The training needed for the Volcano Marathon is similar to that of a regular road marathon. However, it's important to note that the Volcano Marathon presents additional challenges. Over a quarter of the course involves running on dirt roads, ascending an active volcano, and entails a total elevation gain of 4,300 ft (1,300 meters).
There are a wide range of training resources and plans for marathon preparation, typically spanning 15-20 weeks. Here are a few examples to consider:
Training plans from REI
Training plans from Runner's World
Trail marathon training from Run Trails
Elevation chart of the Volcano Marathon.