It is a good idea – and not just because it is practical for squeezing in exercise before or after work. Clothes you can move in make it easier to follow all that advice to take the stairs not the lift, get off the bus a stop earlier and take a brisk lunchtime walk.

Hallett’s idea got a mixed reception. Some people liked it, others did not, with one commentator arguing that workplace dress codes promote discipline and productivity, and that wearing more relaxed clothes could undermine this.

Whether we’ll win the right to wear yoga pants to work is anyone’s guess but either way we have to get serious about breaking up the long bouts of uninterrupted sitting that are linked to a higher risk of chronic disease.

Although sitting is often called the new smoking, it is probably harder to tackle in the workplace than tobacco itself. It is one thing to ban smoking at work, but reducing sitting in the office is less straightforward.

''It’s a bit like alcohol. While there’s no safe level of smoking, there are safe levels of sitting and alcohol,'' says Marcus Dripps, President of the Australian Physiotherapy Association and a specialist in occupational health.

Some companies are making a difference with height-adjustable desks, but if you do not have that option you need other ways to break up sitting, he says. It is a question of looking at your own work environment and deciding what is practical. How much flexibility do you have for moving things such as printers, waste bins or even phones away from your desks to help force you out of your chair? Can you stand up and move around when you make phone calls?

''In some workplaces standing up to talk on the phone can be a distraction for other people, but if you have a hands free phone you can find a place to make calls that won’t disturb others,'' he says. ''You might also be able to break up sitting by shifting your laptop to a filing cabinet or other higher surface so you can do some tasks standing up. Walking meetings and standing meetings are other ways – some workplaces are now designed with meeting rooms that allow people more space to stand.''

Compared to sitting, standing is also kinder to the back – another reason why standing up to use a keyboard some of the time is helpful, says Sydney exercise physiologist Hamish Fibbins who works with companies to help improve employee health.

Besides burning more kilojoules and activating the muscles in your glutes and legs, standing keeps your spine in neutral. Sitting, on the other hand, encourages slouching, which puts pressure on your lower back, he says.

Standing rather than sitting on public transport also cuts sitting time. ''If you have an hour’s commute to and from work by train or bus, that’s two hours in the day that you’re not sitting,'' Fibbins says.

At work he recommends setting a timer every hour as a reminder to stand up and suggests using these breaks for tasks such as making phone calls or collecting documents from the printer.

''It’s also crucial to get away from your desk for a walk at lunchtime – if you don’t have long, just 15 minutes or a walk around the block will help,'' says Emily Burgess, a Canberra accredited practising dietitian and exercise physiologist who helps companies create healthy workplaces.

Burgess believes Workout Wear Friday has potential – especially if people in senior positions lead the way.

''Workout clothes do make you feel more like moving,'' she says. ''And workplace cultures can change – smoking at work used to be normal, but now no one would dream of lighting up in the office.''

What we eat between nine and five matters too – especially if the office culture embraces cake, she adds.

''It just takes one brave person to make a stand by bringing in healthy food to share like nuts and fruit for morning tea. If there’s a birthday, bring in a healthier cake that you’ve made yourself.

''Fund-raiser chocolate is another problem – again there’s pressure to buy it and if it’s 3pm and you’re hungry it’s very tempting. But there are healthier ways of fund-raising, like selling small pots of herbs.''

What does your workplace do to make the working day healthier?