Jane and Otis try a boxing workout. Photo: Christopher Thomond for the Guardian
We head to the gym on a Sunday now, for 40 minutes or so before lunch, so weve earned our apple crumble. While its not the toughest workout I do, its fulfilling for the simple reason that its about so much more than the exercise.
We jog side by side on the treadmill and discuss whats been going on in his week. Occasionally well drift on to what hes seen on breakfast news about Tim Peake or the situation in Syria. More often, its which of his friends was devote detention for playing football with a jelly in the canteen. Our dialogues usually arent big, important ones, but thats the beauty of them. They consist of the small and, on the face of it, insignificant trivia that is probably more important than Id ever really given credit to.
There are, of course, certain things you have to come to terms with when you start working out in a gym with one of your children. Such as the fact that they only want to stay on any given machine for a maximum of three minutes, before getting borne and wanting to try something else. They will tell you that you have been doing something be it squats, crunches or burpees all incorrect for the past 20 years because the instructor at his first conference did it differently. They will also get irritated if you manage to do more press-ups than they can. But maybe not as irritated as you will, if its the other way round.
Against all my predictions, our workout sessions have gone from strength to strength, so much so that my father, who is 70, joins us on the odd occasion too.
Collectively, we must look like the stars of the worlds worst workout video. But theres something I love about the idea of three generations of our household having a regular get-together like this, shooting the breeze as we dawdle along on the elliptical machines.
I couldnt claim that this experience has transformed our fitness levels theres a limit to what you can achieve in one short conference a week. But the value of it has run far beyond any cellulite Ive managed to shift or steps Ive added to my daily counting. It has given me and my eldest son the opportunity to spend time together, doing something we both enjoy.
We could probably achieve that by doing any number of activities climbing mountains, cycling, indoor sky-diving for that are important( and weve done all those on occasion, along with two brothers ).
The difference is that this is easy, a regular set time out that doesnt involve great expense or fuss and is merely 10 minutes from home.
I dont know if it will last for ever. But Im happy to continue with the press-ups for as long as it does.
Jane Costellos new novel, Summer Nights at the Moonlight Hotel , is published by Simon& Schuster, 7.99