How effective bodyweight squats are for building strength and muscle mass depends on your level of training. When you first start out and you’ve never trained your lower body against a resistance, you’ll gain some strength and hypertrophy your muscles doing only bodyweight squats. Squats are a “must do” for building lower body strength.

Bodyweight squats are great if you have no other option, if you just want to make a workout brutally annoying and also mildly difficult, or if you hate yourself. Otherwise, they are just a recipe for wasted time, establishing poor motor patterns, and not getting many effective reps.