How many effective sets can be done in a single workout?
About 8 to 12
"how did you come up with that number?"
Through my own training, through years of training people and also through the fact that we know there's always going to be a limited number of sets that CAN BE stimulating within any session
Generally speaking, the 8-12 is JUST A RANGE that I think most people are going to fall into. There might be some people who can get away with 15 but I think most likely NOT because of this factor...
IF you cannot progressively overload the last sets in the workout then they are probably just juk volume.
And this is something else most people don't consider. I am talking about how many TRULY productive sets you have in a session. By productive, that means you're still seeing some PO in the last few sets of the WHOLE workout. If you are one of those people who are always in my comments going "I haven't seen PO in this exercise in weeks" and it's last in the session, then it's a good bet that by the time you get to it you've just done too many sets to make those effective.
Where if I stay in the framework of 8-12 sets then I know that all of those are going to be productive most likely.
For example an upper day could be:
Chest - 2 sets
Back - 4 sets (2 for lats 2 for traps)
Delts - 2 sets
Biceps - 2 sets
Triceps - 2 sets
There's your 12 sets.
If it were calves hams and quads it could be less:
Calves - 3 sets
Hams - 3 sets
Quads - 4 sets
That's 10 sets total, and quads could even be 3 making it 9.
The point of training is not do as many sets as you can, but to do the number of truly effective sets that you can within that session.
If you want to do more exercises then you'll have to reduce sets per exercise. But again, the point is to be smart about how you're allocating your volume in the whole session.