Why Australia doubled its exercise guidelines?

Australians are sitting down and lying around so much, experts have doubled the recommended amount of exercise and say we need to get up out of our chairs – even if we already do “enough” exercise.

More and more studies are finding links between “sedentary behaviour” and weight gain, type 2 diabetes, poor muscle tone, heart disease and dying earlier. The new guidelines are the first to explicitly address our love of lounging and our habit of sitting at work.

The latest advice is to ‘mix and match’ a range of activities, and to think of exercise as simple habits that can be built into your day.

Sit

What are the new guidelines?

The Government’s new guidelines are called the Physical Activity and Sedentary Behaviour Guidelines.

Doing any physical activity is better than doing none. If you currently do no physical activity, start by doing some, and gradually build up to the recommended amount.

Accumulate 150 to 300 minutes of moderate intensity physical activity or 75 to 150 minutes of vigorous intensity physical activity, or an equivalent combination of both moderate and vigorous activities, each week.

Be active on most, preferably all, days every week.

Do muscle strengthening activities on at least two days each week.

Minimise the amount of time spent in prolonged sitting. Break up long periods of sitting as often as possible.

What is ‘sedentary behaviour’?

Being ‘sedentary’ means sitting or lying down for long periods (not including sleeping). So, a person can do enough physical activity to meet the guidelines and still be considered sedentary if they spend a large amount of their day sitting or lying down at work, at home, for study, for travel or during their leisure time.

ABC Health and Wellbeing’s Claudine Ryan explains:

Experts say we’re sedentary on average for seven to 10 hours a day (and this doesn’t include our time spent sleeping). Even if you are meeting, or exceeding, the recommended 60 minutes a day of moderate intensity physical activity, you can still be considered sedentary. (This group of people is sometimes referred to as ‘active couch potatoes’.)

While researchers are still trying to understand exactly why sedentary behaviour has such a negative effect on our health, it appears to be related to how our bodies process fats and sugars. There are enzymes involved in this process that are released when certain muscles contract during standing. When you sit for prolonged periods the production and activity of these enzymes appears to slow down.

Q&A: putting the guidelines into practice

Professor Wendy Brown from the University of Queensland’s School of Human Movement Studies was lead author on the report that led to the new guidelines. We asked her a few questions about the reasons for the new recommendations, and how she sticks to them in her own life.

Why have you included ‘sedentary behaviour’ (sitting or lying down, except for sleeping) in the new guidelines?

Two main reasons: 1. There is growing evidence that too much sitting is bad for health. Specifically, when muscles are not moving, metabolites – especially fats – are not cleared from the bloodstream as quickly. High circulating levels of triglycerides – fats – eventually lead to metabolic illnesses like diabetes and cardiovascular disease. The latest evidence is that the effects worsen when daily sitting time is more than seven hours. 2. We figure that if people sit less, then unless they just stand still (unlikely) they will be moving, which is good for them! My personal view is: it is all about moving more.

If more than half of Australian adults are already not meeting the old guidelines, why have you recommended people do even more exercise than before?

Our latest data say that more than half of young adults meet the old guidelines and about half of mid-age people do. But on average Australians are gaining weight at the rate of about 500 grams per year, so we all need to move more. Increasing weight leads to diabetes, cardiovascular disease, some cancers, arthritis, back pain, the list goes on. And of the half who do meet the old guidelines, half of them do enough to meet the new ones. So if one quarter of the population can do this – it is not a big ask?

What sorts of things do you do when you’re at work, to avoid sitting for too long?

I have a standing desk and try to stand most of the day. I walk across the campus to get coffee and/or lunch. Sometimes I do walking meetings – it is a nice campus – but at the moment it is too hot. I have a bottle of water and I drink it as it makes me take a break to go to the loo. I go 30 metres to the printer! A friend of mine stands up to answer the phone and stands up every time someone walks in. I am already standing so I can’t do that; in fact I often sit down when students come in to discuss something.

Can we compensate for a lot of sitting by doing a lot of exercise outside work hours?

