ONE short sentence and it has altered me, turned me into someone I no longer recognise. The sentence was this: the first 20 minutes are torture.

Why, in 15 years of trying and failing, has no one ever told me that the first 20 minutes are torture? Running, of course, I'm talking about running.

Running is my nemesis. I publicly declared in 2016 that I would never run again.

I made an excellent fist of sticking to my heartfelt resolution but here's the thing: I find it impossible to quit something before it's finished.

One such something was the Couch to 5k app. A flaming, pungent monolith of challenge blocking every attempt to move on with my life.

"You started but you did not finish," I'd hear it whispering to me in quiet moments when I was on the sofa with a scoop of Ben and Jerry's and a slice of Gorgonzola.

"I'm no quitter," I'd reply, demonstrating the truth of the statement by finishing the tub and the block entire.

It niggled and niggled, I couldn't let it lie. And so, a new Couch to 5k app was downloaded, this one shinier and new.

Four running coaches were offered to see novices through a nine week programme. I toyed with employing the comedian Sarah Millican.

I’m not convinced Sarah Millican really wants me, or anyone else, running 5k. I think Sarah Millican, with her Northern common sense, would prefer I had a nice Singing Hinny and a canny cup of tea.

Instead, Michael Johnson assumes the position.

Each run begins with the firm and confident and inspiring, “Hello. I’m Michael Johnson.”

What a mellifluous voice. Golden syrup with a little bit of gravel in the bass.

“You’re doing really well,” he'd sooth into my headphones. I believed him. I was doing really well. I was being lapped by geriatrics and toddlers on balance bikes but I was doing it again, putting one foot in front of the other at a speed you could call "brisk" were you being kind.

That was when I was bold enough to run in the hours of daylight. Often I'd go out at midnight under cover of darkness. Night running has the dual benefits of hiding one's blushes and you'd be amazed at the clip you can build while imagining bogeymen following you along the road.

I built up to running for 20 minutes at a time. “Start slow and steady, build pace with time and get into a nice rhythm,” Michael counselled.

It was tough though. Three times a week? Who has enough spare time to set aside for running three times a week? To do it, sleep was often substituted for more of the night running.

We were up to 25 minutes by this point. “I don’t want to exhaust you.” Oh, Michael. You can have anything you want.

I was exhausted though. It was torture. I'd see running groups and despair at how confident they seemed, how focused.

One Sunday I gave up during the five minute warm up walk and started chatting to a lady on a bench in the park instead. We discussed the recent growth spurt of the signets on the pond, she told me how she likes to wander into people's houses for a nosey and gets away with it due to her advanced years.

All the while Michael urging from the app. I had an offered biscuit and carried on.

I had fallen slightly in love with Michael by this point but it was advice from an article written by a woman who'd recently run her first marathon that changed everything.

No matter how fit you become or how lengthy become the distances you can cover, every time the first 20 minutes is torture.

I just assumed I was useless. I was not useless, I was normal. Running felt awful because running is awful.

Having spent many, many 30 minute sessions mulling over the vast gulf between what I aspire to and what I am, it turns out these two states of being are closer than I'd thought.

I bought a proper sports bra to celebrate.

Eleven weeks on (seriously, who has time three times a week?) and I finished the programme. I ran for 30 minutes straight. It felt... exceptional. There was a definite buzz. I no longer recognised myself. I was one of those smug monsters I've always detested.

Every year I run the Moira's Run in Glasgow's Queen's Park, an event to raise money for The Moira Fund, which supports families affected by manslaughter and murder. I do it because Moira Jones, who was murdered in the park, lived near me and because I deeply admire her mother, Bea.

But it's torture and I usually wear the finisher's medal for a week afterwards because I'm so delighted with myself.

This year's run is on October 28 and this year I'm going for a Personal Best. All those years of scorning runners for their obsession with self-competition. I am now that person. I am a runner. It goes against everything I stand for but there it is.

It occurs to me now that, while I owe him a very great deal, I don't actually know who Michael Johnson is.

Thank you, whoever you are, and I promise to keep on running.