After I reach my ultimate marathon goal of sub-2:30:00 this Spring, I think that I am going to move up to ultras. I have no shot at ever qualifying for the Trials, so 2:30 is pretty much the last attainable goal that I have on my "traditional distances" checklist.
Is this a good idea? I have always been interested in the idea and I have pretty decent endurance. I put in about 70 mpw on average and recently ran a 1:13:47 HM. This was on a windy day and I ran foolishly. I probably could've pushed 1:13:00 with a smarter race. Anyways, I was pretty pleased with the time given that my 5k PR (on the road) is only 16:09 and my mileage is not that high.
For what it's worth, I have never experienced injury problems. I currently train 7 days per week, all singles. I have not run longer than 17 miles continuously in about 9 months (excluding the Boston and Chicago marathons). However, I would be willing to put in more miles and better training if I had a shot at Ultra glory. How many miles do I need to run weekly? Should I start doubling? Should I just stick to the shorter stuff?