How do you calculate calories burn't?

[matt_london]

I am trying to work out how many calories you use when lifting 1 kilogram 1 metre vertically. Is there a simple formula and is it also the same for woriking out how many cories you burn walking up x number of stairs, presuming you know the height?

[gen2]

Work done = force x distance moved

So, since the force required to lift 1 kg is approx 10 Newtons (actually 0.982N), The work done is (10 x 1) Joules = 10 Joules.

Since 1 calorie (with a small c) = approx 4.2 Joules, you have to divide by 4.2.

Since one Calorie (with a big C) = 1000 calories (with a small c), you then divide by 1000 to get the type of calorie quoted on foodstuffs and in diets.

In this case, lifting 1 kg 1 metre will burn up 1/420th of a Calorie. You will have to repeat it 420 times to burn off just 1 calorie.

HOWEVER - the human body is not 100% efficient and more energy will be lost as heat generated in the muscles.

[matt_london]

Thanks - What is the difference in calculating lifting 1 kilo up 1 metre vertically or moving 1 kile horizontally?

[kempie]

Work done against gravity should be the easy part of the calculation since we know (within reason) the magnitude of the force needed to cover the vertical distance.

It is perhaps more difficult to determine (or measure) the forces acting in the horizontal plane since different methods of travel may introduce differing value for friction opposing the travel etc.