A lot to kind of unpack there, so this probably won't cover all of it, but is there a specific reason you'd want to target them?
Worrying about targeting fast twitch vs slow twitch in regards to hypertrophy is probably the wrong direction of focus and also probably not worth worrying about for these kinds of goals.
You can’t reliable predict what your composition would even be and it’s probably better to just use things like markers of how your particular muscles recover to various stimulus than focusing too much on fiber composition for most goals.
Luckily if we get exercises to be challenging enough (close enough to failure) then hypertrophy can be stimulated with huge ranges of reps.
There are some different protocols out there for waving rep ranges, but for hypertrophy varying back and forth between the set may be tough. Building up to a heavy(er) set then doing back off sets with more reps, varying the rep ranges over the workout via different exercises, or if you hit the muscle multiple times per week doing different ranges during different days may be a better way to cover your bases of various ranges.
. You back at training yet?
