Train Your Way
There is no single right way to train for an ultra. The best training plan is the one you can actually stick to.
Find What Works for You
Training plans are a starting point, not a rulebook. If a plan says run 8 miles on Wednesday but your kid has a game and work ran late, adjust it. Spread your runs across the week however it fits your life. If you have 30 miles to run in a week, you get to decide how to split that up. The goal is consistency, not perfection. No app knows your schedule better than you do.
Build Mileage Slowly
The most common mistake new ultra runners make is adding too many miles too fast. A good rule of thumb is to increase your total weekly mileage by no more than 10 percent at a time. It feels slow at first, but your joints and tendons need time to catch up to your fitness. Building gradually is what keeps you healthy and running for the long haul.
Mix It Up
Running the same route at the same pace every day gets old fast. Keep training interesting by mixing in trails, roads, hills, flat stretches, fast efforts, and slow easy miles. Variety keeps you mentally engaged and builds a more well-rounded fitness base. Personally, I mix in a rowing machine because I enjoy the change of pace and it gives my legs a break without stopping my cardio. You don't have to lift weights if you don't want to. Find the cross-training that keeps you moving and doesn't feel like a punishment.
You Don't Need a Running Background
You don't need years of racing experience to start training for an ultra. Most people in the sport started somewhere close to where you are right now. Start slow, build gradually, and don't worry about your pace. Nobody at an ultra marathon cares how fast you're moving unless you're trying to win the thing. The goal is to finish, and finishing is enough.