Dom Joly: Trouble with faking Iron Man is...

Weird World of Sport: It's about machismo and bragging rights – something I totallyunderstand

My brother-in-law takes part in something called Ultimate Iron Man that takes place near where he lives in Costa Rica every year. From his description it sounds like something akin to the entrance exam to the SAS. It's a three-day event with not much time off. In it he runs, bicycles, swims and hacks his way through thick jungle in unbearable heat wearing little more than some sort of glorified thong.

I can't help but be impressed by the fact that he does this but I also can't help hating him for it. There's no rational reason for doing this sort of activity except to show off and to make people like me feel inadequate. Unless Costa Rica (which has no army) becomes a hideous dictatorship and starts to imprison Canadians in ultra-hellish prison camps that he then has to escape from and survive until he reaches freedom, there is no logical reason for training or competing in this sort of event.

It's really all about machismo and bragging rights – something I totally understand – just don't have access to... people who do Iron Man and suchlike are always the annoying types who wander into a situation when you are trying to impress a woman and you suddenly find yourself sitting alone in the corner munching on a large consolatory cheeseburger.

Ages ago, in my 20s, I was very keen on someone and was making fairly good headway until an old "friend" turned up in town out of the blue. He was a physically imposing looking guy anyway but it soon turned out (because he wasted little time in telling us) that he had just completed the "Marathon Des Sables". This, he proceeded to bore us all with, is a six-day endurance race across the Sahara Desert in Morocco. He had photographs, then video footage and we had to listen to hours and hours of this bollocks. It was only at the end of the evening when my target girl disappeared off with this robo-athlete that I realised how attractive this sort of thing is to the opposite sex.

My suspicions as to what drives individuals to attempt Iron Man-type events were pretty much confirmed when I spotted photographs of that screechy, maudlin songstress, Alanis Morrissette competing in one recently. If ever there was an example of somebody trying to escape some personal demon then this had to be it. I'd love to see a Celebrity Iron Man competition – perhaps we'd get Pete Doherty, Robert Downey Jr, Morrissey? It can't be long until that's snapped up by some TV station, maybe they can get all those celebs climbing Kilimanjaro for Comic Relief to do one?

There is, thankfully, a big difference between that type and the sort of people who do a one-off marathon for charity or for a personal challenge. To be honest, they're still a bit annoying but it's not a life fixation for them and they soon talk about something else once they've got the pictures of them wrapped in those weird silver space blankets out of the way.

These amateurs are quite refreshing as they don't make you feel that inadequate with their tales of having to put Vaseline all over their testicles and nipples to prevent "jogger's rash" and vomiting all over the streets when the ordeal is over. You never see any of this on the TV coverage of the London marathon. The nearest you get is a bit too much of Paula Radcliffe than you bargained for.

But if the amateur has to go through all this weirdness, imagine what the lunatic who does it in a rhino costume is like afterwards? I was asked recently to be a celebrity-sponsored participant in the London Marathon by the sponsors – Flora. Fortunately something went wrong with their paperwork, or maybe they found a better quality celebrity? Whatever, they never came back to me and I didn't have to make the decision of whether to attempt it or not.

Anyway, why would I need to do it for real when I can fake it and get the same result? This photograph of me jogging through Death Valley in the Mojave Desert was enough when attached to an e-mail to my brother-in-law to persuade him that I was in the club. The only problem is that he's now invited me over to do the Ultimate Iron Man...

Glasgow's shame: a lack of caber tossing

I'm writing this in Glasgow where I am for the day. I really wanted a go at caber tossing, but having Googled it, there seems to be no training facility for this sport in the city. This is a disgrace.