If you’ve ever had to zip up in a pair of jeans that are too small, the way you had to scoop in your belly is what’s known as abdominal hollowing. The muscle responsible for this drawing-in movement is the transversus abdominis, or the deepest layer of your abdominal muscles. It surrounds your midsection like a girdle and helps to stabilize and protect your lower spine. Abdominal hollowing is a type of isometric exercise that activates the transversus abdominis and can be performed in various positions -- sitting, standing and on all fours.
Locating the Muscle
Abdominal-hollowing exercises help you to activate and control the transversus abdominis, building your core strength. Since the muscle is buried in your body, locating it before you start the exercises is helpful. Stand with your spine in a neutral position. Form a triangle with your hands directly over your pelvis. Cough forcefully to feel the transversus abdominis contract. Breathe naturally and become aware of this muscle’s movement.
The focus of abdominal-hollowing exercises is to draw your belly button toward your back, which hollows out your stomach and shrinks your waist. You want to contract the transversus abdominis but not clench it in a rigid or tense way. While the exercise can be performed in virtually any position, it’s best done on all fours. When in the kneeling position, align your hands under your shoulders and your legs beneath your hips. Maintain a straight back. Inhale and allow your stomach to relax and drop. Exhale and slowly pull your navel in toward your spine. Hold until you need another breath, then return to the starting position. Perform 10 to 15 reps for two or three sets, resting two to three minutes between sets.
The Pelvic Floor
When you do the abdominal-hollowing exercise lying face-down on the floor, you can develop control over your pelvic floor. Lie on a mat and rest your forehead against a folded towel. Place your arms by your sides, pointing forward with elbows bent at 90-degree angles and palms down. Reach forward with your head, elongating your spine. Inhale deeply and slowly draw your navel toward your spine; avoid lifting your hips. Hold the peak position for five seconds and exhale. Inhale and return to starting position.
To increase the difficulty of the exercise, you only have to add small movements. For example, get on all fours to perform the abdominal-hollowing exercise. Use the same form, scooping in the navel toward the spine. Hold the sucked-in position through the exercise, continuing to breathe in a relaxed and normal way. Raise one hand and the opposite knee slightly off the ground to assume a modified horse stance. Hold this position for 10 seconds, then repeat with the other hand and knee. Perform 10 reps for two or three sets, pausing for two to three minutes between sets.
Kay Tang is a journalist who has been writing since 1990. She previously covered developments in theater for the "Dramatists Guild Quarterly." Tang graduated with a Bachelor of Arts in economics and political science from Yale University and completed a Master of Professional Studies in interactive telecommunications at New York University.