做家務就能健身，你還在騙自己嗎？

邁克爾·莫斯利說過，不是所有人都有機會去健身房，但就算做家務也能健身。這是真的嗎？

研究團隊找來八個形體各異的志願者，接着讓他們完成一系列戶內和戶外任務，包括熨燙、吸塵、打掃以及拖地。

志願者們每完成一項活動，運動科學家就會根據MET（任務代謝當量）指標從1到10給他們打分。能獲得3分以上，纔算是中等強度的活動。六分以上，算是“劇烈”活動。

熨燙和打掃的MET得分分別是1.3和1.5，這並不讓人覺得吃驚。吸塵和拖地這兩項幾乎能與奧運會匹敵的活動，但MET得分也僅爲三分，它們屬於中等強烈的運動。

接着他們又對戶外運動進行測試，測試表明，清潔窗戶得分最少（3.1），其次是種植花草（3.4），清洗車輛（3.6），分數最高的是修剪草坪，獲得了4.4分。

唯一達到劇烈活動指標的室內家務是“擦地板和浴缸”（6.5）。所有家務活中效果最好的是園藝活動。

如果你更喜歡做些有趣的活動，而非打掃廁所這種類型，那麼跳舞吧。迪斯科、民舞、愛爾蘭舞這些舞蹈的MET得分高達7.8。不幸的是，性生活（“程度激烈”）並不包括在內，因爲它只有2.8分。

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? 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".

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.

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.

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.

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.