Props on the marathon....serious stuff!
I haven't personally had alot of experience with distance running (max I have ever ran was maybe 7.5 miles), but what you are saying makes sense. I would think that your immune system would really take a beating if you were doing that much cardio without adequate rest...not to mention the weight training would really be an uphill battle with catabolism considering the high cortisol levels....maybe one of those cortisol blockers would help (never researched them/ don't know if they even work). Other than that, rest is all I can say. You must really trying to get lean running that much....I mean I know you have a marathon coming up but whoa! That is alot of running.
