Francois d'Haene winner of the 2013 Ultra race. Photo: skyrunning.com

For many years it seemed like running 26.2 miles in one hit was was more than enough for most people. For armchair runners it was almost superhuman. Nowadays you can’t help but be overwhelmed by the amount of marathoners there are out there. Every man and his dog seems to be entering one for charity.

The rise in popularity of the marathon over the past few decades has led to the natural search by runners looking for the next big challenge. And so the ultra distance race has become the yardstick to measure yourself against others by.

Strictly speaking an ultra is anything longer than a marathon which that can mean anything from 50km right up to 200miles. Difficulty depends on the terrain depends on the terrain and conditions as much as the distance.

Here is a selection of some of the toughest of their kind in the world right now.

Marathon de Sables

Distance: 154 miles

Photo: Marathon de Sables

This is one of the biggies. It’s been running since 1986 and since it’s inaugural year with 23 competitors has blossomed into one of the most high profile of the big challenge races. Some stretches of the sand as so fine that the run actually becomes a trek. Avoiding mid-summer temperatures by running the race in April helps a bit but temperatures regularly get up to very high 30s.

www.marathondessables.com

Jungle Ultra

Distance: 143 miles

Photo: beyondtheultimate.co.uk

The Peruvian jungle is the home of this ultra. The route descends from 3200 metres down through the cloud forest and into the Amazon proper. It’s a stage race but all racers are self-supported and expected to carry all supplies and a hammock to sleep in. Only water is provided at the various check points.

www.beyondtheultimate.co.uk

Badwater Ultramarathon

Distance: 135 miles

Photo: Badwater Ultra/AdventureCORPS

Melting shoes, ice water baths and the running from the lowest part of the continental US to it’s highest part in one uninterrupted 135 mile stint put this up there. Running the race during the hottest month of the year in July adds a somewhat unnecessary level of pain.

www.badwater.com

Spartathlon

Distance: 153 miles

Photo: Spartathlon.gr

Dreamt up by members of the RAF to see if was physically possible to cover the 153 mile distance between Athens and Sparta in Greece in the 36 hours it took Athenian messenger Pheidippides to make the journey asking for help in the battle of Marathon (where the 26.2 miler got it’s name). Apparently it is possible and each September racers cover the pleasant terrain under a deeply unpleasant time limit. Nobody mentions the fact the Pheidippides died shortly after making the run himself.

www.spartathlon.gr

The Iditarod Invitational

Distance: 1000 miles

We're not sure you get to slide on the sleds either. Photo: Mike Curiak

Held along Alaska’s famous Iditarod trail during the famously harsh Alaskan winter, runners cross the tundra either on foot or by bike and have to be self supported. To qualify for the full distance race, you have to have proved yourself in the shorter 350 mile race the year before. Needless to say, running in an Alaskan winter is a bit chilly never mind dragging a sled behind full of your supplies to keep you going in vast wilderness.

outsidetimes.com

Want more? Here are 10 of the world's most hellish races.