Program: Is sitting the new smoking?

Tegan Taylor: So Norman, this is usually a time when I would ask you a question about your personal life, but I want to instead ask you a work-related question.

Norman Swan: Okay…

Tegan Taylor: I want to know how many times in the last decade you reckon you've done a story on sitting being the new smoking?

Norman Swan: Oh…

Tegan Taylor: Because it's a lot.

Norman Swan: Probably 10, yeah.

Tegan Taylor: No, it would have to be more than that.

Norman Swan: I've certainly talked about it more than that.

Tegan Taylor: I feel like we've talked about it at least 10 times in the couple of years that I've been on the Health Report.

Norman Swan: I did a television story on it at the Mayo Clinic of the guy who did a lot of the early research. 

Tegan Taylor: It's such an incredibly powerful tag line. Like, as someone with a marketing degree, I really can appreciate something that's very sticky in the mind. But today we're going to talk about whether it's a fair comparison or not.

Norman Swan: Indeed, because what you're listening to is What's That Rash? where we answer your health questions.

Tegan Taylor: And today's question comes from Jasmine, who has actually sent us her question in audio format. So, let's have a listen. 

Jasmine: Is sitting really the new smoking? And if so, what recommendations do you have for those of us with desk jobs?

Norman Swan: Good question.

Tegan Taylor: So first up, we know that smoking is really bad for us. Is sitting as bad for us?

Norman Swan: Well, let's go back a little bit, as we always do before we get to the crunch line, so we don't do the spoiler right up front; have you ever thought about what actually is sitting? 

Tegan Taylor: I know my butt is involved. 

Norman Swan: Well, you're sitting now, I'm sitting. But in terms of this discussion, sitting…you can call it sedentary behaviour, it's defined about really how much energy you're burning at that moment. 

Tegan Taylor: I do know that we like to go back to basics, but defining sitting is not where I expected this conversation to go. 

Norman Swan: Well, it helps when we come to the solutions. There are measurements of energy burn, which are called METs. And one MET is actually the energy burn that you've got at rest. If you walk reasonably fast, it's four METs, you're burning four times the amount of energy that you would just lying in bed at night.

Tegan Taylor: So it's not like a daily thing. It's sort of like for that minute if you were lying down you would have burnt X because you're working…

Norman Swan: Whatever the one means, but you'd have burned one. And if you are walking, you'd burn four. And if you're jogging, depending how fast it is, it's between six and 10. If you are sitting, it's 1.3.

Tegan Taylor: Okay, so if you are lying down in bed, is that one?

Norman Swan: That's about one, and sitting is 1.3. So the amount of energy you're burning, expending just by sitting is tiny over and above your resting metabolic rate. And you're supposed to burn about 500 METs a week. So if you do 1.3, you're a long way off. 

Tegan Taylor: Oh, now I'm trying to do maths. How many more METs is…if I just lay in bed for a week, what more am I meant to be doing than that?

Norman Swan: Well, you're supposed to be doing 500 METs more than that. 

Tegan Taylor: Oh, 499…

Norman Swan: Yeah, that's right, because everybody is doing the maths now, and seen, well, that's okay, I can knock out my 500 METs just by sleeping all day. 

Tegan Taylor: If I know the What's That Rash? audience, I know that they've got their calculators out already. 

Norman Swan: I know, and they're going to contradict us. So the bottom line here is that if you are sitting, you're not burning that much more than if you were just having a sleep and your resting metabolic rate, and you've got to burn 500 times more than that. So it's a long way to go. 

Tegan Taylor: So we're kind of talking about two different things here, because we're talking about energy expenditure from sitting versus smoking, which really isn't about energy expenditure. It's about different health harms. So what's the harm of not moving?

Norman Swan: Well, if you compare people who are most sedentary to people who are least sedentary, their chances of dying at any age is about 22% higher than active people.

Tegan Taylor: Which could be because the reason that they're sedentary is because they have health conditions that force them to not be able to move as much.

Norman Swan: That's a figure that's corrected for the reasons that you might be sitting and your level of health or illness, so corrected for level of health and illness and for everything else you might know about, and you just isolate sitting, sedentary behaviour versus active behaviour, then the increased chance of dying at any age is about 22%. 

