Week number two of my new fitness regime and it's already gone pear-shaped. Week one – buying runners – went well, but week two – wearing them – went horribly wrong. I made the mistake of bringing them to a gym. I'd forgotten what a testosterone-fuelled pit the whole shower area can be. And I'd also packed my sports bag in the dark, selecting from the underwear drawer an item that would have further effeminised a lady boy.

I'd have been safer wearing my wife's underwear, particularly as the other men present seemed to be a group of body-building bouncers from various eastern European countries, many of whom could well have been war criminals. "Don't hurt me, I work in the media" cut no ice here. Nor indeed did the words "mercy", "help" or "hello sailor".

The real mistake I made was thinking I could buy my own underwear. This is a fallacy of mine linked to a belief I still vaguely have that I am an independent person who can survive in the world without adult supervision. Wiser heads than mine believe shopping for underwear is beyond most men, and they are right. "Leave it to your wife," they say, but I am nothing if not old-fashioned.

I thought I knew what I was doing. "How hard can it be to find white kecks with a red waistband?" I asked myself? But it's not that easy in real life. The underwear boxes are vaguely homoerotic and I'm not sure it would reflect well on you to linger over them. I spotted the ones I thought I needed and was just about to pounce when I saw similar ones with a more fetching gold-coloured band. "Ah," I thought, "live a little, what harm can it
do?"

The answer was quite a lot. They weren't the same. The back, an area for which I think the word 'generous' should be used at all times, was more akin to a G-string than a comfortable seating area. The front had been designed during a cotton shortage but made up in dynamic uplift, support and pinpoint definition what it lacked in common decency. "Don't ever wear them out," my wife told me solemnly, "unless you intend to leave me."

I couldn't bring them back. That would have involved me holding them up in front of a beautiful young sales assistant and telling her, "I'm not this type of man." And that would have exposed me to the possibility of her looking at the box and saying, "No, you aren't." I thought of trying to offload them onto a friend but my wife argued it would be too public a questioning of his sexuality. "He'll come out when he's ready," she told me.

So they languished in a drawer until they ended up in my sports bag. I realised the mistake as I sat naked and wet after the shower. Naked and wet and among a group of men who lift weights four hours a day, drink weird protein things and have 'packages' that would disappoint a hamster.

So I took the only option: Commando. Yeah, I know. What must they think of me? Still, they didn't get my name and will remember me only as the 'Commando' guy who can dry himself really, really fast! No, honestly: really, really, really fast.