MUT (Mountain, Ultra, Trail) running and racing is a subset of LDR (Long Distance Running). Because of the nature of MUT, the pace is generally a bit slower than shorter running events contested on the asphalt or the track. MUT running and racing require tremendous amounts of stamina.
MUT running and racing often occurs off the track and generally off paved roads. Well, at least for the Mountain and Trail events. Ultra running and racing may or may not use roads or even a track.
The Trail part most is easy to understand: it is run on trails. But, things in life are not always simple. Some people include Cross-Country in Trails, while others insist Cross-Country and Trail running are two distinct things. Indeed, the Cross-Country discipline has specific rules, including specific requirements for starting area, minimum with of course, and the finish chute. Trail running on the other hand pretty much says, “Here is a trail, have at it.” That trail at times may be wide enough to accommodate many runners, while at other spots may a single track wide enough for a single runner.
The Mountain part is also easy to understand. There is a perfectly good mountain sitting there minding its own business. Hey, let’s go run up it, run down it, or let’s be really adventurous and run it both ways!
Finally, we get to the Ultra part. Ultra running is generally anything exceeding marathon distance (42km, or 26.2 miles). Ultra events may be across any surface. For example, there are Ultra road races, Ultra races held on a track (some LDR events such as 6-hour, 12-hour, and 24-hour) are an LDR Ultra event. Remember, Ultra is not really a type of run, rather is a descriptor pertaining to distance. A 10k is an LDR event, but it is not an Ultra. After all, the term Ultra describes an event of distance exceeding 42km.
Ah, but some people seem to think the U in MUT is for Urban. Well, It does not. But, while we are describing stuff, we might as well describe Urban running and racing.
Urban running is the idea of using the city and urban areas (the generally densely populated region surrounding a city) as a playground. Urban runs and races often involve roads, sidewalks, parks, steps and stairs, and various obstacles. Following is an example of an Urban event, the Fresno Urban Run, in Fresno, CA:
Because of the nature of Urban running, there are not very many formally organized races, and most are not sanctioned by a sanctioning body.