Ian Bell wrote:

I think these may be wrong too. it is generally accepted that a human at
rest generates about 100W.


That's about 2000 Calories per day so about right but people generally
talk about the extra energy used during exercise compared to resting.

A good measure is that a fat bloke climbing a flight of stairs uses a
Calorie.
Of course it depends on how fat you are and the dimensions of your office
but it's good enough for your lunchtime exercise calculations.

--
Eiron.