>>76367780You will grow with just 2 sets of an exercise (per session) targeting a specific muscle provided you performed the set intensely enough. Sometimes, if I feel I the exercise influences CNS very little, I will jack it up to 3 (in the case of side delts) for a little additional bit of gains.
The areas where you see more than 2 sets are either where I am targeting multiple muscles as part of the muscle group (e.g. chest) or areas where I want complete activation of the entire muscle throughout the weekly split (e.g. bicep with short and long head).
The pic is also kind of bad because there's definite spillover of muscles targeted due to effective compound usage. The "lower back" sets also target the glutes and hamstrings, for example, so the volume is deceptively higher than shown.
That's my logic. How'd I do?