Run far enough and eventually your legs will scream at you to stop. While it's impossible to eliminate this inevitability, weight training can prepare your quads, core, and other muscles to withstand the beating.
The Long Run/Hike
The plan's key workout, the long run, teaches you to make "relentless forward progress," the secret to finishing an ultra. If you're already on a marathon plan, "stick with your current weekly mileage and just start adding time to your long run," Fingar says. "Your goal is to teach your body what it's like to be on your feet all day."
Even elites rarely run an entire 50-mile race, especially off-road, so it's imperative to incorporate some walking into your training runs, says Torin Dewey, a Leadville Trail 100 finisher and coach with Fast Forward Sports in Boulder, Colorado. "Your hiking muscles are different from your running muscles," he says. When to run versus hike will depend on the terrain, but a 60/40 ratio of running to hiking is a good rule of thumb, says Fingar.
If possible, do your long runs on trails. "You can recover faster when you run on a soft surface," Fingar says. "Pavement pounds your body to the core."
Without enough rest, long runs will make you tired, not stronger, says Fingar. That's why she tells beginners to take a rest day before long runs and another one afterward. If you're up for it, try running or walking a few miles the day after the long run to train your body to keep going on sore legs. But if in doubt, stay in: A rest day will never cause injury, but a run if you're not recovered might. Begin tapering
50-Miler Training Plan by Christie Aschwanden