hypotheticus wrote:
So, let's say you have a 14-year old who can run 11.9 for 100m. Does that indicate sprinting potential?
Not helpful to look at one factor in isolation...can that kid also run a 1:54 800? Then no, probably not a sprinter. Just because someone is pretty fast does not mean they are not capable or indeed even better at the distance events. Yes, a 10.x 100m runner is not going to be a great distance runner, but just because a kid can score at your conference meet in a sprint event does not mean that is going to be his ultimate BEST event.
It's more useful to look at a runner's index of resistance—how much they slow down comparing, say, 200 to 400, 400 to 800, 800 to mile. DO NOT make the mistake of comparing this to equivalence charts. All (almost all) high schoolers will convert up poorly because they are aerobically underdeveloped. Compare a given runner's index of resistance to data from his coevals on your team, and runners of his age historically at your program (or others if you're a new coach). If you have a fast kid who is unusually resistant, question whether he is really a sprinter.