And yeah, it’d almost certainly depend on individual mechanics/leverages. If you’re a tricep-dominant bencher, you might benefit from flyes or DB presses to hit the chest; if you’re someone that doesn’t tend to use a lot of “bicep” in a pullup/chinup, then you might benefit from curlz. And I’m sure there’s plenty of other examples to go around.

Of course, the problem is that it’s hard to actually measure tension development, so without some lever measurements and trig (which I’m way too math-inept to try) it’s hard to say which might actually create “more” tension: a compound movement with relatively heavier weights, or an isolation movement with lighter weights but putting more stress on the target muscle.

In short: use some of both if you’re after muscle development.

That is, if I’m benching, the stress is spread out across pecs, delts, tris, and everything else.

If I do flyes, it’s pretty much 100% on the pecs.

Can you be sure that the actual tension seen by the pecs is higher in the compound movement?

Does it depend at all on the mechanics of the trainee?

Lyle