PHAT is a solid routine.
My coach is Neil Hill and he has me using his Y3T split. It breaks down as 3 week cycle, which repeats over and over again. The idea, is to target all 3 types of muscle fibers on different weeks.
Week 1 = 10-12 rep range at heavy weight with slower negatives and eccentric hold.
Week 2 = 14-18 rep range of lesser weight, with the aim of a longer “time under tension”, such as 3-4 second negatives.
Week 3 = This part blows. I did 700+ total reps for Legs today. The idea is to utilize Giant Sets/drop sets of higher reps (much lighter weight of course), to be able and hit the total rep range per giant set. They consist of 4-5 exercises. My quad giant set went like this today. I did this 5xs before moving to a similar split for hammies/glutes.
[Giant Set = Leg Press (80 reps) / 30 Body weight squats / triple drop set of leg extensions for 15 reps each / and 30 lunges]. No rest in between each exercise and 2min of rest between giant sets. Its very humbling to be using 180lbs on leg press or leg extensions with 40lbs! Haha.
It sounds silly, but it is incredibly challenging. After a while, I think it helps to throw in some wrenches to your training. If we aren’t improving somehow, then we really wont progress as much as we’d like.