The Long + S tempo?Below is from notes I took at CF seminar
400m runners can follow a similar GPP plan (as per GPP DVD) but the volume of tempo work should be higher, not a whole lot though. For example instead of doing just the long tempo session (2200m) they could do long and short one (1000) to get a total of session of 3200m. Although not a fan of continuous runs they could possibly even a 20 min run before a tempo session although NEVER on the road as it beats up legs too much. A better option may be simply to reduce rest periods of tempo session. Tempo doesn’t have to be an easy session just ensure it is not draining on the CNS and times are less than 75% of best on that surface so if running on grass that will be significantly above what it would be on a track.
taken from http://the-elite-edge.com/main.php?go=viewPost&pID=35