Not understanding basics

Physiologically, how does the Sheiko-style of lifting elicit a training effect given that seemingly the majority of the work is done with rep ranges that are significantly below the rep ranges typically associated with the prescribed training intensities - e.g. 80%x3x5? I understand that skill acquisition is important, but it would also seem that being able to induce hypertrophy is also essential, and the assistance work prescribed seems pretty low to moderate in volume. Can someone help me out?

Caveat: There are still many open questions about what specifically makes muscles grow and how much you have to do from what, so the following is more or less to be seen as a somewhat recent snapshot of the current evidence:

- pretty much all weights over a certain treshhold (and which lies below 50%, the question is only, how low can you go) of your 1RM work for hypertrophy
- prime movers (e.g. quads in the squat, chest and triceps in the bench) already get good hypertrophy very far away from failure (say more than 5 reps in reserve), whereas smaller muscles seem to kick in more and more the closer one gets to failure
- it is still not very clear how to accurately count "work towards hypertrophy", e.g. hard sets, certain reps, total volume, total reps, but the general consensus seems to be: do as much as you reasonably can

Given that Sheiko's programming features a lot of volume of lifts of at least 50% (just compare it with traditional "high volume" bodybuilding programs) in the big three, it seems reasonably that you can expect quite some hypertrophy.

Also I think that it might depend a bit on your sports background, if you start powerlifting in your teens (as probably many of Sheiko's earlier athletes), you have plenty of time to grow and will sooner or later max out your potential, whereas someone only starting in his 20s or 30s has a lot less time to gain good muscle and might want to speed that process up a bit by sprinkling in some dedicated hypertrophy phases now and then. But in the end, a small deviation in barpath often means a large increase of some moment arm and it's hard to outgrow such forces.

In case of hypertrophy, I would also think that usually it is more a matter of exercise selection than of programming. For example competition low bar squats may have significantly less range of motion for the quads than full range high bar squats, or a competition bench versus one with a different grip width.