Found this Useful n Interesting Article from Runners World on 50-Milers Trainings...
Here are some extracts...
Training for 50: A few things you should knowYou're not going to spend most of your waking hours running. That's because prepping for a 50-miler is much like marathon training, but with fewer and slower intervals, and somewhat longer (and slower) long runs spiced with walking breaks. Our plan offers enough miles in the proper dosages to prepare you for your first 50, while leaving you with enough time and energy to have, like, an actual life.
Ultra training is not about speed, or even distance, but rather time on your feet. Hence, the core element in getting you ready is the long run "sandwich": back-to-back long, slowish runs on successive days (likely Saturday and Sunday) bookended by two days of total rest.
8 Rules of the road1) Stay flat
Find as flat a 50 as you can, and as close to home as possible. Running this far for the first time is tough enough without the added stress of steep hills and travel.
2) Get familiar
Train on the terrain you're going to race on: trails, asphalt, or--as is common in many 50-mile events--a mix of the two.
3) Take breaks
"Stopping briefly for walk breaks in both training and racing is the key to being able to move forward at all times," says Buffalo Chips ultrarunner Becky Johnson, who finished her first 50-miler in 2003.
4) Pack a bag
Most 50-mile events will drop your race bag near the 35-mile point (some also will make a drop around 20 miles). Your drop bag(s) should include solid fuel (your favorite energy bars, candy bars, or gels), sunscreen, long-sleeve T-shirt and/or nylon windbreaker, clean socks and an alternate pair of shoes, and Vaseline or skin lube.
5) Start slowly, then back off
Because when it comes to 50-milers, pacing errors no longer penalize just your finishing time, but the possibility of finishing at all. "Start off a full 30 seconds-per-mile slower than your marathon pace," says Parrott.
6) Eat, drink, and (try to) be merry
During the race, eat whatever worked for you during your training runs: cookies, raisins, figs, crackers, pretzels, energy bars. Whatever. And drink continuously: eight ounces or so every 15 to 20 minutes, including electrolyte-loaded sports drinks. Consider high-caffeine drinks such as Mountain Dew over the last 15 miles.
7) Find a rhythm
One popular run/walk pattern is to run 20 minutes, walk five minutes. Do this from the outset, or after you've run the first 15 or 20 miles, or whatever pattern has worked best for you in your training. Some prefer a shorter mix of running five minutes, then walking one, believing that this is less stressful than the 20:5 pattern. Note: Walk all uphills, even the small ones, and even if it means short-circuiting a run segment.
8) Be prepared
Just how much time is this thing going to take you? To get a ballpark expectation, double your best marathon time and add two hours to get a realistic 50-mile time. So for example, a 3:30 marathoner could expect to run his or her first 50 in about nine hours.