Squats contribute to abdominal and core strength, but not like traditional exercises such as crunches. Squats are not designed to be a primary builder of the superficial “six-pack” muscle, the rectus abdominis, through dynamic movement. Instead, they are highly effective for developing the deeper muscles of the torso that provide stability and a foundation for all other movements. This distinction lies between core strength for stabilization and core strength for movement.
The Core’s Role in Stabilization During Squats
The core’s primary job during a squat is to act as an isometric stabilizer, resisting movement rather than creating it. This stabilizing function is especially pronounced under heavy external loads, such as when using a barbell. The muscles contract without significantly changing length, which is defined as an isometric contraction. This provides a different training stimulus than the dynamic, shortening contraction seen in a sit-up.
The deepest abdominal muscle, the transverse abdominis, plays a major role in this stabilization, acting like a natural corset to increase intra-abdominal pressure. This pressure provides internal support for the spine, helping maintain an upright posture and preventing the torso from collapsing forward. The internal and external obliques also engage significantly to resist unwanted lateral flexion or rotation of the trunk. Research suggests that the engagement of these muscles during loaded squat variations can be similar to that achieved during a prone plank.
Primary Muscles Activated During Squats
The squat is fundamentally a lower-body, compound movement designed to move the body’s center of mass vertically. The greatest amount of muscle activation and load is focused on the large muscle groups of the legs and hips. These primary movers are the quadriceps, which extend the knee, and the gluteus maximus and hamstrings, which extend the hip.
The quadriceps are the main power drivers, particularly during the ascent phase of the lift. The glutes are a major force in standing the body up from the bottom position. While the core is active, its role is secondary to these powerful muscle groups, which generate the force to move the weight. This focus on large muscles is why the squat is categorized first and foremost as an exercise for building leg and hip strength.
Maximizing Core Engagement Through Technique
To maximize core benefit from squatting, technique must emphasize intentional bracing. Bracing involves creating tension around the entire midsection, as if preparing for an impact, which activates the deep stabilizing muscles. This is achieved by taking a deep breath and forcing the air down into the abdomen before descending, then tightening the abdominal and lower back muscles.
Specific squat variations can dramatically increase the demand on the core stabilizers. For instance, the Front Squat, where the barbell rests across the front of the shoulders, forces the torso to remain more upright than a traditional Back Squat. This forward load placement requires a greater isometric contraction of the upper back and anterior core to prevent the chest from dropping.
The Overhead Squat, performed with a barbell or object held directly above the head, is perhaps the most challenging variation for the core. Maintaining the vertical bar path requires extreme stability and coordination from the entire trunk, challenging anti-flexion and anti-rotation capabilities simultaneously. Even without heavy weights, the Goblet Squat, where a dumbbell or kettlebell is held against the chest, increases anterior core activation and helps reinforce the upright posture needed for bracing.