I'm with Wes. Do them both. Why not? That works for me. And some bodyparts, it's just real hard not to hit if you don't do a "compound" lift.
Let's use lats as an example for my argument.
Which exercise can take the lats from a fully stretched position, to a contracted position? Like, a nice full ROM?
If you say "pullovers", I can type out five paragraphs of biomechanic shit to show they're not the best at taking lats thru a full ROM. In short, they don't involve scapulo/humeral protraction under load at full stretch. I digress.
You have to put pulldowns/pullups at the top of the list for lats and the big news headline - those are compound lifts. So, the entire debate of "compound vs isolation" kind of falls flat there for me. You can't even really train a key muscle in the body properly without employing a compound lift.
On the flip side, know any compound lifts that train the calves? You know, any calf exercises where you simultaneously flex and extend at the knee while you dorsi-flex at the foot? Of course not. So, are there really any compound exercises for the calves? None that I've seen done consistently. Or said another way, the calves are trained with isolation exercises.
So, isn't this debate all about "do overhead presses work shoulders better than lateral raises", or "bench or fly". That tired, oft-had debate.
As I've aged and continued to study up, I've come to the following ways of thinking:
1. there's enough published literature now to show that it's reasonable to assume a targeted muscle, taken to failure with enough volume, will grow similarly with a compound lift versus an isolation lift. Notice I said "targeted muscle". Not "all the muscles in your body". We've got cross sectional area measurements on targeted muscle. So, if you want to build pecs, and you like benches, go ahead. Or flys...go ahead. Neither is better or worse for targeting the pecs (notice I said "pecs" only), if you take the exercise to or near failure, with enough volume over the week, with good form, blah blah.
2. there's a case to be made that eventually, Father Time weighs in on your workout. You can try to isolate every muscle in a back workout, but you'd do so much total volume it'd be nuts. You'd do 10 weekly sets just for erectors? Another 10 weekly sets just for the teres major? Another 10 against all three divisions of the lats (all whilst deluding yourself you can isolate each division....). You see where I'm going? You'd just create so much systemic fatigue, and probably it'd be more self flagellation than productive for a back workout. Or, do some pullups and some t-bar rows and be done. The greatest gift that compound lifts give us, is that they save time. And eventually, from a physiologic standpoint, even the most dedicated lifters with nothing but time on their hands have to use them, because the body simply won't allow you to do enough meaningful volume for each muscle, each week, using just isolation exercises.
