>Cross Training>Triathlon/Marathon training question
In your case they are pretty far apart. You should be able to get a lot of biking in before your marathon training really picks up. I would follow your marathon plan and bike on your day off, maybe replace the easiest running day with a bike ride or turn it into a brick workout. I wouldn't skip any runs to swim unless you don't have any extra time to do both.
Triathlon training works great for me in preparation for marathons.
For the running, I've been following the FIRST marathon program: http://www.furman.edu/first/fmtp.htm
The program is on their website. I also bought the book which give more detail.
What I do is run only three times a week, but three quality workouts: 1 tempo, 1 intervals and 1 long.
The easy run days you have in a usual marathon training plan, you can replace with cross training. I joined a local triathlon club I do my swimming with (2 x 1h30) and try to fit 2-3 bike rides a week with one longer one on the week-end.
I find that combination easier on the legs and helps avoiding injuries. I end up doing much more cardio training with less strain on the legs and it helped me get better marathon results.
For the swimming, I suggest either joining a triathlon club or check your nearby pools for master swims.
Thank you for the great suggestions! I will check out the FIRST marathon training programs. I've managed to stay healthy and increase my miles, but it seems this eventually takes a toll on my body and I always end up injured. I'm thinking xtraining is the way to go!
Good luck to you all on your xtraining/running goals!