Hongkonger Law Chor-kin prepares to tackle Death Valley's Badwater Ultramarathon

Sometimes you wonder if Law Chor-kin is really human. Though known for his extraordinary running exploits, Law's latest efforts have been excessive, even for him.

In February, he ran 298 kilometres in three days on less than six hours sleep. Three weeks later he traversed 100 kilometres in Nepal's Annapurna region, and then managed the same distance again a week later on Lantau. Last month he ran 114 kilometres in 12 hours - on a treadmill. Now he's tackling his biggest challenge yet.

Imagine running more than five marathons back to back. Now imagine running those brutal, thigh-thrashing kilometres in an oven, slow cooking at around 50 degrees Celsius, while climbing the equivalent of almost half an Everest.

Welcome to the Badwater 135 Ultramarathon, the "world's toughest foot race", alternatively known as the "Race Through Hell".

Law, 36, will join 87 other diehard runners in the 36th edition of the race starting tomorrow in the appropriately named Death Valley in California. An invitational race, runners are hand-selected by a panel each year. Even after gaining entry and preparing their bodies for months on end, only two-thirds of competitors usually make it to the finish.

"I don't think there's a thing about this which is good for the body," says race co-ordinator Ben Jones in the 1999 documentary about the race, Running on the Sun.

"Badwater is physically difficult because you have to tolerate the environment."