twinmommaplusone, Congrats on your marathon!!
I have read on runners forums and in magazines that runners do gain about 10 pounds while training. There's seems to be an amount of running that really helps shead the pounds, then I guess at a certain point, not so much.
I run about 3-5 miles like 3-4 times a week, and a long run only every other week or so, and I don't really go that long on a long run.
Mostly because of the weather and lack of day light now.
Congrats again!