Ultramarathons, or ultras, are any running races beyond the standard marathon distance of 26.2 miles (or 42.2k). The most common ultra distances are 50k, 100k, 50 miles, or 100 miles, but each event is unique in terms of distance and terrain. The International Association of Athletics Federation recognises world records at ultramarathon events that have a distance of 100km. There are even 24hr ultramarathons, where the distance is unlimited, or multiday ultras, where the distance can extend beyond 1000km. There are a couple of city-based ultramarathons, but most ultras make the most of the UK's stunning scenery and countryside. A lot of these events go off-road and require trail-running over difficult terrain with steep climbs or along rugged coastlines. The Race to the Stones is one of the UK's best and most popular ultra marathons, taking in 100km of the historic Ridgeway. Or there is the famous Dragon's Back Race, which takes place over 5 days, taking runners from North to South Wales and requiring ascents adding up to twice the elevation of Mount Everest.
