The Hack Squat is a compound lower body exercise that primarily targets the quadriceps, hamstrings, and glutes, while also engaging the calves and core muscles. It is performed on a hack squat machine, where you stand on a platform with your shoulders and back against the padded supports. Holding onto the handles, you lower yourself by bending your knees until your thighs are parallel to the ground or lower, then push through your heels to extend your legs and return to the starting position. Hack Squats are effective for building lower body strength, enhancing quadriceps development, and improving overall leg muscle endurance and stability.