Ten...I had the snip, a few years back, then went on a winning streak of 5 races, including a couple of steeplechases during the summer so see it as a running aid, I was back out on the trials in 5 days and hurdling in a week.
Oscarr, my most successful marathons have included a marathon distance training run and quite quickly around the 3:10 mark. I think it helps mentally going into the day as you don't fear the distance and it doesn't seem to have a detremental physical effect. I know I'm swimming up stream on this but there are a few of the real elite that do it too. Did you do it on the build up?