IWAS asked to write this fitness column out of spite. I know it.

They sat in the office, they who make the decisions, and they decided to choose the least fit person in the building to fill in for Ros Dee.

Probably thought they were being playful.

Mischievous. They were wrong. It hurts.

I spend my life trying to run away from my guilty secret. But, like a sprinter on a treadmill, it's a somewhat fruitless exercise. (Oh exercise! It pains me to say the word. ) Because there's no getting away from it.

Fitness is everywhere, flaunting my unfitness in my un-toned face.

It starts in the morning, when I drag myself out of bed and peer through the window into the rain and cold. A day for the bus, you might think. But no.

Women in trainers powerwalk by, stillettos cradled in punctured-looking plastic bags. Unidentifiable people wrapped in raincoats and rain-trousers peddle their bikes past half-empty buses, heads grimly bent against the elements. Then there's the joggers. Don't talk to me about the joggers. I dress, warmly and half-heartedly, and consider dragging my bicycle out the door.

But immediately a team of excuses sprint into my mind, tackling all exercising thoughts to the floor, winded.

The rain is an obvious obstacle . . . my hair would get frizzy(er). Then there's the matter of the mild cough I've been struggling with.

What of my very loose plans to go to town after work . . . my bike might be stolen. Best not to chance it.

One blissfully inert bus journey later, I arrive to work and settle down to read the paper, carefully avoiding the health supplements, where one regularly finds talk of heart disease and cholesterol and 'regular exercise'. Regardless of these efforts, I always get suckered with a fitness punch. It's everywhere. Celebrity fitness, child fitness, post-pregnancy fitness and, just when you think you're in the clear, fitness for the over 80s.

Then there's always the exercise regimes for busy women.

How to do squats while making a cup of coffee, how to do butt-clenches while on the bus, the benefit of calvestretches while sitting on the toilet. Never safe.

Following this distressing trip through the paper, I relax until it's time to leave the office again in the evening. The evening.

My most hated time of day.

Everyone has 'a class' or 'a game' to go to. Yoga, Pilates, judo, aerobics, kick-boxing, boxing, football, rugby, tagrugby, hurling, track. I sneak home for dinner. Pretend it's not happening.

Then they ask me to write about it. Those people who make the decisions. Expose my guilty secret. Cruel.

Of course, I wasn't always like this. No, no. Just two years ago, I was a veritable 'gym bunny', hopping from machine to machine, pumping iron. All rippling muscles and flexible joints was I.

Squatting up and down with my big exercise ball before lithely throwing myself into position for a few hundred sit-ups.

I still remember my first visit to the gym, when I campaigned for the 'dumbbell' to be called a 'smartbell', because it's always nice to be nice. Even to an inanimate object. Although, when I got my hands on those smart-bells, they were never inanimate.

Flying through the air with one flex of a bicep.

People actually asked me for exercise advice back then.

When I had nothing to hide.

What happened? We moved away from the gym to a different side of town. It never occurred to me to search the local 'fitness centres' for a replacement.

The loss was too intense. I had found The One. I didn't want anything else.

As if sharing my grief, my trainers grew old, and worn.

I couldn't bring myself to leave them for a younger, fitter version.

My tracksuit, on the otherhand, was fine. No excuses there. But without the gym and trainers, it seemed to somehow shrink.

Each time I wore it, it clung tighter and tighter. As time passed, I felt it was best not to put us both through the emotional turmoil.

Which brings us to the present, in which I'm forced to live. A loner, in this world of exercisers, ever guilty with my terrible secret.

Time to come out, I think.

Hello. My name is Sarah McInerney. I'm a nonexerciser. I haven't exercised in six months.

They forced me to write about it, those people with a skewed sense of humour. It's the first step of 12 I think.

Don't know if I'll make it.

Twelve steps. Not used to all that walking.