I am a high school XC coach. For the past 8 years we have had some fairly good local success. I have always used the Jack Daniels Vdot charts and the corresponding paces for intervals and threshold runs. I do take into account the different courses and other factors in placing kids on the Vdot chart. Our weekly schedule during the mid season peak training time is usually ..... Monday, Intervals, Tues, recovery run, Wed, Threshold, Thursday, easy with striders Friday, Race, Saturday long.
Intervals are usually between 400 and 1200 hard stuff adding up to 5k of distance on rolling hills of combined dirt/road-- Threshold is usually 20 min on road. Long runs up to 90-100 minutes.
I am toying with the idea of using Daniels idea of putting the workout days back to back. I was thinking of Monday intervals, Tuesday threshold. then two easy days before the meets. Has anyone used this type of a training plan with high school kids and have success/failures with it?? Or any other thoughts.