Janet Street-Porter: Strenuous activity? Try a country ramble

How much of yesterday did you spend sitting on your backside? Judging by the size of most people, far too long. We accuse the Government of behaving like an interfering nanny when (in the name of good health) it issues guidelines about how many units we should drink a week, how many portions of fruit and veg should be consumed daily, and how much exercise we should take – but now some experts think these guidelines are too feeble.

An expert on the radio the other day was advocating 10 portions of fruit and veg instead of the recommended minimum of five and now sports scientists want us to stop walking and start running if we want to avoid an early grave. The Department of Health recommends 30 minutes of moderate physical exercise at least five times a week which can include walking, mowing the lawn and housework – but doctors at Exeter University have completed a study which advocates "rigorous" rather than moderate activity if we want to avoid heart disease. Not only do they sneer at dusting as a carb-buster, they've even pooh-poohed my favourite activity, rambling.

According to Dr Gary O' Donovan, short bursts of intense physical activity like jogging, or playing sports like football or tennis, are far better for our health in the long run than a regular regime of normal walking. This does reduce the risk of diabetes or heart disease by 50 per cent, but strenuous activities bring more benefit and also reduce the risk of colon and prostate cancer.

In America, health guidelines have already been amended to suggest five moderate sessions or three strenuous bouts of exercise weekly, although there are no plans to adopt that advice here. In his pre-Budget report, Alistair Darling allocated funds to enable every young person to have the chance to participate in up to five hours of sport a week – a bit of a shame then that so many playing fields are being sold off for housing – but he didn't address the problem of adult obesity.

The problem with advocating strenuous activity is that most of Britain can't even walk properly, let alone jog. Every weekend I see people trying to take their government-recommended walk, waddling along in fancy footwear, looking uncomfortable wearing the wrong clothes. Coach-potato Britain can't even put one foot in front of the other and move at a faster pace than three miles an hour as it is, judging by the turn-out at my local branch of Tesco.

Perhaps Sir Terry Leahy could offer incentives like vouchers for anyone who can whizz up and down the aisles and complete the weekly shop in less than 30 minutes. Forget jogging. It's a horrible way to get fit, especially if you live in a town – an opportunity to wreck your knees by pounding up and down on tarmac, wreck your lungs by breathing in clouds of exhaust fumes, and wreck your figure by jiggling your curvy bits about in a really undignified way – and I really don't want to end up with a washboard chest looking like Paula Radcliffe, thanks very much.

The best way to avoid heart disease is walking in the countryside, striding up and down hills at a brisk pace, on footpaths rather than roads, breathing in unpolluted air, enjoying peace and quiet, getting spiritually regenerated by the sights and sounds of nature rather than an arterial road. If you want to see healthy people, check out a group of walkers, straight-backed and firm of limb. Running is full of stress – just another way of avoiding human contact.

Kate Moss – wrinkles and all

Most women can find fault with their skin, but nothing quite prepared me for the pock-marked, lined features of Kate Moss's cheeks. In an act of extreme bravery she has allowed herself to be photographed in merciless detail by the distinguished artist Chuck Close. The resulting image was then blown up over two metres high and turned into an extraordinarily realistic monochromatic tapestry using computer technology, on display this week at the White Cube Gallery in London's St James's.

The face that's sold a million lipsticks for Rimmel looks out at visitors like a sphinx or a nomadic tribeswoman, unadorned and exposed. I doubt you'll see a more affecting image anywhere.

* I nearly choked on my porridge when I read that the Royal College of Nursing had only managed to collect a quarter of the donations promised by highly-paid Premier League footballers. These overpaid wallies had agreed to donate a day's wages in order to support nurses in need via the Mayday campaign set up by the economist Dr Noreena Hertz, in recognition of the care received by her terminally ill mother.

The appeal featured on a Channel 4 programme in June – but the majority of the players have yet to cough up. Teams at Fulham, Reading and West Ham have made their contributions, unlike wealthy Manchester United where only two players could spare the cash, and none at Chelsea, even though the club sent a donation.

Players earn on average £600,000 a year – whereas nurses earn less than striking postal workers. The Football Association tells us footballers donate generously to charity. Only when the cameras are rolling, if you ask me.