Wake-up to the dangers of sitting

Sitting all day can raise the risk of obesity and metabolic problems.Photo / Thinkstock

A New Zealand health expert says the latest research on the dangers of sitting should be a wake-up call - and simply trading in your ordinary office chair for a more expensive ergonomic model probably won't help.

The University of Leicester study found people at high risk of developing type two diabetes would benefit from being told to sit less and move around more, rather than simply being told to exercise regularly.

The study is the latest in a growing body of research to link prolonged sitting with the risk of developing chronic health problems including obesity, cancer and heart disease.

Medical Research Institute director Professor Richard Beasley, who has studied the link between sitting and blood clots at the University of Otago in Wellington, said the study should be a "wake-up call" about how sedentary our lives have become.

While regular exercise was still important, the study showed the even simpler measure of getting up and about regularly may have a similar effect.

"That's the really encouraging finding from the study," Dr Beasley said.

"Just the simple measure of getting up and about - away from your desk, up from your chair, up from in front of the television or off the computer at home - will also have a significant benefit, similar actually to the exercise."

Dr Beasley's own research has looked at how different types of chairs can affect the blood flow in the legs, where blood clots can develop as a result of prolonged sitting.

He found expensive ergonomic chairs were little different from standard office chairs.

"For most people sitting in offices, it's not the nature of the chair - it's the nature of the sitting," he said.

"We've shown that a wide range of office chairs are very similar in terms of the effects on blood flow. So the expensive designer chairs, the ergonomic chairs, are very similar in terms of the effects on blood flow in the legs as the standard office chair."

Seating which put a lot of pressure on the backs of thighs or over calves did have more of an effect on blood flow, however.

Dr Beasley said the problem was first discovered during the London Blitz in World War II.

"In the air raid shelters, people were sitting in deck chairs and they had a spate of sudden deaths as people were leaving the air raid shelters.

"It was identified that this was due to blood clots forming in the legs, and breaking off and going to the lungs - a pulmonary embolism.

"The team that were looking into this then replaced the deck chairs with just mattresses or bunks, and the spate of sudden deaths went away."

In the modern day, the chairs most likely to put similar pressures on the backs of thighs or over calves were "badly fitting lazyboy chairs''.

But the best advice was still to get up and about regularly.

"The more we're looking, the more we're finding associations between prolonged sitting and ill-health," Dr Beasley said.

"If you're sedentary at work, you have higher mortality, you've got a greater risk of obesity and all these metabolic problems."

The University of Leicester study, published in the diabetes journal Diabetologia, examined the extent to which sedentary time and moderate to vigorous physical activity were independently linked.

The researchers found it may be more effective to advise patients with known risk factors for type two diabetes to reduce their sedentary time, rather than focussing solely on physical exercise.