Lets Run obviously needs more clowns asking what they could run in an all-out effort for a variety of distances. What could I run for a pretty flat half marathon? I've run 15:56 for 5k and 9:50 for 3200, so I think I lean towards the distance side. I do 50-60 miles a week off of 7 days with relatively low intensity and 10-13 miles for the weekly long run.