To rehab your abs from the inside out, you need to start by strengthening your deepest abdominal muscle, your Transverse Abdominis, or TvA. This is your body's internal girdle, and when contracted, compresses the abdomen and pulls the abdominal wall closer to the spine.
TvA Isolation:
1. Lie on your side, with a neutral, elongated spine, knees slightly bent. Have a thin pillow under your head.
2. Allow your belly to fully relax, and yeah, when your postpartum everyone's belly will be lying down next to you.
3. Inhale deeply. Exhale slowly, making a strong hissing sound, as you simultaneously contract you abs, pulling your belly off the floor and closer to you spine. Take care that you DO NOT move your spine, just tummy.
4. Breath normally for several breath cycles as you maintain the contraction of your TvA. Then exhale, release the contraction and allow your belly to soften.
5. Perform 5 repetitions. Try to do this exercise on most days of the week. This exercise is safe to start directly after childbirth, with both a vag or C delivery.