I think you should start with walking—five minutes or so—and add a minute or two every day. When you can walk comfortably for 30 minutes, start to "jog a block, walk a block," and build up
. I think that is the fastest any competitive ultra runner has done a marathon. This article says Goggins ran 3+ at the vegas marathon when he was really hurting. Don't know about Goggins, but Ian Sharman is a top ultrarunner and has a 2:21 marathon time. Some ultrarunners just don't do marathons, like Kilian Jornet.
Here is a list of the 3 things that I learned running 31 miles (my first marathon and ultramarathon): Life is a marathon, not a sprint: Endurance events helped me to realize that life is about living in the moment, breathing deeply, and focusing on the simple things. Newsflash Marathon Runners, ANYBODY can run a marathon. All you need is a desire for a hobby so badly you are willing to train for the sole purpose of running 26.2 miles and coming in 958 th place DO: Warm-up before the race. In a shorter race like a 5K, it's a good idea to do a warm-up, so you slowly raise your heart rate and get your muscles ready to go. About 15 minutes before the race start, do a slow jog for about 5-10 minutes, then walk briskly to the starting line . 9.Running ultras in a healthy way takes years and years of tuning your body and listening. Training gently, as hard as you can. It might look soft on the outside, but go try to run 100 miles and you’ll immediately see why the old guard among us exercise ‘excessive caution’. There is more wisdom here than you can see.