A marathon is no longer enough to inspire some runners, with the desire to push themselves even further and often in extreme conditions providing an unavoidable allure for those with a certain mindset.
Some are raced in heat, some in the cold. Others take competitors repeatedly through cities or over mountains or across isolated outback.
There is something for everyone looking to prove themselves in the harshest conditions possible as they aim to push both their physical and mental boundaries.
1) The Barkley Marathons – Tennessee – USA – April
Imagine running five laps totalling over 100 miles around the wilderness of Tennessee, including 120,000 feet of climbing – and that’s if it all goes to plan.
Known as ‘the race which eats its young’ and created by the almost mythical pair of Gary’ Lazarus Lake’ Cantrell and Karl Henn, the start of the Barkley Marathons is signalled by the former lighting a cigarette, with competitors having 60 hours to complete the course.
Only 35 entrants are allowed to enter each year, all of whom receive a letter of condolence, with just a handful of runners completing the course since it was first held in 1986.
2) 6633 Arctic Ultra – Yukon Territory, Canada – February
Starting in Canada’s Yukon Territory, competitors intend to make it through to what must feel like the end of the world.
Both 120-mile and 380-mile courses are offered, the latter finishing in the hamlet of Tuktoyaktuk along the banks of the Arctic Circle, with those involved encountering heavy blizzards, icy winds and temperatures that do not even get close to freezing.
The views may compensate for some of the hardship, but it would be unwise to stand still for too long in such conditions!
3) Badwater 135 – California, USA – July
‘Running on the sun’ is how the Badwater 135 has been described, with the course covering 135 miles non-stop from Death Valley, the lowest elevation below sea level in North America, to the Mount Whitney portal.
That ascent’s summit was previously the finish line but the route changed after organised events were banned from taking place on national park land.
The event includes a total ascent of 14,600 feet, with much of the race run in unrelenting average temperatures of over 45 degrees centigrade.
With stretches of the course known as Furnace Creek and Devil’s Cornfield, the 80 per cent of starters who complete the Badwater 135-mile-long route within the 48-hour limit literally deserve a few days of chilling out.
4) Self-Transcendence 3,100 Mile – New York, USA – September-October
While other races on this list are compensated by the sweeping views that can mesmerise and distract their competition, the Self-Trancendence 3,100 Mile certainly does not.
Staged in Queens, the route is simple: competitors have from 06:00 to midnight to run an average of 59.6 miles per day for 52 days.
Originating in 1997, the race hardly offers challenging terrain, as the 3,100 miles are run around the same route around the New York borough of Queens.
The volume of distance terrifies most runners, but the psychological tedium gets the rest, with those who finish often persevering due to their pursuit of a greater meaning.
5) Ultra Trail de Mont Blanc – Chamonix, France – August
Held every August, the Ultra Trail de Mont Blanc, or UTMB, is seen as the pinnacle of European ultra running, with participants having to collate enough qualifying points from other races to even have a chance of earning a place on the start list.
The race starts and ends in Chamonix and is part of a week-long running festival involving routes of different distances. However, the mystique of the flagship 106-mile UTMB is what attracts the world’s best.
The route features sections in France, Italy and Switzerland and, while the photographers get some fantastic images of those running through the mountains, the runners barely get to enjoy their surroundings as rather than looking around, they are usually only gazing up!