So, I confess. I have begun to do something that I have promised myself for all my adult life I would avoid. I have started jogging.
Not jogging in the classic sense, but a programme of running and walking designed to gently break the gloriously unfit back into some semblance of healthy fitness, building up to being able to run a 10 kilometres race.
Well, we have to have a goal, no matter if it is about as far off as never-never land.
Being a good presbyterian, I have three excuses for this back-sliding.
First, as a promoter of sport for young people and as a director of Edinburgh Leisure, which runs the city's sports and leisure facilities, I have come to realise the irony of spending hours in meetings discussing how we encourage others to get active while I can actually feel my own body atrophying.
The second is the arrival of my baby daughter. The seven-year gap between her and her sibling lulled me into a false sense of security about the truth that the smaller the child, the more energy she demands from those around her.
The third excuse is more intractable. Over a year ago, my wife and I sold our car to try to live more simply and get more exercise. Since then, I have reduced my alcohol intake, virtually cut out sweets, started wearing a pedometer and even bought Special K cereal. The pounds have dropped off, but my waistline has stubbornly refused to shift, remaining at about the size of a five-months pregnancy.
When I appeared in a football strip for a photocall for our new girls football development officer (Edinburgh's fastest growing sport), the newspapers printed the one of me lying down with my chin on a ball because the sight of my midriff in a football strip would have upset anybody's day.
The answer, I am reliably told, is that diets are not enough; you need to exercise also. The purveyors of this unhelpful advice usually have swapped their stomach for a washboard, and that's just the women. The men have no discernible paunch and healthy glows on their faces that you would never tire of slapping (excuse my bitterness, but it's just not fair).
Of course, none of this new-found sporting fanaticism has anything to do with London winning the right to host the 2012 Olympics. With fear, parenthood and vanity as my driving forces, the first two weeks of the programme look easy. Walk five minutes, alternate one minute walking, one minute running for 20 minutes and another five-minute walk. Three times a week for two weeks and then it steps up just a little. Just call me Alf Tupper!
How wrong I was. Day one in my newly purchased track suit and trainers began well, with the walk that is. By the second minute's running, I'm hoping I don't meet anyone I know, because I doubt I will be able to talk to them. By the third minute, I am sure a cardiac arrest is imminent. I am loosing the feeling in my legs and they are refusing my brain's instructions in protest.
Day two is not much better. I sweat a passable imitation of Niagara Falls and my assumption that at least I look the part is shattered when I pass some constituents and the two children just start laughing and asking their mum when the circus is coming to town. My legs are screaming about old sports injuries from games I wasn't even playing and I wonder if NHS 24 will be able to cope with my rapidly disintegrating body.
Day three is even worse. My lungs are screaming. That's not a metaphor. I can actually hear them demanding that I stop. I sook my Ventolin inhaler like a crack cocaine addict at his pipe. If Ventolin is a banned substance, the IOC drug enforcement would have a field day.
It's now day four. I still intend to go out and waddle around the streets, but only once I have written this article and done a few more things on my "to do" list, such as fluff the cushions in the living-room and reorganise the screws in my tool-box. Not that I am avoiding the call to jog, you understand, just reprioritising.
I will continue but there is a limit to my "no pain, no gain" worldview. I console myself that those London Olympics that did not motivate me in any way are fully seven years off. It has been an object lesson in why we desperately need more sporting opportunities for young people, and the two hours of PE a week in John Beattie's report. No one should have to go through this pain.
I will not be a competitor in 2012, but my race is more significant - to get fit and fat free before it's too late. That needs to be long before the Olympic flame hits our streets and becomes the beacon of aspiration for young and old we all hope it will be.
Ewan Aitken is executive member for children and families on Edinburgh City Council and education spokesperson for the local authorities.