Please note this is an old version of this entry, which may differ significantly from the current revision.
The proliferation and emergence of new sport modalities has been remarkable. At an international level there is a constant renewal of the sports catalogue, and in Spain this situation has not been any different. A clear example is trail running (TR), skyrunning (SR), and mountain running (MR), which have settled in the sports scenario, especially in Spain, where they are highly accepted among runners. Mountain running (MR) is a sport practice that in recent years has been studied and analyzed, taking into account the social, media, environmental, and economic impacts that it has and is generating in society and the Spanish region.
1. Modality Definition
Before mentioning how the different organizations have defined the modality they manage, it is important to emphasize what running in the natural environment means. A distinction must be made between the regulated and non-regulated practice of what could be understood by running in mountain areas, which according to the terminology of the Regulations on Natural Areas II of the Spanish Federation of Mountain Sports and Climbing 
, is as follows: “The modality consists of running through mountain areas”.
This modality involves moving through different natural environments with highly variable morphological and meteorological characteristics, which often involves considerable physical effort 
Even if it is with only one organization, it could be aware of the implications of running in mountain areas, but what are TR, SR, and MR? In order to approach it, how the different organizations define them both at a national and international level will be explained. The conclusion drawn from this is that they always refer to the same sport modality.
The International Association of Athletic Federations (IAAF) defined trail running in article 252 of the competition regulations as follows: Trail runs take place on a wide variety of terrain (including dirt roads, forest roads, and single-track trails) in a natural, open-field environment (such as mountains, deserts, forests, or plains) and mostly off-road. Paved or concrete-surface pathways are acceptable, but they must be the minimum possible to achieve the desired run and not exceed 20% of the total run distance. There is no limit for distance or elevation gain uphill or downhill 
. It is managed by its associate members, such as the International Association of Ultrarunners (IAU) and the International Trail Running Association (ITRA), who organize (in the case of the IAU and those sponsored by the IAAF), in addition to their own competitions, the TR World Championship on a jointly basis.
Article 251 of the competition regulations includes mountain running (MR), which the IAAF 
has defined it as follows: “Mountain running is carried out on terrain that is mostly off-road, unless there is a significant elevation change, in which case a paved surface is acceptable. Distance can vary from 1 km to marathon length. The slope should be at least 5% and should not exceed 20%”. It is managed at the international level by the World Mountain Running Association (WMRA), an associate member of the IAAF, which also defined mountain running (MR).
In addition, article 250 of the competition regulations also recognizes cross country, which has been defined as “races through open or wooded areas on grassy terrain, which may include partly gravel, roads, and hills as long as these are limited to a minimum and also include natural obstacles” 
The ITRA 
, an associate member of the IAAF, presented TR as “a foot race, open to all, in a natural environment (mountain, forest, plains), with the minimum possible number of asphalt or paved routes, which should not exceed 20% of the total course”.
On the other hand, the American Trail Running Association 
made a broader description of the concept of trail runs, which was defined as “races that not only run on off-road trails but can also include paved roads in rural and urban areas,” while adding that in order to be considered a trail run, they must run on tracks or roads inaccessible to motor vehicles.
World Tour 
, a private race circuit, made it clear that trail runs should illustrate the diversity of the event, including steep roads, trails, hills, beaches, or desert, by applying for the definition of the Ultra-Trail®
circuit, which includes five unique criteria that the event must have, such as a distance of at least 100 km, an emblematic location, at least 500 participants, an international event with at least 20 different nations represented, and at least two editions of the event having been held.
