 'Shark Tank' on tap tonight". TimesReporter.com.
  33. ^ Burnett, Mark (January 15, 2016). "Shark Tank". television. Season 7. Episode 14. ABC.
  34. ^ Weaver, Alex (October 26, 2015). "1,500 Costumed Crazies Will Run the Streets of Boston This Halloween". BostInno.com.
  35. ^ LeBlanc, Pam (August 26, 2015). "Giant water slides, tunnels, trampolines and more at Rugged Maniac obstacle race Sept. 5". Austin360.
  36. ^ "Spartan Race".
  37. ^ "Mountain Times Death Race article".
  38. ^ "Spartan Race types". Spartan Race. Retrieved 2016-11-18.
  39. ^ "Prize Money".
  40. ^ Schlachter, Margaret (November 21, 2016). "Spartan Race World Championship Returns to Tahoe in 2017". www.mudrunguide.com. Mud Run Guide. Retrieved January 8, 2017.
  41. ^ Advance, SHANNON KEITH The (Lynchburg) News &. "Rain only makes Spartan Race more fun". The Daily Progress. Retrieved 2018-11-07.
  42. ^ Nall, McGee (2018-12-01). "Obstacle-Crushing Tweens Compete for Podium in First-Ever Spartan Kids World Championship". Runner's World. Retrieved 2018-12-04.
  43. ^ "Tough Mudder 10M".
  44. ^ "What is Tough Mudder".
  45. ^ "World's Toughest Mudder".
  46. ^ "Warrior Dash".
  47. ^ "Warrior Dash Obstacles".
  48. ^ "Terrain Racing Website".
  49. ^ "An adventure challenge". The Hindu. India.
  50. ^ "Adventurey LLC on LinkedIn".
  51. ^ "2014 OCR World Championships - Men's Elite - Official Race Results". OnlineRaceResults.com. Retrieved 2017-05-05.
  52. ^ "2015 OCR World Championships - Men's Elite - Official Race Results". OnlineRaceResults.com. Retrieved 2017-05-05.
  53. ^ "2016 OCR World Championships - Men's Pro 15KM - Official Race Results". OnlineRaceResults.com. Retrieved 2017-05-05.
  54. ^ "2014 OCR World Championships - Women's Elite - Official Race Results". OnlineRaceResults.com. Retrieved 2017-05-05.
  55. ^ "2015 OCR World Championships - Women's Elite - Official Race Results". OnlineRaceResults.com. Retrieved 2017-05-05.
  56. ^ "2016 OCR World Championships - Women's Pro 15KM - Official Race Results". OnlineRaceResults.com. Retrieved 2017-05-05.
  57. ^ "BattleFrog | We are Battlefrog Obstacle Race Series". Archived from the original on 2015-11-26.
  58. ^ "Battlefrog Cancels Races". Retrieved October 20, 2016.
  59. ^ About Bonefrog | Obstacle Course Race
  60. ^ "Tough Guy 2014 - The Atlantic". www.theatlantic.com. Retrieved 2020-09-28.
  61. ^ "Always With A Smile: Tough Guy is a flaming hard event". hinckleytimes. 2014-02-04. Retrieved 2020-09-28.
  62. ^ "Un médico alemán de 29 años gana Tough Guy, la carrera más bestia del mundo | Teinteresa". www.teinteresa.es. Retrieved 2020-09-28.
  63. ^ "Strong Viking Website".
  64. ^ "Toughest Race Website".
  65. ^ Bog Commander Mud Run & Obstacle Race - Peak District
  66. ^ "Legion Run Website".
  67. ^ Legion Run
  68. ^ thesufferingrace.co.uk
  69. ^ Pain & Suffering Review - It's Not Like They Didn't Warn Us - Mudstacle
  70. ^ Home
  71. ^ "Challenge Obstacle Run website".
  72. ^ "Warrior Race Website".
  73. ^ "ROC Obstacle Course website".
  74. ^ "Carrera Sucia Website".

Further reading