No wonder we're dying from being deskbound

According to Professor Marc Hamilton of the University of Missouri, sitting at a desk for hours on end is as insidious to your health as smoking or over-exposure to the sun.

And the health risks increase if your idea of relaxation after a hard day's toil is to sit in front of the TV watching Corrie. We should all be taking more exercise. But when?

Batting aside the vexed question of precisely what is not bad for your health these days (breathing? Not if you're standing upstream of London's pavement smokers), this latest news cannot be any surprise to the legion of Londoners shambling stiffly home.

Even without this pronouncement by Professor Doom, a quick inventory of those stinging eyes, aching shoulders, stiff joints and KitKat-induced spare tyres should be indicator enough that the human body was not designed to spend all day in front of a PC.

Offices are horrible. If you don't agree, you must either work from home or be an executive who has chosen his own furniture. An average day in our office, the alluringly named room 225b, goes something like this: 9.30am: "It's boiling. Can we turn the heating down?" 10am: "It's freezing. The heating must be broken." Midday: "Something's just bitten me." 1pm: "I'd better grab a sandwich, but I feel sick from looking at the screen."

1.08pm: "Anyone got a cloth? I've spilt some soup on the keyboard" 2.15pm: "Anyone got some eye drops?" 3pm: "Anyone got a Nurofen?" 3.45pm: "I NEED SOME NATURAL LIGHT, NOW" 3.46pm: "Bollocks, it's dark again."

Our office is perfectly pleasant, with chairs so sophisticated they almost make their own tea, but even the nicest office drains the life out of you.

Faced with so much prescribed inertia, it is amazing what women, ever terrified of getting fat, will do to compensate. I once worked with someone who stored an exercise ball in the fashion cupboard, while another colleague was obsessed with T'ai Chair, a sedentary routine that involved nothing more exerting than shoulder rolls.

I walk as much of the way to work as time permits, arriving in trainers with my heels stored in my Downtown. Other than this, all I do is jig my right leg, a tic I've had since childhood and was embarrassed about, until I read it burned 50 calories an hour. Tragic or what?

With Britons already working the longest hours in Europe, the last thing our sedentary backsides needed was an addiction to the F-word. Not the rude one (at least that would burn more calories) but Facebook, whose UK users have increased by 523 per cent in the past six months. When the most vigorous exercise most of us gets is a poke, it really is time to worry.