I am a PhD student and I have always likened the process of getting a PhD to long distance running. You have to step out day after day, build your skills, accumulate the miles, live through injuries and pitfalls, face the weather and come out on that final race day to prove that all the hard work was worth it.
It is a learning and a very humbling experience, one helps you showcase your strengths and work on your weaknesses. At the end of it, you are a slightly better person than when you started. Personally, I have even found running of help in my PhD - it clear my head and keeps the brain agile. The number of instance when I have pounded the road to vent out the frustration of poor results, is better to be kept hidden from the blogosphere.
I found this article really interesting and I reflected again on the metaphor of running - life. Broader than a PhD, but corroborates my theory.
PS: I am back to running and enjoying it like hell! Nothing like Florida weather for running :)