I cannot think of a non-hostile application for this.
Like who tf cares that a machine can run a marathon? The only reason marathons are a thing is because they are difficult for humans to do, and the ones who do display a feat of perseverance.
We’ve had self-propelled vehicles for hundreds of years that are way more efficient, so it’s not about transportation. The only practical application I can think of is to make robots that can chase down humans.