Matt Butler: You don't have to be crazy, but madness just runs into the sands

What constitutes crazy these days? Not wacky – Usain Bolt has that market well and truly cornered after his dancing to The Proclaimers and donning a tartan bonnet following his 4x100 metres win at the Commonwealth Games on Saturday – but truly addled.

Tom Burridge, the BBC's Madrid correspondent, offered the hypothesis that running over 150 miles in the desert sounds like grounds for needing your head read.

He was one of four runners featured in the first of a five-part series on the BBC News channel on the Marathon des Sables, a 156-mile, five-stage race in the Moroccan desert. As Will Squier, one of Burridge's cohorts put it: "Am I mad?" Andy Cottrill, another of the quartet, added: "I don't even like running."

The MdS bills itself as the toughest foot race on earth, which is a highly contentious label. It is obviously hard, but Orkney Islands native William Sichel, a multiple world-record-holding ultrarunner who, in the next day or so, is set to finish a 3,100-mile race around a New York City block, may have something to say about which is the most arduous ordeal.

That's not to say that the people who entered the MdS are not dedicated – if a little, erm, different, to the bulk of the population.

Burridge offered little answer why he and his three friends were attempting the race, other than to say he wanted it to be "a small moment in my life where I do something slightly radical – to push myself to a point where I have never been before". Perhaps there is no simple reason to run it. Maybe it is best explained with the Edmund Hillary rationale: "Because it is there."

Some of the runners were out to enjoy it. The Japanese man who was running dressed as a cow looked like he was having a whale of a time. And his reason for the bovine garb? "I like cows. I am crazy, I am crazy... mooooo!"

By the end of the second stage, a 26-mile slog over sand dunes in 50-degree heat, cow-man's condition was unknown. But the smiles had been well and truly wiped off the faces of Burridge and his friends. "Two words: reality check," said Cottrill, as he guzzled water. In a nearby tent, Squier, a doctor, winced (along with the viewer) as he performed rudimentary field surgery on his own blisters.

Not long after they had crossed the line at the end of stage two, "Lee", a Briton who looked to be in his early thirties, staggered to the finish with a dead look in his eyes. Doctors swarmed to him, feeding him water while he stared off into nothing, unable to even sit up straight.

Burridge reported: "Lee was airlifted out. He had multiple organ failure and in a coma for a week." Harrowing enough. But then he added: " Lee is now fully recovered and plans to run the event again."

Crazy? Neither Burridge or his mates were game enough to call him so. Maybe in the desert, among 1,000 runners, many of whom who had admitted their "madness", all this suffering seemed normal.