Bob:
The fact I had not responded shows (1) all the good answers been already presented by others (2) because I read slow, it takes longer time to respond (3) because Lydiard/Daniels thread is almost dea, I don't check this board as often or (4) I simply don't give a damn. The answer is actually all but (4).
First of all, the answer to Paul; training approach for high school runners in Japan, in my opinion, is way too much. My daughter (13) plays basketball. Her team practices twice a week; an hour each. In Japan if you join a club, you'd practice 5 days a week (every school day) and quite often on weekend as well--this by the way is year around. There is a good thing and a bad thing for this (in my opinion). The bad, obviously, is the burn-out syndrome. You could not how many "great" high school runners don't advance in Japan. The problem in the US is (1) stupid rule that don't allow coaches/athletes to condition during the off-season; and (2) too many competitions. Problem in Japan is training too intense. They perform at very high level. I went to Pan Pacific Youth T&F one year. 800 and up, Japan ABSOLUTELY dominated. You even see Japanese junior females running very well at junior section of world cross now. But they (those who actually perform well) don't seem to advance. There was this young lady who won the bronze at world XC a couple of years ago. She went on to university and now she can't even place at collegeate champs. A high school boy who ran within a half a second to the national 1500m record (which doesn't mean much) went on to college and the same story--can't even place at collegiate level. So we have the same issue as the US as far as high school super stars burning out. The good is the second tier kids would gain tremendous conditioning because the concept is accepted. Many high school kids join T&F team but only train half-heartedly (5+ days a week, year round), couldn't quite make it to the national high school champ but went on to be a great runner.
In general, Japanese high school kids to mixture of training (as Lydiard would have put it). But when they DO go for a long run, they go quite far. Even I went on up to 30k when I was in high school. But they also perform way too much anaerobic repetitions and counter good condition they build.
All the main advice that I would have recommended have already been pointed out by others (go for a long easy run) but one thing I would add is to work on speed. For one, it's good idea to "live like Africans" and have young kids run to school barefoot and run back but realistically that ain't gonna happen. Kids who are interested in running would join T&F or XC team and they would invariably compete; then welcome to twice-a-week competition schedule of the US. If they never perform well, they'll lose interest. They need to perform relatively well to stay enthusiastic. I believe the way to apply the Lydiard principles to high school level is not to follow the Lydiard program of 10-week conditioning; 4-week hill phase; 4-week anaerobic training and 6 week coordination. Throw that out the window for now; but let's keep the principles. Have them do lots of easy jogging, as others have suggested; and include some hill exercises (not necessarily concentrated effort as Lydiard had laid out) and sprint drills and other short, sharp sprint work. This is quite different from repeat 400s or LT runs or anything like that. I'm talking about pure speed training. I believe you need to work on "speed" at farily young age.
Throw some time trial at 2/3 the racing distance a few weeks before "season" starts and from then on regular competition would take care of itself for anaerobic development and coordination. Make sure, if you compete twice a week, one of them should be taken less seriously and use it as "fun" thing (why not do triple jump for a change?) or "developmental" competition (why not 3200 for a sprinter or 200m race for a distance guy?). Would that screw up a local ranking? Oh, well, that's not my problem! I believe one of the reasons why East Germans were so successful (besides pills and needles) was this multi-event program for ALL athletes. Drechsler competed 200 AND long jump (didn't she place high or even medal in 100 in 1988 Olympics?); and El G ran 5000 as a youth. Coe ran XC as well as 400. Snell competed in 400 quite regularly. Viren in 1976 competed in 1500m in Europe before Montreal and so did Bauman before Barcelona. While I think Mike Stember competing in 800 to be a better 1500 at that stage of career was wrong, I think it would be a great idea for younger athletes.
I've been involved in kids running here in MN locally. One of the biggest headache is how to make it fun for kids. One of the best things, somebody else mentioned, is to have other kids take the lead and whatever the pace he/she runs, everybody else follows. Some run fast and others run slow. It's a form of fartlek and it works really well. But I also noticed some kids actually really like to just RUN. If you let them, they'll run and run and run at whatever the pace they feel comfortable with (they never even check their heartrate or LT speed!). And you know what, when I accompany them and we'll just jog nice and easily, chatting; and when they get tired, they stop and walk till they feel like running again. Now doesn't that remind us of something?