The jury is out on this one. Some would say sitting is an independent risk factor – something that raises the risk of disease by itself, without other factors coming into play – but this view is being questioned. My take on it is that if you sit for 10 hours a day, then doing 30 minutes of walking won’t help much in terms of ‘cleaning out’ the blood vessels, but maybe if you went to a vigorous aerobics class for an hour then the compensation idea takes shape. Look at athletes who train hard for two hours each morning then lie about all day – they are fit and healthy. So yes, it is my view that you can compensate but the ‘experiments’ have not been done to answer that precisely yet. Data from cohort studies – like our Australian Longitudinal Study on Women’s Health – are certainly showing combined effect of sitting and inactivity are very bad.

Is it better to do big bursts of exercise, or to spread it out over the week?

Tricky question – I told you this was complicated. We are proposing that exercise is like medicine, but nice medicine! So we need to take a dose every day. Getting back to those lipids – if you ‘clean them out’ every day they won’t have chance to be deposited on the walls of the blood vessels. Having said that, a big burst of vigorous exercise might work like a hose and clean things up? Seriously, evidence shows that ‘weekend warriors’ – those who only exercise on the weekend – do reap benefits, but there are very few studies. So yes – weekend golf for five hours (that’s your 300 minutes!) is great, but a little every day would be even better. Hence the second guideline: try to do something every day.

How do you personally make sure you meet the exercise guidelines?

I bike to and from work – it is 15 minutes each way – so that gets to the lower end of the range (30 mins) on weekdays. Some days I ride to work the long way round – that is 45 mins, then 15 mins back or vice versa. So that’s the hour. I try to do that twice a week. If it is raining I walk instead – it takes 35 minutes each way. So I get my ‘base’ activity through transport to work. To be honest that is all I do some weeks when I am really busy at work (always!?) But I do try to do a longer ride at the weekend – maybe two hours, but I am very slow, and I try to fit in dancing classes whenever I can – maybe one evening or a weekend class each week.

In what ways does having more muscle benefit our bodies?

More muscle means all those metabolites – products of metabolism, for example fats – are taken up and used. The more we work, the bigger the muscles, the better we remove metabolites from the blood vessels. There are receptors on the muscle walls that are very important for regulating blood sugar and therefore preventing diabetes. No muscles equals no receptors equals increases in insulin and related endocrine problems.

Not everyone can get to the gym twice a week for a weights session. What sorts of things do you do for muscle strengthening?

I go to pilates and yoga classes as often as I can – maybe once, sometimes twice a week. And if I can’t get there I try to do strengthening exercises at home while I am watching TV: sit-ups, that sort of thing. Last weekend I clipped the hedge with hand shears, not an electric cutter. It is quite big so I think my arms had a bit of a workout. Gardening is a very under-rated form of exercise – especially if you are digging and pushing a barrow of soil or mulch.

Is it ok to be overweight if you’re fit or should you try get your weight down as well?

Being overweight (ie BMI 25-30) is fine if you are fit, but being obese (BMI 30+) is never healthy.

If you are overweight I would say focus on being fit and don’t worry about weight.

We hear that weight loss is mostly about diet, not exercise. Why should people focus so much on moving?

Because moving uses energy, not only during the exercise but afterwards as well. If people use dieting to lose weight they are more likely to maintain the weight loss if they increase their exercise levels as well. The new guidelines are not about weight loss but the evidence suggests you should do an hour a day of exercise to lose weight. Obviously, the more you want to lose the more you must move and the less you must eat.

Have you ever had a time when you couldn’t do exercise, and if so how did you get back into it?

I travel a lot for work and often there are periods when I can’t ride my bike, so I try to walk as much as I can, wherever I can. Last year I was clocking more than 20,000 pedometer steps a day on a work trip by walking everywhere. It is difficult to move much on long-haul flights but many airports around the world have opportunities to walk miles between connecting flights, especially if you walk instead of taking the little train – if it is allowed, as it is Hong Kong for example.

Following illness or injury I mostly try to walk or swim to get back into things.

By Cristen Tilley; Illustrations by Lucy Fahey

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