I will almost certainly be in the minority on this issue, but I think most elite high school track distance runners are overtrained in either quality or quanity, and often both. The ability of athletes to take the kind of hard work elite runners take differs greatly from person to person. This is true in virtually every sport. For every Nolan Ryan there are thousands of arms busted each year in spring training that never recover. For every Bil Rodgers and Frank Shorter there are runners like Dick Beardsly or others who had great talent but managed just one or two quality marathons. A lot of long term physical problems derive from cumulative work. What you do in hard work when you are 16 years old might not hurt you then, but it may contribute to later problems. I would suggest that most truly talented track distance runners would be far better off being undetrained in high school and running a 4:08 in high school than training excessively hard and getting down to 4:02. The difference may not appear until they are 23, 24, or even older. Undertraining talented high school athletes who compete in events where they could reasonably peak in their late 20 or early 30s will serve them well as they will be more likely to be able to do the really hard training when there is the bigger payoff in running fast. Slow steady progress and increases in work load is the way to go to achieve maximum results.
G_D