When I'm off cycle I do High Reps (twenties) + Low(heavy) Reps for muscle in one session. But when I become on cycle I strictly separate it.
It looks like this:
day 1 - Chest (LR) + Abs (HR)
day 2 - Back (LR) + Triceps (HR)
day 3 - Shoulders (LR) + Biceps (HR)
day 4 - Legs (LR) + Calfs (HR)
...and now reversely...
day 5 - Chest (HR) + Abs (LR)
day 6 - Back (HR) + Triceps (LR)
day 7 - Shoulders (HR) + Biceps (LR)
day 8 - Legs (HR) + Calfs (LR)
day off is best between Back Day & Shoulder Day IF some
magical on it is changeability followed by lots of positive stress in short time.
specially arms grow like crazy on this one because : example: biceps is trained heavily with 3-7reps-everything back workout (like secondarily helping muscle) on first day and pumped up by 20reps-everithing on regular biceps workout next day. The same with Triceps (with chest secondarily). Small groups 2 exercises & Big muscles 3 exercises. 3 sets.
Even the muscles hurts next day differently after HR day and LR day - maybe red and white muscle fibers ?