I certainly have no idea what this thread is about at this point (haha), but I’ve enjoyed the exchange. I think sirpoc’s approach is probably what most people associate as the emphasis of this thread? There have been a few of us to suggest that if the Norwegian approach is just broadly considered more emphasis on a range of threshold paces for workouts, as opposed to just LT or the “traditional” approach of one LT and one VO2Max session per week, that has proved more sustainable and beneficial performance wise. Obviously, this is nothing novel, but I don’t think anyone has made that claim?
I agree that unless carried out in a very controlled manner, it’s hard to know if our improvements come from specific changes in training versus the accumulation of training benefits from consistency, accrual over past seasons, maturation, etc. However, and I can only speak for myself, when I have shifted to a more traditional approach (one LT session and one VO2Max session per week), I see a drop off in performance and feel burned out. I personally would prefer the traditional approach, both for the aesthetic appeal of how it looks on the calendar and the variety in workouts. One long run, one tempo run, one interval session. That has a nice feel to it. However, it just hasn’t proven as beneficial for me as one long run and two tempo sessions at slower than LT, with the occasional VO2Max session, in general.
Regarding your suggestion on studying responses to training, there has been no shortage of such studies in the research literature. Peter Snell, Olympic gold medalist, who is a physiologist performed a study where I believe the group of runners he used ran easy for 6 weeks and then split into two groups, one which ran two interval sessions per week consisting of 200m-400m for a total of about 4800m and another which ran two tempo runs per week of 30 minutes each. The other runs were all easy. They did this for 10 weeks. I can’t recall what the specific paces were, nor can I find the exact study to check it, but an 800m and 10km test were performed at the end of the easy running phase and then again at the end of the workout phase. At both the 800m and 10km, the interval trained group improved more on average. This was a surprise as tempo runs should have been more beneficial for the 10km.
I remember reading this study and testing it on myself, although slightly modified. I did 6 weeks of just easy volume, 6*60 minutes and 1*90 minutes, then 6 weeks of two 30 minute tempos, then 6 weeks of two 15 minute intervals. During this experiment I maintained a 90 minute long run and 60 minutes easy on the other days. I did my time trials on the track and used a 1600m and 10,000m. I had the opposite result as Snell’s experiment, I ran both the 1600m and 10,000m slower after the intervals than I did after the tempos. Training and performance is quite the perplexing experiment haha