Here's the question; is it possible to run a 2:19 marathon off of 55 miles/week when 55 miles is covered in 4 days of running and the other 3 days of the week are spent cross training on an elliptical, bike, nordic skiing, etc.? I'm looking to your thoughts as to what I'd be missing by cross training 3 days out of the week compared to running for my recovery. I have a history of overuse injuries which is why I'm leaning in the direction of cross training for my recovery.
The 4 days of running would be mostly high quality with a rough training schedule looking something like this:
Monday: 60 minutes elliptical
Tuesday: Medium long run at a moderate effort (13-15 miles) + Weights
Wednesday: 90 minutes cycling
Thursday: Threshold or VO2max session
Friday: Easy 45 min run + 30 minutes XT (elliptical, nordic ski, etc) + Weights
Saturday: 70 minutes XT
Sunday: Long run w/ marathon pace work (16-22 miles)
I'm at least 1.5-2 years off from having any chance of hitting a 2:19. I have a HM PB of 1:09:58. I would normally hover around 75 miles/week in past marathon and half marathon build ups but have run a few weeks with 85 miles. Any thoughts would be appreciated!