I'm reading the PD now, but I don't think it answers this question, nor does a quick search of the forum.
I weight train three times per week, play basketball a few times per week, and grapple at least once. I just ran my first half marathon in SF last weekend, but I felt I over trained for it.
What do you feel is the optimal but minimal amount of running one must do to train for a half marathon? I was thinking maybe a shorter tempo run during the week, and an increasingly longer run on the weekend.