The science is in and it's scary. Sitting down is bad for you - very bad. So much so that some workplaces are starting to act.
The time has come for office chairs to come with a health warning and ''upholstered, height-adjustable weapons of mass destruction'' might not be too much an exaggeration.
Sitting for prolonged periods - and, let's face it, few places compete with the office when it comes to opportunities to park one's behind - is now linked to increased risk of premature death, particularly from cardiovascular disease. It is also associated with increased risk of developing type 2 diabetes and cancer.
What's more, these risks are not necessarily mitigated by those few hours a week you might spend running, swimming or pumping weights at the gym. That kind of exercise is still important, so don't stop, but sitting for prolonged periods appears to be a health hazard itself, much as smoking is a health hazard even if you also happen to be a devoted jogger.
The science is scary and has prompted some bosses to re-think how they make their office staff work.
Some of the most recent findings come from an Australian study published in the journal Circulation in January. It found that for every hour that a person spends sitting in front of the television, their individual risk of death from all causes rose 11 per cent, their risk of death from cardiovascular disease rose 18 per cent and their risk of dying from cancer, 9 per cent.
Professor David Dunstan, of Melbourne's Baker IDI Heart and Diabetes Institute and the paper's lead author, is keen to emphasise that the research is not about TV watching per se but about sitting, wherever it might be. ''Television viewing time is a reasonable indicator of a person's overall sedentary pattern,'' he says. "Modern society has come to mean a lot of us simply shift from chair to chair throughout the day: seat in the car, the office, the couch at home.''
Several medical research bodies - including Sweden's Karolinska Institute and, in the US, the University of Missouri-Columbia and the Mayo Clinic - have been looking into the specific mechanisms that link time spent on one's bum with poor health. One is obvious and well-known: fewer calories are burnt, you get fatter and there are health consequences.
The other is more insidious. It seems that muscle contractions - even very small ones such as those required to keep us standing upright - trigger important processes to do with the breakdown of fats and sugars. When we sit down, those muscle contractions cease and the processing stalls. The good news is they restart shortly after we stand up again.
"You increase your metabolic rate between 10 and 20 per cent above resting simply by getting up off your bottom - not walking anywhere, but simply standing up,'' says says Dr James Levine, professor of medicine with the Mayo Clinic.
''And there is a whole cascade of metabolic [phenomena] that are activated within two minutes, perhaps sooner, of getting up and bearing your own weight. That cascade involves insulin receptor activation, lipo protein lipase [an enzyme that helps break down fat] activity and more. And these things are deactivated within several minutes of getting down off your legs."
The value to human health of prolonged but low-level movement is vastly underestimated, he says.
Last year, Baker IDI and the cancer prevention research centre at the University of Sydney measured the amount of time people with sedentary jobs spent sitting and found that office, call centre and retail employees spent 77 per cent of the day seated. That's 31 hours a week planted on a chair for an employee working a 38-hour week; 46 if working a 60-hour week.
In a booklet titled Stand Up Australia, published with Medibank Private, they recommended that employers: consider sedentary time in their occupational health and safety policies just as they do seating posture; audit levels of sitting among staff; and "explore opportunities to reduce sitting in the workplace". And there is the challenge: reducing office sitting time while maintaining productivity.
Professor Dunstan could easily spend far too many hours on chair each week himself but he doesn't.
"I've introduced a stand-up desk into my work routine,'' he says, ''and I have become conditioned to being able to stand for a predominant part of the day. And I don't stand still.''
Professor Levine has taken on the movement challenge in ways both big and small. ''I have a two-metre-long curly cord between the telephone and the handset, so I'm able to just pace around as I talk to you, looking out at the freezing snow of Minnesota,'' he tells the Herald.
He has also been heavily involved with the design of the Steelcase Walkstation, a treadmill desk at which one can use a computer, talk on the phone, read etc, all the while strolling at a sedate two-or-so kilometres an hour. Levine uses one himself and has introduced them (and stationary bicycle desks, too) to a range of workplaces, mostly in the US.
Roger Highfield, the editor of British New Scientist, trialled a Levine-style treadmill desk when he was science editor for London's Telegraph newspaper. He was, he says, ribbed mercilessly by colleagues but after six weeks had lost 1.5 kilograms, having made no other lifestyle changes. After 12 weeks, his "sense of wellbeing had surged and energy levels were at an all-time high''.
Unfortunately, he had to get rid of it once he had written his story about the experience. There just wasn't enough space in the office.
''A treadmill is a relatively big and expensive piece of kit,'' Highfield says. ''And there's a certain amount of aggro to be endured in adding a PC and a phone, plus headset. So, unless the management buys into the idea, it is not really going to happen, alas. And health and safety would probably come up with a reason to ban treadmill-cum-offices, too - eek, you might fall off treadmill with phone wrapped around your neck etc.''
Dr Mary Wyatt, an occupational physician, shares a treadmill with colleagues at her Melbourne consulting rooms. They don't have a computer rigged up over it, Levine-style, but use it while making phone calls or dictating reports or just to take a break. Wyatt thinks it's great but understands why some employers might hesitate.
''If you're talking about a substantial number in the workplace then you're talking about a decent cost. You're walking at a pretty slow speed but people can still fall off. Employers are very fearful of work injuries … and, I don't mean to be cynical, but I can see some employers wondering what's the benefit for them of preventing heart attacks that might only arise in 20 years.''
Even Levine agrees that treadmill desks and their ilk are not the only way to approach the issue. ''Some people simply won't use one, just as some people will not go to the gym,'' he says. ''What you need to do is to create an overall environment of health.'' Levine is now in the midst of a research project involving four large US companies that will attempt, among other things, to quantify the dollar value to employers of these sorts of movement and health interventions. A pilot study has indicated that there would be indirect savings in terms of preventing future health problems but also direct productivity and profit increases, thanks to increased staff energy, reduced absenteeism and the like.
If a solid return on investment can be proven, then perhaps more of us will wind up strolling through our days at the office on a treadmill desk rather than perched, static on the outside and stagnating on the inside, on an upholstered, height-adjustable health hazard.
