Mixed

To maximize relative muscular effort (RME) and mechanical loading of the knee extensors during squats, practitioners must use deep squat depths (greater than 105 degrees of knee flexion) rather than increasing barbell load, as load has minimal effect on knee extensor RME.

If your goal is to build strong, large quadriceps, stop obsessing over how much weight is on the bar. Focus on squatting deep—specifically, going beyond parallel (past 105 degrees of knee bend). The study shows that simply adding weight to a shallow or parallel squat does little to stimulate the knee extensors. You can use lighter weights and still get a massive stimulus by ensuring you hit that deep range of motion. Conversely, if you want to target your glutes and calves, you need to use heavier loads, even if you squat shallower.