Has anyone run a sub4 mile on the track in flats? I'm sure a bunch of guys could but did anyone do it. This question all started when I read Ryan Hall was attempting to run a sub4 in the Twin Cities Road Mile. If he does I could see him wanting to get an official one on the track and wondered about injury/harm going from flats to spikes . I guess we must take another step and think about barefoot sub 4 minute miles. .. I better stop thinking before we get to thinking about nude co-ed beer mile videos.