Before you do those crunches, read this!
During the third trimester of pregnancy, babies grow rapidly and put increasing pressure on the abdominal muscles. That pressure can cause the rectus abdominis, a paired muscle running vertically down the front of the abdomen, to separate. This separation is called diastasis recti, and it can occur to various degrees above or below the belly button.
If not corrected postpartum, diastasis recti advances with each pregnancy, and may lead to less abdominal support during future pregnancies, which increases lower back pain and poor posture.
To check for separation, lie flat on your back and lift your head and shoulders off the floor. You should be able to feel the two straps of muscle running vertically along the midline of the abdomen. One or two fingerwidths of space between the two straps is common postpartum. This degree of separation is common in women following the birth of a baby and can be corrected by doing modified abdominal exercise, says Skylar Hill-Jackson, founder and director of Baby & Me Fitness in Toronto. The exercises below pull the two sides of the rectus muscle toward the midline to stabilize and support the abdomen.