Eli5: does it require the same amount of energy to walk a loop, say in the mountains, with very uneven elevation changes and slopes,whether you walk it one direction or the other?

Question

Eli5: does it require the same amount of energy to walk a loop, say in the mountains, with very uneven elevation changes and slopes,whether you walk it one direction or the other?

In: Physics

Answer 1

If you simply sum up the energy, yes.

But that’s not the whole story. You said, “Walk”. When you walk, you can’t recover energy when going downhill. It gets wasted as heat, and you even have to use more energy to catch the energy and turn it into heat (i.e. to not roll down a hill and turn the energy into scrapes and bruises). Depending on the terrain, it can cost you more energy to go down than to walk on a flat plain.

Something similar happens when going uphill. It makes a difference if you walk up a slope or have to climb a near-straight wall.

Nothing is simple with the human movement apparatus, but as a rough estimate, you can say that the direction that has up-slopes and down-steps takes you less energy than the other way around.