Just curious as to whether the OP has ever actually coached in a high school.
My kid was a very successful high school runner with a couple of great coaches, but it was a small program at a small school, and it was a struggle just to get enough kids to round out a varsity and jv cross country and track team. 90% of the kids were there for something to do after school. Virtually none of them were good runners, most were quite overweight, and most started walking as soon as they were out of sight of the coach.
Maybe your approach would be to just kick all those kids off the team, not sure. My kid trained hard, but because he wanted to, and he worked with his coaches to help him. His motivation was internal.
You might luck into coaching at one of the big high schools that consistently produce top teams and runners - the ones that are at NXN year after year - or the perpetual state championship teams - but distance running is not too popular in most schools. I know - everybody talks about Joe Newton. Most schools are not like that. We currently have about 20 guys on our track team, and 18 of them want to be 'sprinters' because they don't have to run much.
So I'm just curious as to how you would propose handling real world situations like this. Theoretical discussions about pushing high school kids to the max are all fine and good, but all these kids are there by choice and most of them are just not going to do your killer workouts. They will either quit or just not do them. If you say "just let them quit" you are not going to have a team and parents are going to complain. Reality sucks sometimes, but that's just the way it is at most places. Take a look at these typical high school meet results and tell me how many national champions you are going to get out of this group -http://www.arizonatrack.com/arizona/2012_Results/2012_Track/2012havasumulti1results.pdf