What has my friend Madonna — I write about her so often that I feel I know her, like a stalker — done to her arms? More to the point, why? And why was Nicolas Sarkozy out jogging in public with his wife Carla before he collapsed?

You’d think some folk would reach a point — world domination, mighty chains of office — where they felt they could set the pace and take a breather from keeping up with lesser mortals.

I know my idea of heaven isn’t necessarily other people’s, but I still find it weird that not a single female celebrity I can think of has embraced middle age gleefully, hurtling towards smocks, comfy shoes and thirds for supper, shunning Botox and the scalpel, laughing hysterically at the mention of diets before helping herself to another piece of fried chicken.

It can’t be lack of desire — what person, having spent what must feel like a lifetime starved and primped in the public eye, doesn’t secretly quite like the idea of lying there surrounded by cake?

Self-control is good, obviously, and no one will forget Helen Mirren in a bikini. I salute her. And it’s not as if I wish everyone would end up like Elvis, dying on the lav after one deep-fried peanut butter jumbo sandwich too many. (Although, if we’re to give the man his due, he knew where his appetites lay and when it was time to give in to them.)

Madonna, 50, and reputed to spend up to four hours a day in the gym, now has arms that remind me of the flayed corpses exhibited by Gunther von Hagens in his Body Worlds show. Sarkozy, 54 — his former supermodel wife is 40 — looked less like a virile he-man and more like a prat when a run round Versailles last week resulted in him being airlifted to hospital. The president’s love of jogging has been described as a “mania” and it’s not hard to read all kinds of not very macho, human anxieties into his desire to be seen as quite so sportif.

But the problem is that when men of a certain age start prancing about in groovy tracksuits, or modelling for topless shots with guns or big fish, as per Vladimir Putin (is he aware of Tom of Finland’s oeuvre: homoerotic drawings that glorify ultra- macho outdoor pursuits, accessorised with huge penises?), the automatic reaction is not admiration, but pity.

Why does he have to try so hard, you ask yourself. What is he over-compensating for? You see them in the gym all the time: normal men do normal workouts, which is all well and good, but there’s always some slightly cheesy bloke aged between 50 and 60 going for the hard stuff — and, usually, falling off the insanely inclined, insanely resistanced treadmill, lying there like a beetle, legs in the air. There used to be a kind of man who, hair weave in place, whizzed around in his big red Ferrari winking at pretty girls. He still exists but now probably jogs obsessively, too. Topless.

I can’t pretend I don’t find gym culture baffling, although I do try to engage with it occasionally. It seems to me that, in gyms, you have two types of creature: the good-looking young, who are good-looking because they are young, not because they go to the gym; and the less good-looking middle-aged, who are trying really hard to be as good-looking as the young. Which will never happen because they’re not young any more.

It’s pretty weird, really. Poignant. The average fiftysomething, we learn, is healthier than the average 25-year-old, who consumes more calories and exercises less often. A spokesman for Herbalife, which conducted a survey of 4,000 Britons aged between 16 and 80, said: “It seems that many young people are underestimating the benefit of a more balanced, holistic approach to diet and lifestyle. It’s great to think that the older generation are showing the youngsters the way when it comes to healthier living.”

Is it? Obviously it’s marvellous that people should not embrace infirm old age a couple of decades before it arrives. But I’m not so sure about the devotion to physical culture. If older people are wiser, why are they not wise enough to know that you can’t hold back time?

You can inject your face up to a point, because it’s good to stop before you start looking like an alien; you can do things with scalpels (ditto); you can spend all day at the gym and get flayed-looking arms, but it all makes you appear more vulnerable, not less. Nobody’s fooled.

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