It should be noted that Ultra-Trail®
is a registered trademark of the company organizing the Ultra-Trail du Mont Blanc®
(UTMB), more specifically by the SARL Autour Du Mont Blanc, directed by Catherine Politte and Michel Politte, and that has co-organized, in addition to the UTMB, the ByUTMB franchised racing circuit around the world since 2018 and the UTWT, to which the UTMB belongs (they are one of the eight most important event organizers in the world, being the founding members of the UTWT in 2013). Moreover, they are both founding members of ITRA, as stated in the statutes of 2 February 2019, approved in Milan 
On the other hand, it could be mentioned that the International Skyrunning Federation (ISF), which represents the governing authority on SkyRunning®
and mountain running above 2000 m carried out on technical trails and whose practice is mainly included in the Sky, Ultra, and Vertical categories 
. According to the statutes of 23 July 2011 and the regulations of the competition, the definition for SR is as follows: “Running in the mountains above 2000 m of altitude, where the difficulty to climb does not exceed degree II and the slope is greater than 30%. Where the altitude does not reach 2000 m, the courses must have an average minimum of 6% of slope over the total distance and reach the highest points of the area”.
In the case of SkyRunning® it should also be remembered that it is a patent registered by Marino Giacometti (inventor of SR and founder of the ISF) and that it is exploited through SkyMan S.A.
In Spain, several organizations that have defined the modality practically like their international counterparts could be found, with the differentiation of concepts as far as the name is concerned. Thus, the Royal Spanish Athletics Federation 
, under the protection of the IAAF regulations, is in charge of managing trail running, MR, and cross country in Spain, defining TR as:
“Activity that consists of running in a natural environment in the open field (mountains, deserts, forests, beaches, or plains) where no more than 20% of the surface can be asphalted or paved. The path can be diverse (roads, trails, tracks…) and the route must be properly marked. Trail running allows a great variety of distances, slopes, terrains, and landscapes”.
Finally, at the national level, the other major protagonist of the mountain races in Spain is the Spanish Federation of Mountain Sports and Climbing 
, affiliated with the ISF and which has defined them as follows: “Mountain races consist of running along paths or virgin areas that are characterized by their steep slopes and their technical difficulty. They can be held in the high, medium, and low mountains, and always run along unpaved tracks and courses, paths, ravines and so on also the race route does not exceed 50% of the track accessible to vehicles. The minimum distance for a circuit to be considered an official competition, except in the case of the Vertical Kilometer, is 21 km, with a minimum accumulated difference in height of 1000 m. Depending on the terrain on which the competition takes place, the races may include climbing up and down with ropes, although the area climbed may not exceed grade II of difficulty or 40° of slope”.
This definition of MR is practically identical to that of SR, with the difference in the conceptualization of what both organizations understand by their respective ways of naming the modality. Although at the international level the ISF has wanted to make a distinction between its modality as one of its own, SR, against another that is considered different at the level of the Spanish territory—TR—this has remained an administrative dispute over the term “TR,” to which both the RFEA and the FEDME refer as their own, both understanding that TR is either “Carrera de montaña” (RFEA) or “Carrera por montaña” (FEDME), both called in English “mountain running”.
2. Organizational Structure of the Modality
Sports regulated by sports federations and entities establish the management and administration of the sport on the basis of legal regulations, their respective rules, and their statutes. In the case of TR and SR, since they are sports that have evolved from an amateur perspective to a highly competitive one while conserving an added popular value with a particular meaning as far as terminology is concerned and taking into account that there is a good number of organizations in charge of their management (both at the international and national levels), it is easy to see that there is not one single classification system for them. Seguí et al. 
pointed out that in relation to the organizational structures of mountain and trail running, three basic aspects are considered: (a) the organizations carrying out the activity of mountain and trail running, (b) how they define the sport modality, and (c) how they conduct their respective championships.
From these three aspects listed by these authors that are already known the organizations and their respective definitions. As far as the organization of their championships is concerned, the subdisciplines of the modality must also be added, the different types of races, the categories, and the scoring and classification systems. Therefore, on a worldwide level, the following can be found:
The ITRA, as an international promoter of TR, has organized together with the IAU the World Championship of Trail Running (Individual and Team categories) since 2016. With the amendment by the IAAF of article 252 of the competition regulations, the ITRA decided in March 2018 to implement a new classification system for its races from XXS to XXL, based on the km/effort that the runner must exert, validating a new system of ITRA points (understood as a performance index) ranging from 0 to 6 depending on the km/effort. They have also collaborated in the organization and regulation of the Ultra-Trail® race circuit of the UTWT.
