We often look to metaphor for guidance in our constant search for the how and why of writing. In an essay at The Millions comparing writing to running, Nick Ripatrazone explains that training is not just an analogy for his creative process but an essential part of it:

Training sharpens ideas by cutting away the chaff that tends to accumulate during that long time on the trail, where the mind can wander; training blurs those ideas to the surreal places where art is made.