I've been training for the full Chevron Marathon. my last long run were 15 miles. 2 weeks before that I did a half marathon because the route is pretty much the same of the chevron so I need it to feel the surfaces under my feet. All was going well until 5 miles of rough surface made me changed my gate so my PT told my was my psoas muscle on the right side. I took 6 days off doing strenght, cycling, elliptical etc so I felt great and did my 15 miles. Psoas and quad were kind of worst and I noticed the second met on my left foot was bothering me. That happened the 15t my PT said no running again when sheecked on my left foot and said is not a stress fracture and certainly I don't have pain unless I pushed on the metatarsal so maybe I am freaking out, Anyway, my psoas, hip and quad are feeling much better. My training plan is the Hal Higdon for novice so the after 2 weeks of no running but doing cross fit of course It would be enough if I divide the 18 and 20 miles in 2 days. I read that some people can make it by doing this. So instead of doing them in one single run they do 10 on a Sat and 8 on a Sun. I have noticed so far that I am not feeling tired at all so increasing the mileage is being really easy. I guess the training I've been doing before plus a few years of running are paying off. Must mentioned I did my transition to barefoot a year and a half ago so my feet are managing very well. Your opinions will be fully appreciate it. So far I just post on another runners blog trying to find some help and more than one said: wear shoes!! lol! I guess they don't understand the feeling of barefoot running, they confused it with wearing vibrams or sandals is the same or using minimal shoes would feel the same. Hmm... Nahhhh!! I won't go back to shoes.