Revamp Your Ab Workout with These Deep-Core Exercises.
Certified personal trainer Tanya Poppett suggests six deep-core exercises that target midsection muscles often missed by sit-ups and crunches. The workout requires only a pillow and takes about 20 minutes to complete. Working these muscles boosts stability, performance in full-body compound exercises, and reduces strain on the lower back. The use of a pillow provides an "external cue" to perfect technique and activate core muscles.