Do Squats Work Abs? Muscle Activation Explained

published by: Debbie Luna
Last Updated:
May 25, 2022

The squat and its many variations are widely known as being leg building exercises that place a particular focus on such muscle groups as the quadriceps femoris, hamstrings, glutes, calves, and other lower body muscular structures.

However, a lesser known benefit of squats is in its capacity to contract the muscles of the abdominals, thereby reinforcing torso stability, burning calories and improving abdominal area definition.

In short; yes, the majority of squat variations do indeed work the abs, and to a rather impressive extent for an exercise meant to train the leg muscles - although the mechanics behind this, in what manner they are worked as well as to what extent said abs are activated may be rather circumstantial.

What Muscle Groups Make Up the Abs?

Despite common belief, the abdominal muscles are in fact more than the six individual muscles that make up the rectus abdominis - also known as the “six pack” that is visible in persons with rather low levels of body fat percentage.

ab muscles

Apart from the aforementioned rectus abdominis are the external and internal obliques that layer atop one another on both sides of the waist, the serratus anterior that is responsible for adducting the arms and moving the scapula and the so called “inner abs” that are otherwise known as the transversus abdominis, beneath the rectus abdominis.

Each muscle group that makes up the abs is responsible for a variety of angles of motion and may be contracted to a certain capacity in practically every possible movement of the body, with the squat in particular activating all of these muscle groups in an isometric, eccentric and concentric capacity.

Are Core Muscles and Abs the Same?

When a piece of fitness related literature speaks of “core muscles”, it is in fact referring to far more muscle groups than simply the aforementioned abdominal muscles, with such muscle groups like the erector spinae, hip adductors and serratus also being included in the core muscles.

As such, while it is true that squats are capable of inducing training stimulus in the abdominal muscles, to say that they train the core to a significant extent would be a more appropriate definition.

Squats and Core Training

The core muscles - especially including the abs - are primarily responsible for stabilizing and protecting the trunk of the exerciser, aiding in reducing the risk of injury, allowing other muscle groups to output more force and generally allowing for a full range of motion to be achieved during an exercise.

barbell full squat

This is all the more noticeable in heavy and unstable compound movements such as the squat, wherein the exerciser will rely on their abs, hips and back to a great degree throughout the entirety of the squat’s form.

Such a usage of the various core muscles will undoubtedly result in a modicum of induced training stimulus over time, marking the squat as one possible way to improve the strength and appearance of the many core muscles.

In particular are the abdominal muscles, of which are contracted in an isometric capacity to a significant extent throughout the squat, wherein they ensure a neutral spinal curve is maintained and that the exerciser’s torso remains in an upright position so as to retain proper form.

Squats and Abs Training

As the term “abs” refers to a group of muscles instead of a single particular muscle group, it should also be noted that the squat trains more than simply the visible rectus abdominis that lies at the front of the abdomen.

Other abs muscle groups stimulated to a significant extent by the squat are the transversus abdominis located deep beneath the rectus abdominis, as well as the external and internal obliques that aid in stabilizing the spine and allowing lateral flexion of the torso.

The intensity and manner of activation for each muscle will vary throughout different portions of the squat’s form, such as the rectus abdominis being isometrically contracted more considerably during the second half of the repetition as the exerciser raises themselves upwards.

What Variation of the Squat Trains the Abs/Core the Most?

For the most part, all variations of the squat are capable of training the core to excellent results - however, a few of these place more stress on the abdominal muscles in particular, thereby resulting in greater developments in the appearance and function of said abdominal muscles.

Generally, variations of the squat making use of free weight sources of resistance such as a barbell squat or kettlebell squat will place the greatest amount of training stimulus on the abdominal muscles as they are forced to activate more strenuously beneath the added resistance.

how to do a kettlebell sumo squat

Delving deeper into this, one may see that certain kinds of free weight squats that require the exerciser to retain a particularly upright torso are the most conducive to core muscle group activation, such as what may be seen in the front squat and zercher squat.

What is Isometric Activation?

Isometric muscle activation is a form of muscle fiber recruitment wherein the fibers of the muscles do not noticeably elongate or shorten, but nonetheless contract in a fashion that is primarily meant to stabilize and reinforce various other tissue structures in the body.

In the case of the abs being activated during a repetition of the squat exercise, it is in isometric contraction that one can see the most activity - with the abdominal muscles barely contracting, even as they are braced throughout the entire movement.

Though isometric activation of muscle groups is noted for inducing certain positive adaptations in regards to the function and size of said muscle groups, dynamic movement such as in eccentric or concentric contraction is considerably more efficient at inducing much the same positive adaptations in greater capacities.

How Does the Squat Compare to Direct Abdominal Exercises?

As was mentioned in the previous section of this article, the squat and its variations primarily activates the abdominal muscles in an isometric or static capacity, whereas the muscle group does not elongate or contract in any significant manner.

Though this is capable of inducing some level of muscular development, it is still not as effective as direct muscle group isolation exercises that utilize dynamic movement in order to induce a training stimulus, such as would be the case in a leg raise or crunch.

weighted crunch

However, this does not equate to the squat being inferior to certain direct abs isolation exercises that also utilize isometric muscle group activation, such as in the plank - allowing said plank to reinforce the training stimulus already presented by the squat itself.

The Verdict - Do Squats Work Abs?

Yes, squats do indeed work abs - though they should not be solely depended on to induce sufficient enough training stimulus in the core muscle groups.

As many athletic coaches and personal trainers would advise, combining heavy compound movements that contract the core muscles alongside specific isolation exercises that supplement the training stimulus provided by these compound movements will result in far better physical development.

For exercisers with a particular focus on the strength or appearance of their abdominal muscles, they may perform a variety of supplementary abs isolation work in combination with the isometric training stimulus of the squat so as to reach their training goals.

References

1. van den Tillaar R, Saeterbakken AH. Comparison of Core Muscle Activation between a Prone Bridge and 6-RM Back Squats. J Hum Kinet. 2018 Jun 13;62:43-53. doi: 10.1515/hukin-2017-0176. PMID: 29922376; PMCID: PMC6006542.

2. Joseph L, Reilly J, Sweezey K, Waugh R, Carlson LA, Lawrence MA. Activity of Trunk and Lower Extremity Musculature: Comparison Between Parallel Back Squats and Belt Squats. J Hum Kinet. 2020 Mar 31;72:223-228. doi: 10.2478/hukin-2019-0126. PMID: 32269663; PMCID: PMC7126258.

Debbie (Deb) started powerlifting and Olympic lifting in High School as part of her track team's programming; She continues to train in order to remain athletic. Inspire US allows Deb to share information related to training, lifting, biomechanics, and more.
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