Short background: 24 yo, been running for about 2 year during which i've lost 30 lbs and last fall I ran a 2:58 marathon off of around 40 mpw, lowering my pb by 50 min. This year my goal was sub 2:50, but I got a stress fracture when I was increasing my mileage so I had 3 months off from running in the spring. I did a bunch of cross training and still do, so weekly training volume is prob on av 15h. I've just now got back to around 40 mpw running and some decent workouts. Have 3 months until my marathon, so I will have some time to build a bit more, but because of my injuries this year I won't risk high mileage and will prob aim for 3-4 50 mile weeks. Haven't done much speed work though I did 3x1k averaging 3:20. Yesterday I did a 15 mile run with 4x4k averaging 6:20 and next week i'm planning on doing a 20 mile run with 4x5k at 6:20.
What else should I be doing between now and then? Is it better for me to do 60 mpw peak with no workouts, or 50 mpw with a couple hm/mp workouts? Is cross training with rowing better than cycling or elliptical or is it all the same?
Thanks!