Your chair is the new health enemy. Sitting has joined well-known foes such as cigarettes, obesity and alcohol as a villain which leads to death and disease.
Some have called sitting the new smoking but really it is more akin to sun exposure — a little bit is actually good for you, too much and it can be deadly.
Where exactly we cross the line into too much is still a bit hazy and requires more research. What is known is that as you pass seven hours a day of accumulated sitting the risk of premature death rises markedly for every extra hour.
And we can’t rely on exercise to negate the risk. Sitting is an independent risk factor for chronic disease, separate from too little physical activity. So even if you tick the box on the exercise guidelines, sitting for long periods will still ratchet up your risk — an effect known as the “active couch potato” phenomenon.
With Australians spending on average nearly 10 hours a day on their behinds, it is a recipe for disastrous levels of chronic disease. Type 2 diabetes, coronary heart disease, obesity and some cancers have been linked to excessive sitting.
David Dunstan, head of the Baker IDI Heart and Diabetes Institute physical activity laboratory, said when people sat for long periods blood flow was reduced throughout the body and muscular contraction — important for regulatory processes including clearance of blood glucose and blood fat — was limited.
After 14 years of researching sedentary behaviour, Associate Professor Dunstan believes the key to reducing risk may be to break up sitting time at regular intervals. A better understanding of the biological mechanisms that underpin the links between too much sitting and chronic disease was a research priority.
Professor Dunstan was part of a UK-commissioned international working group that last month released the first consensus statement outlining guidelines for office workers recommending they accumulate two hours of standing and light activity, increasing to four hours a day during the working day.
Trevor Shilton, the national lead for physical activity with the Heart Foundation, said addressing the nation’s love affair with sitting, and its dislike of physical activity, was an urgent health issue.
“We need a funded national strategy to deal with it … and it will need a whole community approach to turn it around,” he said.
A campaign to encourage Australians to sit less was launched last week. Get Australia Standing is the brainchild of Gavin Bradley, who last year started Get Britain Standing, which for the first time brought together all the science on sedentary behaviour.
The key target for change was the workplace. Mr Bradley’s goal is for 90 per cent of office workers to have access to sit/stand work stations within 20 years.
“There are certain tasks done better and more quickly while standing,” he said.
“Going through your inbox, going through routine tasks, you are more positive and alert and generally more collaborative and so just want to get things done.”
If the task required deep concentration, such as creative writing or analysing figures then that was better done sitting.
But sit/stand desks were not the entire answer.
“It’s not all about having funky equipment, a lot of it is about culture within an organisation. That it’s OK to have a walking meeting, it’s OK to stand while on the phone or have a standing area where people can use their laptops at a different height away from their sit desk,” he said.
“It’s a journey that you can start with zero money, it just needs leadership.”
He said as the message about the risks became better known companies would have no excuse except to address it as part of their occupational health and safety obligations.
Why we need to sit less and move more
- Sitting for eight hours a day increases your risk of diabetes, heart disease and cancer by 40 per cent.
- After 90 minutes of continuous sitting your metabolism slows down: lipoprotein lipase, enzymes that break down fat, slow down by 90 per cent.
- People considered to be “high sitters” have double the risk of developing heart disease and type 2 diabetes, a 13 per cent increased risk of cancer and 17 per cent risk of mortality compared with “low sitters”.
- Every additional hour of television viewing per day is linked to a 10 per cent higher risk of developing type 2 diabetes and a 7.5 per cent higher risk of developing cardiovascular disease.
- For those who sit seven hours a day, every additional hour of watching television adds 5 per cent to their risk of premature mortality.
- The more people sit at work, the more likely they are to sit at home.
- When standing you burn 50 more calories per hour than you do while sitting.
- Even people who meet the physical activity guidelines for exercise can rack up long sitting times and be vulnerable to the associated risks.
Sources: getaustraliastanding.org, expert statement on the sedentary office published in the British Journal of Sports Medicine, Baker IDI Heart and Diabetes Institute physical activity laboratory head David Dunstan, Heart Foundation WA –
