Through the long journey of evolution, humans have become one of the best species on earth at running, especially with long distances. Not only because our sweat glandes help keep us cool while we used to hunt down our prey to exhaustion, but also because of where our main muscles come into effect and how our body enables us to move.
Here is a quick 3 minute video by The Smithsonian Channel showing how our bodies have become so resistant and perfect for running. I know right? Only 3 minutes?! Explaining such a complex topic that involves evolution and our body? Sadly, it's still only 3 minutes (3:23 to be exact), but the video does a nice job at going over a few features that enable us to run like the wind. Check it out: