J wants me to go to a body combat class.

"You keep complaining about feeling unfit. Why not do something about it?"

She's become something of an exercise junkie. Wednesday night, Saturday morning, Sunday morning. I am jealous of her energy but too mired in middle-aged lethargy to try to match her. I go walks. I like walking. Every so often I try running but I never stick at it long enough to get past that lung-burning, side-clutching, hacking-your-lungs-up bit to find it in any way fun.

Also, I hate gyms. Hate the liniment and new gym shoe smell of them, that scent of moral superiority. Gymwork is a chore when exercise really has to be fun, but I'm worried that I've left it too long for it ever to be fun again.

Last year The Herald sports desk decided to play five-a-side football. I used to be quite good at football (1). That would give me a workout, I thought, and I'd have fun. And I did. I went along the first Tuesday, took the libero role, ran around, put in a few late challenges, even passed the ball to my own team (2). I came off the pitch thinking that I was still the great undiscovered Franco Baresi of Northern Ireland.

But that night I struggled to take my trousers off. The next morning I struggled to get out of bed. I found myself laughing – actually laughing – at the agony I was feeling.

The next few days the pain that I could feel in every muscle in my body dulled to a muted shriek. So what did I do? I went out and played again the following Tuesday. Well, I say played. I mostly stood around in goals because I had suddenly discovered I couldn't run. I could barely walk. And anything faster than a shuffling jog felt like I had burning coals stuffed inside my skin.

It hurt to run. I did anyway. I put in one accelerated burst – to everyone else I probably looked like a snail on tramadol – and I felt something tear. This burst of pain flared up in my thigh and I swear my eyes started to water. If you can call a Niagara of liquid pouring from my eyes "water". Two days later I slipped in the middle of a forest – ironically while looking for a football pitch (3) – and tore the thigh muscle even more. I didn't think you could feel so much pain. The next day I tweeted the IFA announcing my international retirement.

Those games of football were the last exercise I did. The other day I bent down to pick something off the floor and I felt a twinge in my thigh. I'm now beginning to think I may now have arrived at a point in my life that I'm post-exercise. Pity I'm not post-chocolate too.

FOOTNOTES

[1] Captain of Killowen Primary School football team, 1974-75. Winner of six-a-side intrarmural football tourney, Stirling University, 1986.

[2] At least once.

[3] Long story.

Twitter: @teddyjamieson