If you are a current smoker versus a never smoker, it's 280% higher, your chances of dying at any age. And if you're a heavy smoker, it's over 400% higher. Put another way, those who sit most compared to those who sit least have an excess chance of dying of 190 deaths per 100,000 people. And if you're a heavy smoker, it's 2,000 excess deaths per 100,000 people. So that just gives you the dimensions. So sitting is nowhere near the new smoking. It's not great for you, but it's nowhere near.

Tegan Taylor: Yeah, I think this is the thing, I wonder if…I first heard about this sitting versus smoking thing about 10 years ago, probably around 2012, 2013 and I wonder if…because if you look back through the last 50, 70 years, smoking rates have declined dramatically, and a lot of people have gained a lot of healthy years because they're not smoking anymore. They're smoking less, less than they used to be, but we are more sedentary than we used to be. And I wonder if, in public health terms, it was this sense of seeing one line go up in terms of sedentary behaviour and the health that we're losing there while another one was going down, and needing to sort of shift our focus to a different problem.

Norman Swan: Well, that's true, but the reality is that we haven't traded it off one for one. I mean, the great thing about sitting versus smoking is sitting is not addictive.

Tegan Taylor: I mean, depends how much Netflix you watch.

Norman Swan: That's probably true. That's right, so what you do when you're sitting actually makes a bit of a difference. We can come back to that if you want. I mean, another way of looking at this is what proportion of the world's deaths are due to sitting versus smoking. So they reckon that between 4% and 6% of the world's deaths can be attributed to sedentary behaviour, and it's 21% globally for smoking. 

Tegan Taylor: The fact that we can even put a number on it for sedentary behaviour is actually really interesting. 

Norman Swan: It is, and it does help put things into perspective. It's not that physical activity is not important, it is important. So if you removed smoking from the equation, as we are doing at the moment in Australia, with very, very low rates, and in other countries as well, then the effect of physical activity grows, because then you've got your residual risk factors, which is nutrition, overweight, exercise, the air that we breathe and so on. The air that we breathe is actually quite important here because fine particulate air pollution is the equivalent of smoking. You're breathing in these fine particles that are irritating your lungs, getting into your bloodstream, causing inflammation.

Tegan Taylor: One of these days we need to have a proper chat about fine particulate air pollution, because I feel like it comes up almost as much as the Mediterranean diet, and I feel like I need a new trumpet or something to blow when you mention fine particulate air pollution.

Norman Swan: Yeah, I think trumpeting air pollution is a good idea.

Tegan Taylor: I will rustle something up for next time you mention it, for sure. So coming to sitting, then you said that 4% of the world's deaths could be attributed to sedentary behaviour.

Norman Swan: That's the lower end, yeah.

Tegan Taylor: I'm just loving that we can put a number around that. What actually is…like, someone's chair hasn't killed them, right? Like, what's actually causing the deaths in those situations?

Norman Swan: It's probably coming back to that resting metabolic rate. It's more probably that you're not getting the benefits of physical activity. So physical activity gives you extra benefits, which you lose, miss out on, if you're sitting. But I'll come back to what I said earlier, which is it sometimes depends on what you're doing when you're sitting. So for example, if you're sitting in the office for eight hours a day, the evidence suggests that's less toxic than if you're sitting watching your current addiction, which is Netflix…

Tegan Taylor: Don't take that away from me.

Norman Swan: Or ABC iView, because what you are potentially watching when you're watching streaming services, you're also watching ads, those ads can have unhealthy food attached to it, and also you might eat unconsciously while you're doing that and put on extra weight because you're actually consuming more calories because you sit and eat on the couch. 

Tegan Taylor: But I sit at my desk and eat all day, so…

Norman Swan: Yeah, I don't like messing up my keyboard, so I don't tend to do that. But, you know, so what you do all day actually makes a difference. And I'll come back to that when it comes to the solutions, because what you've got to do to counteract office sitting or computer work is actually less than counteracting watching telly. 

Tegan Taylor: I would like to put some numbers around how much we're actually sitting, because I think we intuitively know that we're sitting a lot more than we used to. Our jobs on the whole, en masse globally, are less physically energy intensive as they used to be, with some pretty big exceptions. Do we have good numbers around how much Australians are sitting each day? 

