The hack squat is a machine-based exercise that targets the muscles of the legs, particularly the quadriceps. It is often used as an accessory for squats, but can also be the main lower-body movement in a workout. It is often performed for moderate to high reps, such as 8-12 reps per set or more.
Builds size and strength in the quads, glutes, and hamstrings
Great heavy movement or lighter-weight burnout
Changing foot placement or toe angle can change the emphasis of the exercise