Running motivation can be lost pretty easily. If you ask most people, they'll say that staying on the couch sounds better than going running. But running motivation can be practiced and reinforced with a little bit of effort.
How Hitting the Wall Works
First-time and even experienced marathon runners know it all too well: the feeling that hits around mile 20 when your legs begin to give way and you feel as if you would die if you moved another step. What's going on here, and what can you do to avoid it?