I have signed up for my first ultra event, Mt Si 50K on April 10th. I'm reading a ton about training and fuel. The most common advice is to run back to back long runs on Saturday-Sunday. This weekend was the mileage build up, Saturday 8 miles with a pace group and Sunday 12 miles on the trail. I managed a swim workout on Saturday as well, building up that base from 800.
I'm investigating the nutrition aspect of this type of training. Dean Karnazes apparently eats whole pizzas.