This last response of Nobby had inspired me to post again (even though I am following this thread meticulously) after a long layoff.
Let's suppose I'am through with my conditioning phase, and now I am in the 6 weeks long hill conditioning/anaerobic introduction phase. How can I keep my (now) very good Anaerobic threshold, when no tempo-type pace is done? I mean, if you stay out from threshold runs for 6 weeks, it will for sure show up on your state of preparedness. Isn't it true? That's one of the important traits of Daniel's system- T pace is being done even in the late peaking phase.
What is your stance on effect on LT for 5k-10k runners in this 2nd phase?
I'm pretty much in the exact hypothetical place you suggest, but I'm mid-way through my second week of four in the hill phase. If you are on a pretty good hill, and working three or four times up it (for 3 minutes or so on the up), you will definitely feel the effort. The heart rate goes up, and the exertion of bringing the knees through and up combine to make a very strong (but still aerobic) workout, which feels pretty close to a "tempo-type" pace in the lungs and legs. I personally feel that doing this three times a week at 10-15 minutes of effort a session would maintain your state of preparedness. Just an opinion from someone "in the trenches" at this point.