Should you suck in your abs when exercising? Here are the pros and cons on sucking in your abs during exercise.
Should you suck in your abs?
EMGs and computerized movement analyses show that good athletes don’t suck in or draw in the navel during exertion. The body quite naturally responds to force production with a brief (and important!) breath holding reflex (the Valsalva) that is accompanied by an outward bulging of the abdominal muscles. Outward bulging of the abdomen is a perfectly natural and important action associated with trunk stabilization during force production.
Why go against a natural reflex and pull in, if your nervous system is doing a perfectly competent job on its own by guiding you to push out? A healthy body automatically uses the transversus and other deep muscles to stabilize the spine before initiating any movement of the limbs themselves. Any deliberate attempt to pull the abs in changes the natural firing patterns of the spinal support system, and produces a tendency towards spinal flexion, which is not what anyone wants when squatting, lifting a load from the ground, or lifting overhead.
When should you suck in your abs?
Research clearly indicates that folks who have low back pain (LBP) generally show weakness and/or poor motor control of the inner abdominal stabilization system (like transverse abdominis, pelvic floor, multifidi). Intentionally flexing (and subsequently strengthening) these muscles is a documented way to decrease back pain in many individuals. Sucking in has been shown to decrease SI joint laxity, and may be appropriate for decreasing back pain in certain populations with sacroiliac joint issues too.
Abs in or out during exercise?
If the individual has a healthy back and good athletic abilities, chances are that we would disrupt an already high-functioning support system by trying to artificially change the intrinsic actions of the Inner trunk musculature. Let the nervous system do what it already does well. A proper Valsalva maneuver (not sucking in!) will generate optimal spinal support and stabilization.
However, If the individual does not exhibit the ability to execute a good Valsalva with adequate spinal support, then intentionally drawing in the midsection while performing various movements will give better support than none at all. If you can’t brace well, sucking in the abs is better than not having any support at all! The goal should be to both strengthen the Inner core musculature, and to train the nervous system to recruit these muscles in a natural fashion so that intentional drawing in will no longer be necessary.