I am currently ready to run a half marathon in two weeks and after that will continue my training to prepare for the Portland Marathon in October. On my current training plan I have been using mileage goals to train. I signed up for a beginning training program for the Portland Marathon and it is set up by time. I noticed the longest long run is 4 hours long. Currently I run very slowly and I know the marathon is going to take me 5+ hours to complete. I run about a 11:34 mile in training currently. Do I need to adjust my training runs so that I am running for longer periods of time prior to the marathon, or will that build-up to 4 hours be enough to get me through the marathon?
See Jane Run - I Run for Chocolate and Champagne 5k (Boise, ID) 6/19/10
Most beginner training programs only go up to 20 miles. For me, at about a 10 min/mile pace, the difference is about an hours worth of running to get to 26.2. The program you described sounds comparable.