Here's what you need to know...
- A few studies claim that multi-joint, free-weight exercises such as squats and deadlifts activate "core" muscles better than isolation core exercises.
- These studies have led many people to mistakenly think that all they need to do to strengthen the abs and obliques are squats and deadlifts.
- Subsequent research has shown that squats and deads don't even come close to creating the levels of activation in the rectus abdominis that the push-up does.
- People define the word "core" incorrectly. It's not just your deep spinal stabilizers, abs, and lower back. It's your entire torso minus your arms and legs.
- The Swiss ball rollout and the Swiss ball pike are the most effective in activating the abs and obliques, prompting the author to create the "pike rollout."
For Abs, Squats and Deadlifts Suck
A few studies have taken the position that multi-joint, free-weight exercises such as barbell squats and deadlifts activate "core" muscles better than isolation core exercises.
These studies have led many trainers, coaches and exercise enthusiasts to mistakenly think that you don't need to do exercises that focus on strengthening your abs and obliques because squats and deadlifts do the job more effectively.
The truth is, when you look at the evidence, the common claim that "heavy squats and deadlifts are all you need to strengthen your abs and obliques," doesn't make sense. In fact, the common push-up activates the abs and obliques more than squats or deadlifts!
What does make sense, though, is the "single best abs exercise," which will change your thinking about core training.
The "Core" Is Not What You Think It Is
The primary reason for the misinterpretation of the core activation research? Failing to understand what the "core" muscles are to begin with.
Although just about every trainer, coach and exercise enthusiast talks about training the core in one way or the other, most are unaware that the term "core" was first coined in 1982 by Bob Gajda (1966 Mr. America) and Dr. Richard Dominquez in their book, Total Body Training.
In their book, Gajda and Dominquez described what the core is and what it does:
The first essential concept in total body training is that of the "core," which is our term for the muscles of the center of the body.
These muscles stabilize the body while we are in a correct, antigravity position or are using our arms and legs to throw or kick. They maintain our structure while we do vigorous exercises... These are the muscles that control the head, neck, ribs, spine, and pelvis.
The core of the human body is those muscles that keep the trunk and neck in a tube-like form... When your core is firm and rigid, you can do the activities it's intended to do. If the rigidity is enhanced, then you can maximize your athletic performance.
Put simply, the "core" isn't just your deep spinal stabilizers along with abs and lower back; the core is the entire torso minus the extremities (arms and legs). This means that the shoulders, chest, glutes, abs, mid-back, and lats are core muscles.
So, although you may not think of doing chest presses and back rows as "core training exercises," they most certainly are.
That said, the big takeaway from this is that you need to be strengthening all of the muscles of your torso if you want a strong "core." Keep that in mind as we look at the research on squats and deadlifts as they relate to "core" muscle activation.
A Closer Look at the (Misguided) Science
One of the two studies that are most commonly quoted as scientific "evidence" that squats and deadlifts work better for strengthening your abs and obliques is entitled Systematic Review of Core Muscle Activity During Physical Fitness Exercises.
The purpose of this article was to "systematically review the literature on the electromyographic (EMG) activity of 3 core muscles (lumbar multifidus, transverse abdominis, and quadratus lumborum) during physical fitness exercises in healthy adults."
(You scientific detective types will notice that when the authors say "core muscles," they're not referring to the rectus abdominis and the obliques.)
The major findings of this review were as follows:
- Moderate levels of evidence indicate that lumbar multifidus EMG activity is greater during free weight exercises compared with ball/device exercises and is similar during core stability and ball/device exercises.
- Transverse abdominis EMG activity is similar during core stability and ball/device exercises.
It's clear that the results of this review certainly don't demonstrate that squats and deadlifts create more activation of the rectus abdominis and oblique musculature than exercises that focus on those core muscles.
However, what these findings do tell us is if you're doing exercises like squats and deadlifts, you're not neglecting the deep (local) core stabilizing muscles like the transverse abdominis and the lumbar multifidus.
The researchers concluded that, "The available evidence suggests that strength and conditioning specialists should focus on implementing multi-joint free weight exercises, rather than core-specific exercises, to adequately train the core muscles in their athletes and clients."
Now, if you only read that conclusion, and failed to ask, "Which core muscles did the researchers of this study look at?" you can clearly see how the study was misrepresented as demonstrating that squats and deadlifts create more abdominal activation than core-focused exercises directed at those specific muscles.
Not Even as Good as a Push-Up
Another study that often gets misrepresented is entitled Trunk Muscle Activity During Stability Ball and Free Weight Exercises.
In it, squats and deadlifts were done with loads of approximately 50, 70, 90, and 100% of the subject's 1RM. Subjects also completed 3 stability ball exercises: birddog, hip bridge, and ball back extension.
- No significant differences were observed in the rectus abdominis and external oblique muscles during any of the exercises.
- Activity of the trunk muscles during squats and deadlifts is greater or equal to that which is produced during the stability ball exercises. Squats and deadlifts are recommended for increasing strength and hypertrophy of the back extensors.
In short, this study showed that squats and deadlifts elicit high levels of activation in the posterior core muscles (i.e., the back extensors) when compared to other exercises that target the posterior core muscles.
But they didn't compare squats and deadlifts to exercises that are designed to activate the anterior core (abdominals and obliques) musculature.
Additionally, the following graphs help give you a visual of just how much or, more accurately, how little the anterior core muscles are activated during squats and deadlifts as opposed to other anterior core-specific exercise applications.
As you can see, according to this research, squats and deadlifts don't even come close to creating the levels of activation in the rectus abdominis that the push-up does.
Likewise, the graph below shows that squats and deadlifts create higher levels of muscle activation in the external obliques than they do in the rectus abdominis. However, the level of external oblique muscle activation is still well below that created by the push-up!
Complete Core Training Requires More than Squats and Deads!
If you seek to posses a truly strong "core" you need to be training all of the muscles of your torso.
We know that pushing exercises provide plenty of work for the pecs and shoulders. We also know that upper-body pulling exercises provide plenty of work for the lats and mid-back musculature. And now we know that squats and deadlifts work the heck out of our posterior core muscles.
But that leaves out the anterior core muscles (abs and obliques), which is what people generally want to work when they toss the word "core" around!
So, what move or moves offer the most benefit for working these anterior core muscles?
The Pike Roll Out: The Single Best Ab Exercise
A 2010 study compared core muscle activation during Swiss ball and traditional ab exercises and found that the Swiss ball rollout and the Swiss ball pike were the most effective in activating the upper and lower abs and external and internal obliques.
So, I combined the two to make what I call the "single best ab exercise." It's called the pike rollout.
Of course, a comprehensive abdominal training program, like training any other musculature, should include several different exercise applications to ensure your workouts are well rounded.
Related: More smart ways to train your abs
- Dominguez, R, and Gadja, R., "Total Body Training" New York, NY: Charles Scribner's Sons; 7-12, 1982.
- Martuscello JM, et al. "Systematic review of core muscle activity during physical fitness exercises" J Strength Cond Res. 2013 Jun;27(6):1684-98.
- Nuzzo JL, et al. "Trunk muscle activity during stability ball and free weight exercises" J Strength Cond Res. 2008 Jan;22(1):95-102.
- New Training Techniques. Powerpoint presentation by Jeffrey M. McBride, PhD Associate Professor - Biomechanics Department of Health, Leisure & Exercise Science Appalachian State University, 2006.
- Escamilla, R.F, et al. "Core muscle activation during Swiss ball and traditional abdominal exercises" J Orthop Sports Physical Ther, 40: 265-276, 2010.