Twenty weeks to your first marathon, and the length of that is the point. There is no shortcut to 26.2 miles. What there is instead is a long, patient build that starts from a long run you can already handle and grows it to 20 miles, with enough cutback weeks along the way that you arrive at the start line intact. That last part is what most first-time marathon plans get wrong. You run 5 days a week. A recovery run on Monday, an easy run midweek, another easy run on Friday, and the long run ...