I have just completed my first shift as a security volunteer at my synagogue. My 89-year-old mother (who readers of this column know has moved into our house), my ten-year-old daughter and my wife all seemed – to put it mildly – sceptical about the degree of protection I can afford our congregation.

But I’m thinking I run once or twice a week, so that must count for something. Yes, tectonic plates move quicker but the ratio of 45 to 24 is worth it I reckon. That is 45 agonising minutes for the return of 24 hours of smug self-satisfaction. I don’t get the latter without the former. And I want the latter.

The persuasiveness of this point, which has the intellectual heft of a Tesco ad – 24 apples and only 45p – is what propels me up the banks of Regent’s Canal and then anti-clockwise (so transgressive) around Victoria Park.

This motivational pep talk drowns out the chorus of objection from my every molecule. You think making our lives a misery helps us live longer, they sneer. Yes, I gasp, followed by the clinching evidence of my argument, an ever-increasing roll call of middle-aged peers who have died despite living, as I do, in one if the safest, healthiest countries in the world in a period that is the safest and healthiest in its history.

Actor Paul Ritter, footballer Gianluca Vialli, poet Benjamin Zephaniah are three recent additions to the list, their names spurring me on. I have no idea what they died of, except Rik Mayall, who died of running. And Matthew Perry. I could cry over that one but I’ve done 6K and I can’t afford the breath. Oh look, there’s Israel Zangwill’s house. It has a blue plaque, which is nice. Anything to distract. I am overtaken by a girl in a baseball cap. Her ponytail flows out of a hole at the back, healthily bouncing and swishing with glossy glee like, well, a ponytail. Similes don’t come easy this far round the park.

By peers I mean generationally speaking, not in terms of achievement or fame obviously, I tell the sneering molecules. By 7K I am short-tempered. I particularly dislike being overtaken by people chatting on bicycles. The ill I wish them shocks me.

But who am I kidding? It is not the hope of avoiding an early(ish) death that propels me around the park, it’s the daughters. It is for them that I want to slow my physical decline.

The ten-year-old, who is built like a whippet and is properly fast, has already spotted it. She reckons she can beat me in a sprint and could be right. But the one-year-old is different. I worry she may never have a physically fit father. So I keep going.

She is a great mimic. She replies to my elephantine sneezes with uncannily accurate convulsions followed by giggles. While carrying her up the stairs from the kitchen in the basement to her second-floor bedroom – a climb that reminds me of the running gag in Neil Simon’s Barefoot in the Park where everyone who visits the newlyweds’ garret is too exhausted to speak – the one-year-old sticks out her tongue and impersonates the final stages of a fatal asthma attack.

Then there is the line in Arthur Miller’s The Price, which is set in an attic. “Do you want some water?” the elderly furniture dealer is asked as he enters. He shakes his head. “A little blood I could I use,” he says.

Back around the kitchen table the subject of my impending first security shift prompts ripples of suppressed laughter. It moves like a Mexican wave growing as it travels from wife to daughter to mother, to one-year-old, who squeals delightedly.

“You?”, says the mother, the word dripping with incredulity. “Are you going to protect everyone with that tummy?” asks the 10-year-old. What tummy, I am about to say, but her foot is now buried in it up to her ankle. In the corner my running shoes beckon.