Calories in the Garden
There is no doubt that gardening, like walking and swimming is a good form of general exercise. Like swimming and walking, gardening does not make too many demands on the joints (apart from straightening up of course) and importantly it can be taken at ones own pace. And of course apart from the physical health side of the equation there is the pleasure and relaxation of the mind aspect for the gardener. Well nearly always, the Zen of weeding does not seem to extend to weeding out knot-weed and so on!
We all have some lingering concern about the link between exercise and weight. When we have a good day in the garden exactly how many calories do we burn off? And of course there is the following question, how many calories are put back by having a chocolate biscuit with that well earned cup of tea?
The basic calorific requirement is calculated from assumptions about the needs of average men and average women, and naturally average levels of activity These are usually given as about 2 200 Kcal per day for women and 2 500 Kcal for men. Slightly higher for men because they are in general larger, but also because even at the same weight a man looses heat faster than a woman. And before we get to the gardening and the calculations a reminder that when people talk generally about calories they mean Kcal, that is Kilocalories or thousand calories. The actual calory is a very small unit.
Where do the numbers come from? The first item is the basal metabolic load, that is essentially the calories you burn up when asleep, and the starting point for adding up the other demands when you are awake. Table 1 shows the calory requirement per minute for some activities.
|Basal metabolic load||1.0 Kcal per min|
|Sitting around||add||0.3 Kcal per min|
|Standing||add||0.6 Kcal per min|
|Casual walking||add||1.5 Kcal per min|
|Intermediate activity||add||2.0 Kcal per min|
So for a day made up as follows we get the guideline figures, or thereabouts, table 2.
|Basal metabolic load for the day||1 500 Kcal|
|8 hrs sleeping||add||0 Kcal|
|6 hrs sitting||add||108 Kcal|
|3 hrs standing||add||108 Kcal|
|4 hrs casual walking around||add||360 Kcal|
|3 hrs other activity||add||360 Kcal|
So lets look at our gardening activities to replace other activity above.
A bit of general planting out will consume an additional 260 to 300 Kcal per hour, weeding clocks in at about 300 Kcal per hour, manual pruning comes in at the same. Clearing land is understandably more demanding at 350-400 Kcal per hour, and anyone who goes in for double digging (frowned on by many) will consume an addition 650 Kcal per hour over the basal load. What about mowing the grass, manual that is, this takes about 400 Kcal per hour, raking up afterwards about 260 Kcal per hour. Perhaps we can finish with a gentle bit of hose-pipe watering, about 50 Kcal per hour.
So lets look at 3 hours of gardening. For example; planting out 1 hr (300 Kcal), plus weeding 1 hr (300 Kcal), plus half an hour of pruning (150 Kcal), plus half an hour of watering (25 Kcal); total calories 775 Kcal. If we have replaced 3 hours of sitting reading by gardening we have an additional 721 Kcal consumed by the morning with our boots on. If on the other hand we replaced 3 hours of casual walking by our horticultural activity we end up consuming only an additional 415 Kcal.
So when we come in for a cup of tea what is all of this equivalent to? Our replacement of sitting reading by gardening translates into 5 slices of Madeira cake, or 6 Chocolate club biscuits, or even three and a half pints of ale. Even the more modest change from walking to gardening translates into for example 5 chocolate digestives, or 6 hob nobs, 5 glasses of dry white wine (if you are working on a late Summer day!), or an amazing 10 to 11 dry sherries. So leave it to a cuppa with one biscuit or slice of cake and you are winning all the way!
First published in the Shropshire Group Newsletter, January 2009
and subsequently in Cornucopia Issue 26.
© Copyright for this article: Derek Cooper
This article was taken from a copy of Cornucopia that was published in 2010. You could be reading these articles as they are published to a national audience, by subscribing to Cornucopia.