#3: Introduce Long Runs
The long run is something you incorporate in-between base mileage exercises every 7 to 10 days. The long run should increase every occurrence by a mile or two. Then, you start to scale it back every three weeks in order to not overwork your body.
Start small: Running a few shorter races—5Ks, 10Ks, or even a half marathon—is an excellent way to prepare physically and mentally for a first marathon. For more information, see our Expert Advice article, 10K and Half Marathon: Training Tips and Exercises.
Choosing a First Marathon