Illustration: Kerrie Leishman
Forgive me for saying so, but don't you think you'd be better off going for a run - or even a brisk walk - than reaching for another mince pie? (The ones my wife made this year were irresistible.)
Chances are you don't think it. Or maybe you think it, but you don't intend to act on it. If you can't take a day off on Boxing Day, when can you?
I hate to say it, but humans have a slothful streak. We want to live comfortable, enjoyable lives and we assume the less physical effort this involves the better. But one of the most unremarked and remarkable discoveries of our times is that it doesn't work like that.
As a writer about economics, I suppose I'm required to be an advocate of progress. But I'm learning progress can be a tricky beast. Sometimes it involves moving away from the practices of the past as far and as quickly as possible. But occasionally we discover we need to retrace our steps.
A major element of humankind's progress - of our civilisation - has been our unrelenting efforts to take the effort out of all we're required to do to live our lives. That story begins with our discovery of first stone, then metal tools. It progresses to our discovery that settling in one spot and farming crops and animals was a lot safer, more comfortable and prosperity-inducing than hunting and gathering.
Fast forward to the industrial revolution, which began in the second half of the 18th century. It, too, was fundamentally about taking the physical effort out of work, first with the discovery of steam power, then later, electricity and the internal combustion engine - all of them powered by the burning of fossil fuels.
Along the way we invented a multitude of ways to mechanise work - from the spinning jenny to the typewriter - thereby greatly reducing the number of workers needed to produce a given quantity of goods and services or, looking at it another way, allowing a given number of workers to produce a much greater quantity of goods and services.
Whichever way you look at it, our unceasing search for new and better ''labour-saving'' devices has greatly increased the productivity of our labour - the quantity of goods and services the average worker is able to produce in an hour - and this explains why our material standard of living is many times higher than it was at the time of white settlement in Australia.
Usually, this is what economists portray as the object of this grand exercise, making ourselves richer. But it's equally true that a central element of the exercise has involved taking the physical exertion out of work. We haven't ended up doing a lot less work than we used to, but our work has become much less physical and much more mental, requiring us to be a lot better educated and trained.
More recently - and particularly with the advent of the information revolution - we've moved from taking the physical effort out of work to also taking it out of leisure. We drive when we could walk or ride around our suburbs at the weekend. For home entertainment we no longer sing or recite to each other, but turn on some electronic device. And the commercialisation of sport means not only that we watch professionals rather than playing ourselves, but needn't even leave the house to watch a game.
This is where we've overreached, however. This is where nature is striking back. Combine the way machine-produced food has never been more enticing, more plentiful or as cheap with the success of our efforts to strip physical exertion from work and leisure, and you get an obesity epidemic.
And it's not just that. As each year passes the medicos uncover ever more evidence of the many ways our lack of exercise is contributing to our ill-health, including heart disease, type II diabetes, high blood pressure, cancer, depression and anxiety, arthritis and osteoporosis.
To put it more positively, and to borrow a slogan from the American College of Sports Medicine, exercise is medicine. This is what I find so remarkable, so surprising.
Recent research by medicos in Texas has found that previously sedentary women who began moderate aerobic exercise a third of the way into their pregnancy had significantly fewer caesarean deliveries and recovered faster after the birth.
Research by Dick Telford and colleagues at the Australian National University has found that primary school children who are more physically active and leaner get better academic results and, even more so, that primary schools with fitter children achieve better literacy and numeracy.
Research quoted on the Exercise is Medicine website says active people in their 80s have a lower risk of death than inactive people in their 60s.
Regular physical activity can reduce the risk of recurrent breast cancer by about half, lower the risk of colon cancer by more than 60 per cent, reduce the risk of Alzheimer's, heart disease and high blood pressure by about 40 per cent and lower the risk of stroke by 27 per cent. It can decrease depression as effectively as Prozac or behavioural therapy.
According to the site, a low level of fitness is a bigger risk factor for mortality than mild-to-moderate obesity. And regular physical activity has been shown to lead to higher university entrance scores.
But here's the bit I like best (and know from experience is true): research shows that exercise makes you feel better, reducing stress, helping you sleep better and feel more energetic. The unexpected truth is that it's exertion, not the avoidance of it, which makes you happy.