Having read Daniels' running formula, I haven't seen a word devoted to fartlek and progression runs. Surely, Daniels writes about quick ST at the end of an E pace (for example), but there's really nothing about distinguishing between ST and progression runs. Who knows, why? (plz, don't write "Jack Daniels")
Does Daniels find the described above types of training (FR, PR) useless or has the approaches to training runners changed so much?
Interested to read any answer, thanks in advance!