The IAAF, in addition to the trail races described in article 252 of its competition regulations and that it shares with the ITRA, has among its disciplines cross country, which was ruled in article 250 of its regulations; mountain running (MR), which was delegated to its associate member WMRA and whose regulation is located in articles 251 and 252; and ultra running, which was also delegated to the IAU for its management and organization of the respective championships sponsored by it and which was regulated in the same way as trail races and MR in article 252. Consequently, only the World Cross Country Championships are organized directly by the IAU, whereas the other disciplines are organized by its associate members.
The WMRA is the promoter of mountain racing worldwide. It organizes basically five events: World Mountain Racing Championship (Individual and Team categories), World Long Distance Mountain Racing Championship (Individual and National Team categories), World Masters Mountain Racing Championship, World Mountain Racing Cup (Individual category), and International U-18 Mountain Racing Cup (Individual and Team categories). It has a non-stop ranking in which the results obtained in the last 12 months are scored.
The IAU is responsible for promoting ultra-distance races (not only trail races but also asphalt, indoor, and track races). It has worked together with the ITRA since 2016 to organize the World Trail Running Championship. In addition, it organizes the 24 h, 100 km, and 50 km World Championships. Among its disciplines, as stated in its articles of incorporation of June 2016 (revision), are 50 km, 6 h, 100 km, 100 miles, 24 h, 48 h, 6 days, and 1000 miles for road and trail. It consists of a unique annual ranking for the disciplines of 50 km, 100 km, 100 miles, 6 h, and 6 days, in which one scores by completing races whose titles are Gold, Silver, and Bronze (with Gold granting more points and Bronze fewer).
The UTMB® has organized a unique annual event made up of seven races according to its competition regulations, which are the UTMB©, the Courmayeur-Champex-Chamoix (CCC®), the Sur les Traces des Ducs de Savoie (TDS®), the Orsières-Champex-Chamonix (OCC), the Martirgny-Combe à Chamonix (MCC), the Petite Trotte à Léon (PTL®), and finally, the Youth Chamonix Cormayeur (YCC). For participation in the first four races, it is necessary to accumulate a certain number of UTMB points, which can be obtained in third-party races authorized by the UTMB® called “qualifying races”, in which one can obtain from one to six UTMB points.
The UTWT is another major protagonist in Ultra-Trail® races due to being the main promoter of this distance in collaboration with the ITRA. In its competition regulations it presents an annual circuit of races in different categories and similar standards established jointly with the ITRA. Among the racing categories are Series Bonus, Series, Pro, Challenger, and Discovery races (the latter proposed as demonstration races with no possibility of scoring for the circuit). The UTWT currently has two classifications: the UTWT Annual Ranking, which takes into account the two best results obtained in races on the circuit as long as at least two of them are completed, and the UTWT World Ranking, which takes into consideration the five best results obtained in the last three years. In any case to qualify for any of the two rankings a series of UTWT points must be obtained, which depends on the category of the race and the position that each runner obtains.
