why is going up the stairs (or up a hill) so much more physically intensive?

Question

I am not very fit, but I do walk a lot. However when I go up 3 flights of stairs I am out of breath. How come?

In: 0

Answer 1

Going up means overcoming gravity which is pretty strong on Earth, all things considered. Just walking means overcoming air resistance mostly, which isn’t very strong at normal walking speed with no wind.