On pages 68-69 in Peter Coe's book Winning Running, he talks about his Zone 2 or "Anaerobic Conditioning" zone. He writes, "In Zone 2, long and medium length runs are not abandoned, but shorter faster runs of 5 to 8km become important...Next, interval training is a very good method of maintaining and improving cardiac stroke and volume. Although this type of work is done using a range of intervals, it is best to separate those into sessions of long or short recoveries...Interval work with short or very short recoveries has a different function. This work is concerned with achieving a much higher tolerance to fast anaerobic running through an enhanced ability to buffer acidosis. This is an essential step towards using much longer intervals at fast paces...and is an integral part of the work in the next two zones." Those next two zones being Zone 3 and Zone 4.
OK, I get that the shorter faster runs of 5 to 8km are like short and medium tempo runs, but I don't see where he gives any specifics about the interval training in Zone 2. I'm guessing this would be something like McMillan's cruise intervals (not Daniels' cruise intervals, since Daniels says run the intervals at T pace, not faster, while McMillan makes a distinction between tempo pace, tempo interval pace, and cruise interval pace) but does Coe ever give any examples anywhere?
I get that Zone 3 is "long speed" and is 2 to 8 minute intervals at 3000 to 10000 pace. I'm trying to understand Coe's distinction between interval training in Zone 2 and the 8 minute intervals in Zone 3. Also looking for long recovery, short recovery, and very short recovery interval training examples for Coe's Zone 2 training.