A lot depends on your natural ability.If you are an average runner running relatively easy mostly flat courses as your regular running route, when you get to a 10 - 13 mile comfortable regular run, combined with occasional extender runs (aka long run), you will be in good shape to finish a marathon in a fashion that you will enjoy the experience. You will know when you have reached a base distance when, on a run, you have the comfortable and enjoyable feeling to extend your distance beyond that which you have based. In other words, if you have done four 7 mile runs and on the fifth one, you just don't "feel" like you have gone far enough and have the urge to go 8 miles that day, then you will know that you have based at 7 miles. So, the progression will go until you are again dissatisfied with the 8 miles and "feel" to stretch it 9 miles.
If you are running on a course with a lot of long steep hills combined with short roller coaster hills, and 8 or 9 mile run on this kind of course can be equivalent to a 11-12 let's say on a flat course.
Post a reply on the Bulletin Board