Been training for over 20 years ,I tried them all. For a moment few years back I got cought up with all that theory of taking it easy, not going to failure, keep a rep in the tank, don't stay in the gym more than 50minutes, all that shit(at least to me). And I can say that at least for MYSELF, THAT DONT WORK. What works for me is go in the gym, completely destroy the trained muscle, doesn't matter how :drop sets, RP, rounds, high reps, low reps, volume, everything......just go in and train till the muscle is fully done and reach failure multiple times, can take 45min, can take 2hr, I don't watch time no more. I truly enjoy every workout .That's what works for me.....