Even if one exercise uses more muscles, it doesn’t make the target muscle bigger than a simpler exercise if you train just as hard.

Compound exercises involving greater total muscle mass do not produce superior hypertrophy in target muscles compared to isolation exercises when training volume and effort are equated.

Total training volume, training intensity, and consistency are more significant determinants of muscle hypertrophy than the specific muscle length at which training occurs.

Changing up your workout routine all the time—like switching exercises every week—won’t make your muscles grow bigger than sticking to the same routine, even if you do more total work in the varied version.

If you lift light weights for more reps or heavy weights for fewer reps—but do the same total amount of work—you’ll grow your muscles just as much either way.

No matter which way you measure muscle growth—whether you count all non-fat weight, lean tissue, or just skeletal muscle—you get pretty much the same result when guys lift weights. So, you can use any of these methods and still track muscle gain accurately.