5-30 reps. You have to try out all rep ranges within 5-30 to see which one gives you the best results. Sets depending on your program. Start with 4. Lower number if you notice you can't recover in time, increase number if you recover too quickly, or if you want more growth. Bodybuilding is highly individual, track your numbers, soreness and physique in the mirror and plan/change accordingly.
Use in pre-exhaust training. Do it first to work back only then without any rest do multiple joint exercises like pull-down, or row exercises that many muscles totally exhaust back. Shoulders arms even chest muscles work together to fry back. Works very well for me .
