You've got to be kidding. 20 sets and maybe up to 30 per muscle group a week? And maybe even more? Using what, pink dumbbells? Let me tell you, when I was younger I averaged in the neighborhood of 15 sets for the larger muscle groups per week using an ABA BAB split routine. I did it for a good many years. Sure, I got good results, but was it because I was doing so much, or was it despite the fact I was doing so much because I was still young enough to tolerate such volume at fairly high intensity (simple concentric failure)? Even then, over 20 years ago, I'd have to drag my ass to the gym on occasion, not having fully recovered from the last episode. Now, I couldn't get away with that if I tried. And, looking back, I wish I did what I'm doing now much, much sooner. As for Schoenfeld and Krieger, you can have them. Despite what he says, I have it on good authority from an exercise researcher who watched him train that Schoenfeld doesn't train to true failure. As for Krieger's meta-analysis supporting multiple sets, Carpinelli drove a truck through it:
Been doing a 1 set per exercise full body routine for a few months, when reps are high enough, say 10 up, just one warm up set on the main compound exercise works fine (like on deadlift or squat, than the rest of the back and legs exercises don't need warm ups. Warm up for bench press than no more for other pressing exercises). Similar process with higher weigths/lower reps btw, except I add more warm up sets on the main exercises, and might add an extra set with light weight but low rep on assistance exercise if they feel heavy enough. Routine worked great in higher rep range btw, not so much with lower reps as work outs get very taxing when working heavy the same muscle group every session(might be easier for younger folks). My injury prone back more than cringed today during deadlift and sent me looking for tramadol for the first time in 4 months, I might have to give up trying to do heavy DLs, Squats seem to cause less troubles. But a split routine might also be a better idea. It's a hassle though to change station every exercise, I train in a place where they let you do about anything you want , but lacking of barbells, need to go around with my barbell, or go look for a free one when changing exercise. I had also good experience with full body routines but several sets per exercise btw, at least when coming back froma break, it is more convenient to settle in some workstation for a few sets.