Ultras and sky races
It is commonly held that an ‘ultramarathon’ (or ‘ultra’) is simply a race over a distance longer than a standard marathon, but there are several governing bodies that have their own definitions of ultramarathons. The outline below expresses the general ideas behind these definitions.
In general we should think of an ultramarathon as a race that takes significantly longer to do than a marathon, whether because of distance or other factors. Taking the emphasis off distance and putting it onto time gives a better representation of how much commitment and race management it takes to complete one of these races.
Please note that the surface is irrelevant. There are numerous ultramarathons that take place on the road and track. This discipline is not just for trail junkies!
Criteria for ultramarathons
Specifically, we can say that a race qualifies as an ultramarathon if it meets one of these criteria:
- Distance: it is over standard marathon distance (42km / 26mi).
- Elevation (i.e. vertical climb): if the distance is less than a marathon then it has an elevation of at least, say, 2000-3000m. For instance, the Lewes Moyleman (42km/1000m elevation) would not qualify, but the Snowdon Skyrace (38km/3300m elevation) would.
- Time: if the distance is less than a marathon then it takes at least 6 hours for the winner. This is quite often a consequence of elevation gain combined with technical difficulty.
Ultramarathons classified by distance
There are three generally recognised distance bands in ultramarathons:
- Short: 21–41km (13–26mi)
- Long: 42–80km (26–50mi)
- Ultra: longer than 80km (50mi)
Backyard ultras
In a ‘backyard ultra’ runners must complete a loop of 6.7km (4.2mi) – called a ‘yard’ – within an hour as many times as they can. This pace equates to 100 miles in 24 hours. The winner is the runner who can continue completing one yard per hour for longer than anyone else. These races are ‘ultras’ in the charitable sense that the winner almost always ends up by running more than a marathon distance. For more details see https://en.wikipedia.org/wiki/Backyard_ultra.
Governing bodies
The main governing body for ultras is the International Trail Running Association (ITRA). Anyone who participates in an ITRA-registered race is allocated a personal page where their results are listed. You can find any runner’s personal results page by going to https://itra.run/Runners/FindARunner.
Sky races
Sky races are generally not ultramarathons but shorter, harder races with extremely steep inclines/declines. Some involve some graded scrambling. They are not as ubiquitous as ultramarathons and harder to get to.
Technically, ‘skyrunning’ is defined as a sport of mountain running above 2,000 metres (6,600 ft) where the minimum average incline is 6% over the total distance and at least 5% has an incline of 30% or more, but where the climbing difficulty does not exceed II grade UIAA. Poles, crampons, and hands may be used to aid progress.
There are various types (or ‘disciplines’) of sky running:
| Discipline | Distance | Vertical climb (minimum) | Extra info |
| Sky | 20–49km | 1,200m | – |
| SkyUltra | 50–99km | 3,000m | Under 16 hours finishing time |
| Vertical | max 5km | 800m | Minimum average incline must be 20% and 5% of the total distance must be over 33%; double or triple Vertical are also considered |
| SkySpeed | max 500m | 100m | Minimum of 33% incline |
| Stair Climbing | 100m | Races with an incline of over 45% on stairs indoors or outdoors |
More detail as defined by the International Skyrunning Federation (ISF) can be found here: https://www.skyrunning.com/rules/