Regarding rep length and amount of rest taken between reps, many variations can be used for peaking. Assuming the runner has an excellent aerobic base and continues sufficient amounts of aerobic conditioning throughout the competitive period, a runner can use either long reps with long rest or shorter reps with short recoveries to fully develop the anaerobic lactate system.

For example, long reps like 400-800's with a full walk/jog recovery will maximally develop anaerobic capacity. But so will short reps like 200's with short jog recoveries (example: 4x (4x200 @ 800 pace/30 sec. jog rest), full recovery between sets.

I've used both of these types of anaerobic sessions with good success. Both accomplish the same thing (maximally develop anaerobic capacity). I use them both for the sake of variety.

Finally, in his excellent book "Running Your Best," Ron Daws suggests running 16-20x400 @ 10k/100 jog during the base phase for higher level runners. This would be a fairly high level aerobic session, but certainly one that a good runner could easily tolerate without compromising volume during the base phase.

Coachc