op-ed,
I don't know where you're getting your '2-minute max' idea, but I'm basing my 3 minutes of rest of 6 minutes hard effort from a number of posts here at LRC (using the search function) on the 4 x mile workout. Significant literature I've read suggests a 50% recovery time per running time. Also, this was just what a friend was doing that particular night, so that is what I jumped into.
I know that for Daniels, he does not recommend going more than 5 minutes at V02 max"ish" effort (which is what those 6:05s ended up feeling like in the wind, hills, and undulations of the road etc). So, yes, you are right that 1200s would be a sweet spot for rep work.
I did the mile reps again on Tuesday, and I will do them again next Tuesday. I'm a big believer in keeping things constant for 3 weeks before changing so that I can note increases in fitness or staleness onset.
After that, the staple workout will be 5 - 6 x 1200 in ~4:25 with 400 jog recovery.
To the other poster,
-------------------------
For the most part, I do my rep work and tempo work on a track. I did do last week's 4 x mile on the roads because that is what my friends were doing.
I will preview by saying that on Tuesday, I did 4 x mile with 3:00 recovery in 5:50 (2:56, 2:54); 5:49 (2:56, 2:53); 5:50 (2:55, 2:55), and 5:54 (3:04, 2:50).
I never really go into rep work with a specific goal other than to RUN WITHIN MYSELF and to gradually pick up the effort until my last few reps are JUST SHY of being a maximal effort.