it seems like you hear a lot about guys being successful when they move up in distance in college or as pros, but i was just wondering who some good examples are of guys who started their careers running longer distances but found greater success when they moved down. i ask because i've always considered myself a 5k type guy with good speed, but my coach, who is pretty knowledgeable, wants me to be a miler, so i'm looking for a few encouraging examples of guys coming from distance-type backgrounds who ended up having success in the middle distances, and who were able to develop their speed in order to be competitive. accounts of elites and personal anecdotes alike are welcome.