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

Everyone is right that on the flat you are matching the force of gravity, and on the hill you are doing that PLUS more to climb.

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But theres probably another part here thats more human.. People have a weird habit of holding their breath while climbing stairs. I think its probably a concentration thing. So you are probably not getting any air to power your muscles while climbing them.