There comes a stage in the lives of even the least sporty of all of us when it is hard to ignore the need for regular exercise.
I have been waiting, for longer than I would care to admit, for medicine to come up with a small key that we could insert into our side, at about hip height, and give our stomach muscles a gentle tightening. It would mean an end to all that breathing in that men in particular indulge in when they are taking their clothes off. But it remains a pipe dream, and now my waistline's svelteness is going the way of Lord Lucan - disappearing without trace.
So, to the swimming pool. To make it more than a purely physical experience, I selected an integrated pool, fully accessible to all, whatever their abilities. I hoped that swimming with people who daily transcend daunting physical disabilities might stop me fussing about looking like Winnie the Pooh when I wear a red T-shirt.
Being in such an integrated environment has also cast new light on other cherished notions. Anyone who reads this column regularly will know that society's continuing failure to look beyond people's disabilities to their abilities usually has me diving in at the deep end.
But as a member of the the pool community, I have been forced to realise that the problem is more complicated. One of my fellow dippers is a wheelchair user and has been complaining of late because the organisers won't designate certain sessions 'disabled only'.
We've had a good few talks about it. It turned out he disliked the able-bodied swimmers trying to beat Ian Thorpe's world records and causing minor tidal waves in their wake. "They make it too hard for people like me," he patiently explained, showing how his balance is often more fragile than mine. We were watching one of the worst offenders when the chap in question sped over to the side in a flurry of splashing and - yes, you've guessed it - hauled himself into his pool chair and wheeled off to the changing rooms. Stereotyping cuts many ways.