Norman Swan: We don't have great numbers around that, but we do know that the vast majority of adolescents aged 15 to 17 are not meeting the physical activity component of the guidelines, which means that if you are supposed to be getting 150 minutes a week of moderate exercise or burning 500 METs, they're not reaching that, which means that they are sitting or lying down too much. What else could you be doing if you're not meeting those guidelines? About 40% of adults aged 18 to 64 don't meet the physical guidelines. And a disturbing nearly 60% of adults age 65 and over didn't meet the physical activity guidelines when in fact that's probably the age where they'd benefit most.

Tegan Taylor: And I suppose it's worth calling out in this spot that getting out of a chair sometimes isn't possible for people, but there still are ways to be physically active, even if that's your situation. 

Norman Swan: Yes, and the best sitting data comes from the United States, but I'm not sure we can compare Australians to Americans, or we don't like to anyway. And so in the United States' context, sitting time increased by about 20 minutes a day in the 10-year period up to 2017, 2018.

Tegan Taylor: And then what happened? Oh, we don't know have data after that.

Norman Swan: The statisticians have been sitting on their hands.

Tegan Taylor: Sitting, yeah, exactly. So in terms of offsetting the sitting part, my watch tells me to stand up for at least one minute of every hour. Is that enough to offset the fact that I'm sitting for the other 59 minutes?

Norman Swan: Companies have spent a fortune on standing desks so people can stand instead of sit. The evidence is that standing still is probably not that much different from sitting still. Because what'd I just say? It was 1.3 METs, or something like that, for sitting. Well, if you're standing, does it go to 1.4, 1.5? It doesn't go up that much. If you're moving around, that's different. So if you get up and you walk, if you use the stairs to go down for your coffee and come back with your coffee and spill it coming back up the stairs, that makes a difference. So incidental exercise makes a huge difference during the day, but just standing up is probably good for easing your muscles and getting rid of stiffness, but it doesn't make much difference in terms of the core thing that we're talking about, which is how much extra energy you're burning through physical activity in a week.

Tegan Taylor: So Jasmine's question was asking for specific advice for people with desk jobs. Well, I guess we've already covered off the first part of her question, which is that, no, sitting isn't the new smoking, but that's not to say that it's not a problem and one that we can't intervene with. What are some practical solutions for people with desk jobs? 

Norman Swan: Well, if we take the big picture, if you're sitting, say, eight hours a day, which most people aren't for the full eight hours a day, but let's say you're sitting eight hours a day in an office job, you're getting up a bit and moving around and what have you. Then 45 minutes of moderate exercise most days of the week, in other words, the physical activity guidelines, in terms of the health benefits that you get from that completely counteract the health decrement or health problems that you might get from sitting that amount of time a day. 

Tegan Taylor: So we've quantified that, basically what the amount is that you have to do to make up for the fact that you're sitting for the rest of the time. 

Norman Swan: And it's hard for women with kids, they find it really hard to put in this amount of exercise, particularly if you're a single parent. But if you're co-parenting and you work it out with your partner and you're getting those 150 minutes a week, then you don't need to worry too much about that sitting time. If the sitting time is…you're a retiree, and you've painted the house and done the garden, and you're bored with your retirement and you're watching television streaming all day, then in fact people think you've got to do more exercise in the 150 minutes to counteract it because of what I said earlier, is that there are certain unhealthy things that happen when you're sitting, it's unconscious eating, putting on more weight than you need to in that sense, unhealthy eating because you're watching the ads. It's not good for kids sitting watching television, it's associated with obesity and overweight in children. 

Now, if you can't do a solid 45 minutes, then incidental exercise, particularly exercise that gets your heart rate up, does count. So you can add up your incidental exercise during the day. This is where the step counter comes in. It's probably the most useful thing about step counters is it makes you record your incidental exercise. So if you're in a place with stairs, taking the stairs rather than the lift, leaving the car at home, getting public transport, you've got to walk to public transport, and if you're lucky enough to live in a city that's cyclable, cycling to work and back, which is what I've actually started to do. And I'm amazed, just cycling to work a couple of days a week gives me my 500 METs.

Tegan Taylor: Are you recording METs? Is that how you figure it out? 

Norman Swan: Well, I do tend to figure it out in terms of how much more I'm burning than resting metabolic rate. I often say that I exercise to eat. 

