The first two weeks are euphoric. You're motivated, your legs are fresh and you feel invincible. But by day 13 or 14, when it's monotony, the day's run has been exhausting and the couch is just around the corner, motivation tends to disappear. That's when [...]

That's where discipline comes in.

I've learned that motivation is an emotion (it comes and goes), whereas discipline is a decision. To succeed in this challenge, I have to eliminate internal negotiation. I no longer ask myself: «Will I run today? The question no longer exists. It's simply: »I'm putting on my shoes.«

Key lesson: Discipline means doing what you have to do, even when everything inside you is screaming at you not to.