Marathon Training

I don't have a specific plan that I train by in preparation for marathons. There, I said it, and I feel like a load of guilt has lifted from my shoulders. But I should explain I suppose.
I run 10 km four mornings every week, work out in the gym two mornings, and run 20 km once a week. That's it. I run faster or slower depending on how I feel, weather conditions, etc. I change up the gym routine a bit here and there, but concentrate on upper body and abdominal stuff with a 20 minute stationary bike ride at the end as a bit of a treat. Used to get the odd squash game in there but haven't done that in a very long time. And now that the office is on the fifth floor, I take the stairs in both directions Monday through Friday (and I do that emphatically after getting stuck in the elevator for 3 hours a couple of weeks ago).
I read the marathon training plans. I agree wholeheartedly with the science that goes into the creation of those plans. However, my running and gym routine fits comfortably into my schedule and I seem to get through my four marathons a year quite well. So I'm definitely not knocking the idea of going with a plan; I strongly recommend it for everyone, especially beginners, because it gives you the structure for your training that is critical. I just believe that you have to tailor everything you do in life that's important and worthwhile to your own circumstances and comfort level to ensure that you keep on doing it.