Why does pedaling up hill feels harder than walking up the same hill?

Question

Why does pedaling up hill feels harder than walking up the same hill?

In: Physics

Answer 1

Stand on a hill and place a wheel on a hill. You will notice that your feet stay in place, but the wheel will naturally roll down the hill without any additional force.

A bike wheel is designed to be as easy as possible to gain momentum, but that goes both ways. When you are riding a bike uphill, in addition to applying forward momentum, you also have to counter the natural backward momentum of the hill. You will run into the same problem with sleds or skis.