Wow, I think I touched a nerve, or uncovered a deep-seated self-doubt. Considering the Op stated, "If you catch a stress reaction early whats the minimum time you can be out of running . . . " (sic), I gave him my answer, based on "catching it early." You, et al., had the guy in an air cast, out for 4-plus weeks, stressing (no pun intended) out over a potential stress fracture, while still "catching it early." Given your advice, I would not have run the 48 joyful miles I just completed Mon-Fri. My Saturday run was very, very bad, multiple sharp pains in the shin, after a previous build up of your typical "stress reaction" or "shin splint" or potential "stress fracture" or whatever it is or was, given that I am a lawyer, not a doctor. I took one day off, and, voila, 48 more miles under my belt. I'm just trying to give the OP another way of looking at life, my friend. You, on the other hand, would have him racking up his health insurance copays, and getting a massage and a pedicure at the local salon every time he felt the slightest discomfort.