Muscles don’t grow evenly—when you train your thigh, the top and middle parts of the front muscle grow more than the bottom, and the side muscle grows the same everywhere.

Muscles don’t grow evenly — some parts get bigger than others, and different muscles in the thigh respond differently to the same exercise.

Not all thigh muscles respond the same way — one part might grow a bit better with stopping short, while another grows a bit better with pushing to failure.

When you train your quads, the big front muscle (rectus femoris) grows more than the side muscles (vastii), even when you do the same total amount of work.

Doing leg extensions with drop sets (going to failure, then lowering the weight and going again) makes the front part of your thigh muscle grow more than doing regular sets, but only in the upper and middle parts—not the bottom or the side muscles.

This study only looked at the front and side of the thigh—so we don’t know if doing more sets helps your front thigh or hamstrings grow more.