Megan Singleton looks at some races for the truly diehard. Or the truly mad.
1. Tarawera to Kawarau
Early February
New Zealand plays host to the second extreme event of the year on the Ultra-Trail World Tour every February. This year's has just been, so you've got twelve months to prepare for the next one. Runners can choose to relay a mere 65km, 80km or 100km across our striking landscapes. One thousand people descend on Rotorua - including 300 from overseas - to run the race of their lives around four lakes, through forest and past waterfalls in this four-day event.
2. Spain
March
In its 12th year, the North Face Transgrancanaria races across the island of Gran Canaria and now attracts about 2500 walkers, runners and nature lovers who think nothing of a 100km walk to smell the roses - or whatever it is they smell on this Spanish island. They must be done in under 30 hours through rain, sun, mud and dust - so it's not just the elite who can compete. They also promise the course will be well signposted with plenty of aid stations.
3. Australia
May