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Not everyone can get to the gym - but is it really possible to get fit by just doing one's chores, asks Michael Mosley.

You might want to read this article while standing up. Or perhaps while strolling around the room. Because the sad fact is that most of us spend far too much time sitting on our bottoms staring at screens.

We drive everywhere, avoid the stairs, pack our houses with labour-saving devices and email colleagues rather than walk down the corridor to talk to them. We are a slothful lot and the most common reason given for not doing enough exercise is lack of time.

But what is enough exercise? Most health experts recommend at least 150 minutes of moderate-intensity physical activity, or 75 minutes of vigorous activity a week. Any activity will help but it has to be moderate, vigorous or high intensity if you really want to reduce the risk of heart disease, cancer and obesity.

If you're not that keen on going to the gym or playing sport (and surveys suggest less than 20% of us are), then can you cheat your way to 150 minutes of moderate-intensity physical activity by doing regular weekly chores? And if so, which ones count?

Find out more You can watch Trust Me, I'm a Doctor, with Michael Mosley and others, on iPlayer

To find out, the Trust Me I'm a Doctor team recruited eight volunteers, all different shapes and sizes, and fitted them with activity monitors. Then we asked them to do a range of indoor and outdoor tasks.

We started with four typical household chores - ironing, vacuuming, dusting and mopping.

After our volunteers had completed each activity, exercise scientist Dr Andy Blannin collected their data and graded each on a scale of one to 10, using something called a MET score.

MET (Metabolic Equivalent of Task) is a measure of energy consumed per hour. A MET score of one is the sort of energy you would expend watching TV.

Anything which gets a score above three counts as moderate activity. Above six and you are in the realms of "vigorous".

Image copyright Thinkstock Image caption One hour watching TV = one MET

Ironing and dusting, not surprisingly, scored modestly, with MET scores of 1.3 and 1.5 respectively.

Vacuuming and mopping, though hardly Olympic sports, scored just above three METs, making them moderate-intensity. While doing these activities our volunteers were burning three times more energy than when they were just sitting.

Healthy living in the Magazine

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Five exercises for the 30% who never exercise (13 March)

How much better is standing up than sitting? (October 2013)

Can walking while working make you live longer? (January 2013)

Our volunteers claimed to spend an average of 37 minutes per week on these two tasks, which meant they were already almost a quarter of the way toward the 150-minute target.

Then we moved outside, to see how much energy they would burn through doing typical outdoor chores like washing the car, cleaning windows, mowing the lawn or planting flowers.

Surprisingly enough all these activities broke the magic MET barrier of three. Washing windows required the least effort (3.1), then planting flowers (3.4), washing the car (3.6) and finally mowing the lawn, which racked up a score of 4.4.

As Andy pointed out, although planting flowers doesn't require a lot of moving around, it does involve using a bit of upper body strength, sufficient to count.

Our volunteers said they spent an average of 72 minutes a week doing outdoor activities. So when we combined indoor and outdoor chores their total reached an impressive 109 minutes.

More MET values

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The Compendium of Physical Activities - first developed by Dr Bill Haskell of Stanford University - gives MET values to a wide range of activities. Among them:

Pulling a rickshaw - 6.3

Playing the accordion - 1.8

Serving food at Church - 2.5

Tanning hides - 4.0

Throw in six minutes a day of brisk walking (MET score of 3-4, depending on how briskly you walk) and you can hit the 150 minutes a week without donning the lycra.

Image copyright Getty Images If you prefer to do something more enjoyable than cleaning the loo, then dancing clocks up an impressive 7.8 METs

If you prefer activities that are more intense, there is a range of things that, according to the Compendium of Physical Activities, you can do around the garden.

Vigorous activity means anything that rates over six METs, and to achieve that you would need to be either "chopping wood and splitting logs" (6.3), "digging, spading, composting" (7.8), or "shovelling snow, by hand" (6.0).

According to the same source, the only domestic activity that falls into the vigorous range is "scrubbing floors and bathtub" (6.5), though "moving heavy furniture" (5.8) comes close.

If you prefer to fill your activity quotient by doing something more enjoyable than cleaning the loo, then dancing - "disco, folk, Irish, line dancing or country" - clocks up an impressive 7.8 METs. Unfortunately sexual activity ("vigorous effort") doesn't count as it comes in at a disappointing 2.8.

Whatever you decide to do, it is better to sprinkle your activity across the week rather than trying to get it all over and done with in one go. "We know that some of the health benefits of exercise are quite transient and may only last 12-24 hours," says Andy. "So it would be better to be doing a bit of activity every day rather than condensing it all into a couple of days."

And if you were wondering, one of the best all-round activities seems to be gardening.

Trust Me I'm A Doctor continues on BBC Two at 21:00 GMT, 29 October, or catch up on iPlayer

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