Probably asked before but the thread is so huge it's hard to search.
Where are we on cross training under this method? Given that the easy runs are super easy so that you are recovered for the next subT session, could you safely replace with bike/elliptical?
Weekly schedule -> 10x3min SubT, 1 Hour Z2 Zwift Bike, 5 x 6min SubT, 1 Hour Z2 Elliptical, 3 x 10min SubT, 1 Hour Z2 Bike, Long Run.
Obviously it's only 4 runs overall but given that the easy runs in this method are so slow and kind of useless, surely an equivalent HR zone x-training method could work?
What are the downsides to this concept?