Tegan Taylor: I can think of a thousand other reasons to exercise though, beyond the calories in or the calories out. It makes you feel so good, and also you want to have that muscle tone for when you get older, so that you can keep doing it as you age as well. 

Norman Swan: And the more muscle that you've got, the more active metabolic tissue you've got, which means you've got lower risk of coronary heart disease, lower rates of high blood pressure, et cetera. Yeah, you're right. I was being facetious. We do get a lot of extra benefits from it. But it's interesting that if you do leave the car and get that extra exercise, how it does add up, particularly aerobic exercise. You've got to put a bit of effort into muscle strengthening. 

Tegan Taylor: So coming back to desk jobs, basically, what's the bottom line for Jasmine and all of us who work in office jobs, or just spend a lot of our time sitting down? 

Norman Swan: Well, I think in terms of the way we do our jobs these days, it's inevitable. And what I would argue is; don't get anxious about it, it's not the new smoking. If it was the new smoking, then we could panic about it. As long as you're doing something about it, which is being mindful about your exercise, and that's where a wearable can help you, and most people with a smartphone actually have a counter on their phone, so you don't need to wear something on your hand. And it's not hugely accurate, but it's accurate enough, where you can record your incidental exercise and keep that up. That's probably one of those handy uses of it when you've got a sedentary job, is how much activity you're getting at other times. And if you've got kids who are young, and you throw them in the pram and walk up to the shops, that's going to be a few METs. 

Tegan Taylor: So, sitting is not the new smoking. Do take it seriously, but getting out and just meeting those physical activity guidelines is probably enough to offset the harms of the rest of the sitting you're doing.

Norman Swan: Yep, and whip your partner into shape so you've got time to do it. And just before we wind up here, I just want to add something here, that recently the Australian government came out with its statistics on what it spends on health problems. Cancer and heart disease are the two top spending health conditions in Australia, and musculoskeletal problems are number three. So that's arthritis, that's injuries, falls, broken bones, things like that. So the top three conditions that we spend money on in Australia are partly preventable by exercise and certainly not smoking. If you look at the burden of health issues, so in other words this isn't the financial burden but the burden on us in terms of disability, shortened life, it's still cancer number one, heart disease number two, and mental health problems and substance use problems number three, and again, more physical activity helps all three. So help your fellow taxpayer and help yourself. 

Tegan Taylor: Or maybe the government could spend some money on making those things better, more accessible and safer for people, so that they're saving money in the long run as well. Like, yes, absolutely, as an individual, get out there, but also, make it easier. 

Norman Swan: Yeah, and don't complain about local governments that put in cycle tracks and make your drive to work slower.

Tegan Taylor: Says the newly minted cyclist…

Norman Swan: That's right, I've got a conflict of interest. 

Tegan Taylor: You've suddenly become radicalised. Well, thank you so much to Jasmine for sending in that question. And thank you to everyone who sends in questions. You can send yours in to thatrash@abc.net.au, which is also where you can send us your feedback. 

Norman Swan: And this week we've got feedback on What's That Rash? on mobile phones and do they cause cancer. And it sounds as though we got our physics slightly wrong. 

Tegan Taylor: This is on me. I should have checked the electromagnetic radiation spectrum. Things that I never thought I'd have to do for a health show. James and Derek have both written in to say, Tegan, get your facts straight. The microwave part of the spectrum lives with radio waves, not with ultraviolet on the other side of the visible light spectrum. My big apologies. It's been a while since I've studied physics, but I have attention to detail in every other part of this show. And then James also wanted to say that we talked about green potatoes. 

Norman Swan: Yeah, that was me, so that's on me now. So I was saying how I peel potatoes because disturbingly I find the green underneath as a sign of where the toxins are, but what James says is:

Tegan Taylor: James says that the toxins aren't green, that's the chlorophyll. But that is where the toxicity lies in the potato, so I feel like James is splitting hairs here.

Norman Swan: That's right. Just get rid of it. Don't worry about it. Do you really want a green roasted potato? I don't think so.

Tegan Taylor: Come at us with your corrections to our feedback or any other part of What's That Rash? by emailing us, we are thatrash@abc.net.au.

Norman Swan: And we'll see you next time.

Tegan Taylor: See you then.