The ISF shows a relatively more complex structure as far as the organization of its modality is concerned. The following disciplines were included in the competition regulations for the year 2019 
: Sky, Ultra, Vertical, Skyspeed, Skyscraper Racing/Vertical Running, Skybike, Skyraid, and Skyrunning Technical Level. Furthermore, the following terms are used to describe the types of races they offer: SkyRace®
, SkyMarathon, Ultra SkyMarathon, and Vertical Kilometer®
. Meanwhile, it has approved the following competitions: National Skyrunning Championships (developed by each nation based on the ISF regulations that have, firstly, an individual scoring system and secondly, a qualifying system based on the four best athletes in order to make up the national team, at least one per gender), Continental Skyrunning Championship (individual and team competition that has at least the categories of Sky, Vertical, and Ultra), Biannual World Skyrunning Championship (at least the Sky, Vertical, and Ultra disciplines are competed for and the title of each one is awarded not only combined, but also for national teams), World Youth Skyrunning Championships (held in the disciplines of Sky and Vertical, as well as three different categories—A, B, and U-23, which are awarded in the two disciplines), and Skygames (this type of competition is held every four years, coinciding with the Olympic Games in the disciplines of Sky, Vertical, and Ultra, but may also include others, such as Skyspeed, Skybike, or Skyraid, establishing an individual title for each of the disciplines as well as a combined title and another one for teams). In addition to the official championships, the ISF has also arranged a series of circuits with third parties that maintains the Skyrunner®
and Vertical Kilometer®
trademarks, where individual runners and teams can participate. Their importance depends on the media impact of these circuits. These circuits are the Vertical Kilometer World Circuit (races developed in the most emblematic skyscrapers in the world with only one general ranking of individual character), the Vertical Kilometer World Circuit (vertical kilometer racing circuit with only one general ranking of individual character), the Skyrunner National Series (with two absolute categories, male and female, in the Sky and Vertical disciplines and with a qualification system awarding points to the top 30; within these races, only those within the SkyMarathon modality score for the Skyrunner World Series and only the top 10 in each category), and the Skyrunner World Series (races with a single category called SkyRace, in which it is only possible to participate individually and whose scoring system is based on the name of each race, which may be SkyRace, SuperSky Races, or The SkyMasters. Each denomination offers a certain number of points according to the athlete’s position, taking into account only the first 20 of each category) 
Finally is the Golden Trail Series (GTS), with its two circuits—the Golden Trail World Series (GTWS) and the Golden Trail National Series (GTNS)—with unique absolute categories for each type and a classification system awarding points to the top 30 in each race.
Meanwhile, at the national level, the institutions with their own organizational structures and with real capacity to manage the TR/SR modality are:
The RFEA 
, acting in accordance with the IAAF, approved in its competition regulations the following disciplines at the Spanish level: cross country, and mountain and trail races, and on the basis of these disciplines, the following competitions have been organized: the Spanish Championship of Mountain Races—Trail Running, the Spanish Individual Championship of Trail Running, the Spanish Master Mountain Championship, the Spanish Master Trail Running Championship, the Spanish Championship by Trail Running Federations, the Spanish Championship of Trail Running Clubs, and the Spanish Championship of Mountain Running Clubs. In addition to those mentioned, the World Cross Country Championships are also organized in the Individual, Masters, Clubs, and Federations categories.
Additionally, FEDME described the following mountain-race disciplines in its 2019 competition regulations: Line Races, Vertical Races, Ultra Races, Mountain Snow Races, and other state-wide competitions and popular races. The different competitions authorized by FEDME are specified as follows: the Spanish Cup of Line Mountain Races (it consists of between three to six races of one day each and they are disputed in the individual modality), the Spanish Championship of Line Mountain Races (it consists of a single race in the individual modalities by clubs and by autonomous federations), the Spanish Cup of Vertical Mountain Races (it consists of between three to six races in the individual modality), the Spanish Championship of Vertical Mountain Races on the Mountain (it consists of a single race in the individual modalities by clubs and autonomous federations), the Spanish Ultras Championship (it consists of a single event in the individual modalities by clubs and autonomous federations of a maximum of two days), the Spanish Ultras Cup (it consists of between three and six events in the individual modalities of a maximum of two days each), and the Spanish Championship of Snow Mountain Races (it consists of a single event in the individual modalities by clubs and autonomous federations). In addition to the disciplines and competitions, FEDME has its own ranking, which takes into account the different disciplines (line, vertical, or ultra) according to the competition (cup, championship, or certified course), rating the latter differently and always taking into account those classified between positions 1 and 15, dividing in any case the ranking by male and female.
This entry is adapted from the peer-reviewed paper 10.3390/su141912401