How often? what are your thoughts?
Drop sets, 21’s, pyramid, up and down the rack, pre exhaust, etc are all techniques that I use on occasion to break the monotony or when I’m lacking in time. I also find it great to give the muscle a “jolt”.
But, it is never based on a work out. it is a tool I use in conjunction with my program.
love them, use them for iso lifts when progress is stagnating.
So if curls or something haven’t changed much for a while I’ll do some run-the-rack or whatever just to stress them a bit more.
wouldn’t do them every workout though.
I like drop sets for rear delts. Use them at least once per week.