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

When you are going upstairs, you are lifting your whole body up with your legs against gravity. When you are going down, you kind of just drop and catch yourself with gravity being your pal instead of your enemy.

Similarly with hills, climbing ropes, etc.