16 Aug 2018

Mitigating the health impacts of sitting for too long

From Afternoons, 1:28 pm on 16 August 2018

It's just a little effort that's required to curb the health hazards of sitting down for long periods of time, a University of Otago researcher says, but getting people to change their habits is tricky.

Many jobs - including radio broadcasting and producing, writing online articles under deadline, or producing academic papers - involve sitting at your desk for long uninterrupted periods of time.

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Photo: creative commons - pixabay

Studies have shown there are various negative health effects but National Heart Foundation Research Fellow Dr Meredith Peddie's latest analysis, out of University of Otago, shows it's pretty easy to counteract.

She tells Afternoons' Jesse Mulligan the long-term effects can be serious.

"Increased rates of cardiovascular disease and cancer, as well as diabetes and dying earlier than perhaps you should."

She says it seems to be caused by increasing concentrations of sugar in the bloodstream, "as well as the concentrations of insulin and fat in your bloodstream compared to when you get up and move during the day - even if you're not diabetic".

"What we think is going on is that when people sit for long periods, effectively the muscles in their lower extremities are ... turning off, and they're not doing what they should be doing in terms of pulling that sugar and fat out of the bloodstream."

Thankfully, that seems fairly easy to prevent.

"Getting up every half an hour and doing two minutes - between two and five minutes of activity would be really effective at reducing blood sugar levels.

"But we don't know if doing … five minutes every hour would be just as effective."

She says it doesn't have to be strenuous activity.

"As long as you're doing repeated muscle contraction for two minutes you're probably good.

"Get those muscles moving. Those leg muscles are big right, so they are probably more effective at pulling that sugar out of your bloodstream, but … you can do arm cranking and you'll get a similar result."

"You can just go and walk up and down the corridor."

She says the next step is to figure out how to get people to change their habits however, and actually take time out of their work day to move around a bit.

"I've got a little app on my computer that goes off every half an hour to remind me to do it and I have to admit that I don't do it every half an hour even though I know that it's good for me.

"The first think we're doing is getting people to come and talk to us in small groups about how they would perceive doing regular activity breaks at work and what they think would stop them from doing it.

"Using those people's ideas and comments we'll go on to develop hopefully an intervention that will be designed about getting people to change their behaviour long term so that we can look at the effects of this type of activity."

It's a task that's complicated by the fact people's lives are becoming more sedentary.

"You don't even have to go back that far to realise that our lives are getting increasingly sedentary, even here at the university we used to walk over to the library to pick up new journal articles to read and now of course we do it all, everything's available right from our computer.

"We don't actually have a really good idea of how much time New Zealanders spend sitting down although we're taking steps to address that issue, but we know in the states and in Australia they spend about 75 percent of their time sitting down.

"We have just done a little tiny study just of University of Otago employees and they are exactly the same, they spend 75 percent of the time sitting down."

It's also a tricky thing for people in certain jobs to take on.

"I'm lucky enough to have a standing desk so I can put my desk up and do a few squats and still be thinking about what I'm going to write when I've finished doing my squats, not really taking a break from the work.

"There are definitely situations where people are in employment where they probably can't do that."

Dr Peddie says those who can manage frequent activity breaks shouldn't expect to lose weight.

"We did a study last year where we looked at the effects of sedentary behaviour on weight and we founD that there was actually no real meaningful benefit.

"The benefit's more to your heart and your lungs and your vascular system."

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