The Squat is a compound, full body exercise. You Squat by bending through your hips and knees, with the weight on your upper-back, until your hips come lower than your knees (“breaking parallel“). Most people think of Squats as a “leg exercise”. Your hamstrings, quads, glutes and groin are indeed the prime movers when you Squat. But your abs, obliques and lower back muscles work to keep you from collapsing under the bar. Even your arms and shoulders must work to keep the bar in position.